Pacemaker Boats Forum Index Pacemaker Boats
Information exchange on Pacemaker/Aglas Boats
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Refi

Bookmark this site!
yet another overheating problem!!
Goto page 1, 2, 3  Next
 
Post new topic   Reply to topic    Pacemaker Boats Forum Index -> Engines and drive train
View previous topic :: View next topic  
Author Message
acabedo
Mate
Mate


Joined: 12 Oct 2006
Posts: 49
Location: Gibraltar

PostPosted: Tue Oct 23, 2007 12:23 pm    Post subject: yet another overheating problem!! Reply with quote

Hi all, back again after a long hot and sometimes bothersome summer! Managed to more or less get some usage out of the boat the last couple of months but kept suffering from a very odd problem....
when I come to start the engine after some hours, the saltwater strainer is empty of water, as a consequence, the pump seems unable to start the water flowing and with no liquid, the impeller and housing gets very hot and a great side effect is that the flexible exhaust hose gets too hot and ruptures, sending gallons of water into the bilge and exhaust fumes all over the place!! The hose isn't exactly cheap either!

The rubber seal on the strainer is fine and there is no sign of water leakage in the area of the strainer or the pump. At idle I can see the shaft of the impeller turning. The only way I can use the boat at the moment is to sit by the engine and feel for the impeller cover to start to heat up, when that happens I stop the engine, top up the salt water level in the strainer and start her up again. After repeating this a couple of times it generally runs fine as long as I don't stop the engine again! As you can well imagine, this is not a very practical way of running things!

On occasions the cover still got hot, but not because there was no water, the water was there but hot enough to make a cup of tea, I can only assume some horrific blockage that the impeller couln't cope with and hot water was being pushed backwards down the system!

I have thought about the problem and the only thing I can come with is some kind of air leak at a level above the strainer that is allowing the water to slowly drain away over time......except that the strainer is the highest thing in the system! So now I give up and throw myself at the mercy of those who know more than I about ruddy engines...over to you guys, any and every comment welcome!

Did manage to get some fish though, I'll try to upload photos of them soon.
_________________
Adrian
Back to top
View user's profile Send private message Visit poster's website AIM Address
changeofpace
Site Admin
Site Admin


Joined: 12 Oct 2006
Posts: 599
Location: New Haven CT - Long Island Sound

PostPosted: Tue Oct 23, 2007 11:12 pm    Post subject: Reply with quote

Hey Adrian, sorry to hear your having problems. have you tried just replacing the water pump? Does it turn the right way? if its spinning backward, it wont pull enough water up into the cooling system. If the strainer is below the water line, the weight of the boat should keep the water in the strainer. If you open the shutoff valve does a lot of water come out the hose? Could also be a plugged intake fitting. Try blowing air through backwards so if there is a plug, it will blow out of the thru hull fitting. Just some thoughts
Terry
Back to top
View user's profile Send private message Send e-mail
acabedo
Mate
Mate


Joined: 12 Oct 2006
Posts: 49
Location: Gibraltar

PostPosted: Wed Oct 24, 2007 1:43 am    Post subject: Reply with quote

The strainer part of the pump is new, as is the impeller and I assume the thing is turning the right way because eventually it seems to run ok but bvecause it's an intermittent problem it's difficult to get to grip with it.
the strainer is well above the water line which is I think why it's emptying. I think blowing some water or air backwards through the system might be an idea though...
_________________
Adrian
Back to top
View user's profile Send private message Visit poster's website AIM Address
changeofpace
Site Admin
Site Admin


Joined: 12 Oct 2006
Posts: 599
Location: New Haven CT - Long Island Sound

PostPosted: Wed Oct 24, 2007 8:45 am    Post subject: Reply with quote

silly question, since the impeller is new, are the cups (flappers) going the right way so that they scoop up the water and throw it up the hose?
Back to top
View user's profile Send private message Send e-mail
acabedo
Mate
Mate


Joined: 12 Oct 2006
Posts: 49
Location: Gibraltar

PostPosted: Wed Oct 24, 2007 2:20 pm    Post subject: Reply with quote

yes, I checked, the confusing thing is that it is intermittent, when it feels like it all works beautifully and then when you have relaxed it catches you by surprise! Mkes for very unrelaxed boating!
_________________
Adrian
Back to top
View user's profile Send private message Visit poster's website AIM Address
changeofpace
Site Admin
Site Admin


Joined: 12 Oct 2006
Posts: 599
Location: New Haven CT - Long Island Sound

PostPosted: Wed Oct 24, 2007 2:49 pm    Post subject: Reply with quote

Well Adrian, It has me stumped unless its the thru hull fitting is plugged, the part thats on the bottom of the boat. Could be overgrown and blocking the water flow. I would think though that if that was the case you would see the overheating all of the time. You said that the water pump gets hot enough to burst the hose. In my experience, that should also destroy the impeller since they are made out of rubber.
Is this is a closed cooling system or completely raw water cooled system?
Back to top
View user's profile Send private message Send e-mail
acabedo
Mate
Mate


Joined: 12 Oct 2006
Posts: 49
Location: Gibraltar

PostPosted: Wed Oct 24, 2007 3:15 pm    Post subject: Reply with quote

I've disconnected the pipe from the bottom of the saltwater pump and blown down it and it seems clear, also when I remove the tube from the through hull fitting water pours in nicely.

What has burst before now is the flexible exhaust hose that goes from the exhaust elbow to the transom when the saltwater stops flowing through the hose. What has heated up is the water in the saltwater strainer, but the impeller still seems ok, it wasn't boiling but definitely hot. The engine has a sealed fresh water system that is cooled by a heat exchanger. The freshwater part seems ok. I suspect that I will have to slowly dismember the cooling system until I find what I presume is a blockage, or an air lock, I can't think of what else would cause these problem.
_________________
Adrian
Back to top
View user's profile Send private message Visit poster's website AIM Address
changeofpace
Site Admin
Site Admin


Joined: 12 Oct 2006
Posts: 599
Location: New Haven CT - Long Island Sound

PostPosted: Wed Oct 24, 2007 10:16 pm    Post subject: Reply with quote

Maybe the flexible hose is collapsing enough to restrict the water flow. Does the hose have the wire inside it or is it just a soft wall hose. Seems like there isnt any blockage of water coming in, the engine is closed, so the raw water comes in through the strainer and then maybe through the tranny cooler, the heat exchanger and out the riser. How old are your risers? Pull the hose fittings off of them and see if they are clean. make sure you seal the threads with teflon tape when you put them back in or they will leak
Terry
Back to top
View user's profile Send private message Send e-mail
rebait
moderator
moderator


Joined: 27 Oct 2006
Posts: 482
Location: Bayville, N.J.

PostPosted: Thu Oct 25, 2007 8:59 pm    Post subject: Reply with quote

Adrian,

A few questions:

1. Did this problem start after anything else was changed or modified?
2. If so, what?
3. Does the pump have an insert that the impeller blades contact?
4. If it has the insert was it changed with the impeller?
5. Was the strainer raised or moved before you had this problem?
What I would do:
1. If I did not have a manual on the cooling system, I would purchase it before going any further. I would go to the trouble shooting area and see if any of these symptoms are listed and take the recomended actions first. If there is a number to call, I would see if they have tech support. If no manual is available I would go to #2.
2. If nothing was modified or replaced I would go to #3. If the answer is yes, I would see if that modification had any effect on it.
3. If the pump has an insert and I did not change it I would change the impeller and insert and be sure that the blades are facing correctly. If it does not have an insert I would consider replacing the pump assy. The housing may be warped not letting the impeller form a correct seal.
Good luck and let us know how you make out,

John
Back to top
View user's profile Send private message
leokow
moderator
moderator


Joined: 12 Oct 2006
Posts: 415
Location: Osborn Island, NJ.(Little Egg Harbor)

PostPosted: Wed Oct 31, 2007 1:51 pm    Post subject: Reply with quote

Hello Adrian, I'm really sorry to hear that you're having problems again but I'm sure somehow it'll get repaired. You said the water runs out of the strainer, have you checked the seal on the top of it ? It sounds like the pump is sucking air from someplace and that would have to be between the pump and the water inlet. The reason your flex hose melted was because it was getting raw hot exhaust blown into it with no waste water to cool it down, the waste water and exhust mix at the last elbow before the rubber exhaust line.
Did you remove the hose on the outlet side of the pump and turn the engine over to see if the water was pumping OK to that point ? If it is ok to there then I would check the heat exchanger for blockage that would prevent the pump from sucking by causing too much back pressure.
You can check that too by removing the hose that dumps the hot salt water from the exchanger into the riser where it then goes out the exhaust.
The salt water cooling side is the easiest to fix as it only goes to the heat exchanger then out to the sea again, I'm saying easier compared to the freshwater side of the system, I'm not trying to say that the problem itself is easy, there doesn't seem to be any easy problems on a boat.
My best guess would be that you are sucking air or that pump is bad, try checking the pump the way I said , it won't hurt the engine to run for a minute, the fresh water system will keep it cool for longer than that.
However, if there's no water coming out of the pump with the outlet hose disconnected then your problem can only be from the pump to the intake port. I have seen some pumps with tiny cracks in them that only open when they are under pressure and that lets the pump lose suction, but most of the time you will see a green streak of corrosion on the body of it as the sea water seeps out when the pressure is off. Adrian, I sould have asked you this first...were any kinds of repairs or modifications made before this started or did it just begin on its own ?
Good luck and I hope you find this soon ...Leo
Back to top
View user's profile Send private message Send e-mail
acabedo
Mate
Mate


Joined: 12 Oct 2006
Posts: 49
Location: Gibraltar

PostPosted: Wed Oct 31, 2007 4:24 pm    Post subject: Reply with quote

Hi again guys, sorry for ther delayed reply, trying to finish a commision for a client!
The problem seems to have started after I caught a plastic bag in my intake grill and it affected the freshwater pump which I replaced completely at the time. I'm not sure what insert you mean by inserts that the impeller contacts. The engine was supposed to have been "reconditioned" by the guy who sold it to me, but I'm slowly discovering that the job wasn't as complete as it should have been, some parts just seem to have been taken of another engine and slapped on mine without so much as a basic clean!

The strainer was also completey replaced by me earlier on but is in the original position, it's at the highest part of the saltwater system.

I used the boat again today and again, the impeller housing heated up and I had to remove the top of the strainer, top up with water and restart, three times! The third time the water was not only low but hot, so I can only assume a blockage somewhere down the line, I guess I really need to start at one end, (perhaps at the exhaust elbow) and work my way right round the system until I find the problem/blockage.

What I still can't figure out though is why the level of the strainer gets so low, all the seals around the strainer and its top seem fine and there is no sign of water leakage around the area.

I shall persist until either I or the engine wins!!

I shall let you all know who wins!
_________________
Adrian
Back to top
View user's profile Send private message Visit poster's website AIM Address
changeofpace
Site Admin
Site Admin


Joined: 12 Oct 2006
Posts: 599
Location: New Haven CT - Long Island Sound

PostPosted: Wed Oct 31, 2007 4:42 pm    Post subject: Reply with quote

Adrian, I think the only way for the raw water to get hot is from the exhaust since this is a closed cooling system. The water has a slight chance of heating up if you have a tranny cooler in the raw water cooling system. The raw water picks up the heat from the exchanger and is dumped out the riser with the exhaust. Since the water is heating up in the strainer, I would start with the exhaust manifolds, specifically the risers since this is where the water and exhaust mix. You should be able to remove the risers and see if the block off plate needs replacing and you should be able to see if the water passages are restricted. Since you said you had sucked up a plastic bag and the engine rebuild is questionable, its also possible the guy did not use a block off plate just a gasket and it has a hole in it. The exhaust pressure will blow the raw water out if the pressure is higher than the pump pressure. If the exhaust manifold was overheated when you sucked up the bag, it could have burned a hole in the block off. Just some ideas to check that are not expensive
Terry
Back to top
View user's profile Send private message Send e-mail
leokow
moderator
moderator


Joined: 12 Oct 2006
Posts: 415
Location: Osborn Island, NJ.(Little Egg Harbor)

PostPosted: Thu Nov 01, 2007 12:34 pm    Post subject: Reply with quote

OK Adrian, somethings getting all confused here, so let's begin again. First what engine is in your boat ? are the risers also cooled by antifreeze or are they also salt water cooled ?
Next, when you get an engine rebuilt it does not include all the accessories that are attached to the particular engine. They are just removed from your old block and replaced on to the rebuilt block.
Also, you don't want to start looking for your overheating problem from the exhaust back toward the engine, you need to do it the other way around. Try some of the things I posted last and let me know the results and then I can help you move forward from there. Was the boat running fine before you sucked up the plastic bag ?...Leo...
OK, I looked back at some of your old posts and found some info about your engine, it looks like its a diesel with an I/O drive hooked up to power it, if the picture you posted is correct, am I right so far , or is the transmission set up differently ? I do not believe that you have a blockage, it sounds more and more to me that the intake pump is bad, it is very possible that you burned it when you picked up the bag and ran it dry.
Back to top
View user's profile Send private message Send e-mail
acabedo
Mate
Mate


Joined: 12 Oct 2006
Posts: 49
Location: Gibraltar

PostPosted: Thu Nov 01, 2007 1:06 pm    Post subject: Reply with quote

Hi Leo,

ok, it's a Volvo Penta KAD32, regarding the risers, I'm not sure what they are, is it the elbow that connects to the turbo and then connects to the flexible exhaust hose? If it is this bit then it seems fairly old and in fact, where the hose connects to the elbow the metal is pretty worn and corroded (only just enough room to fix a hose clamp).

The engine was running fine before the plastic bag, although like I mentioned, when that happened it also ruined the fresh water pump which was completely replaced, (or at least it went at the same time). The problem seems directly related to that event, though knowing my luck it could be a coincidence and have nothing to do with it!

I did run the engine with the top of the strainer off, or at least loose and lots of water came out. Part of the problem is that the fault is intermittent, once you've replenished the water a couple of times it runs fine from then on (usually).

I think there may be two separate problems, one is the strainer emptying after not running the engine for a while, the other is hot water being pushed back into the strainer - just grasping at straws here!!!

In any case, I will try to start investigating as you suggest this weekend and keep you posted of any progress.
_________________
Adrian
Back to top
View user's profile Send private message Visit poster's website AIM Address
rebait
moderator
moderator


Joined: 27 Oct 2006
Posts: 482
Location: Bayville, N.J.

PostPosted: Thu Nov 01, 2007 11:04 pm    Post subject: Reply with quote

Adrian,

After reading the posts and thinking about it, if all the plumbing and connections are good from the intake to the pump and everything is exactly the way it was before the bag incident my inclination would be the raw water ( salt water ) pump. When it was replaced was it a new or rebuilt / reconditioned? Was the pump run dry for even a few seconds? If so it could have ruined the impeller and it has a hard time keeping a seal and prime. Even if there is a leak after the pump, it should not afffect the pumps ability to hold prime.

Just my opinion, Good luck, John
Back to top
View user's profile Send private message
changeofpace
Site Admin
Site Admin


Joined: 12 Oct 2006
Posts: 599
Location: New Haven CT - Long Island Sound

PostPosted: Fri Nov 02, 2007 9:12 am    Post subject: Reply with quote

Yeah John that was my thought also but it doesnt explain the water being hot enough to heat the pump housing, that can only happen if the water is backing up due to a restriction in the line or a small hole allowing the exhaust to heat the water. Exhaust pressure could blow the water back into the pump housing and when the engine is shut off, blow the water out of the strainer. Its also possible that a small amount of the plastic bag was sucked through the system and is creating a restriction. My experiences have shown problems like these are either the raw water or cooling pumps or the risers being plugged with marine growth or corrosion
Back to top
View user's profile Send private message Send e-mail
rebait
moderator
moderator


Joined: 27 Oct 2006
Posts: 482
Location: Bayville, N.J.

PostPosted: Fri Nov 02, 2007 11:03 pm    Post subject: Reply with quote

Terry,

We are dealing a number of unknowns. Too bad he is on the other side of the Atlantic or this would make for a great group meet and put our heads together, trouble shoot and solve the problem. My brother in law Dan had a very similar problem on his SeaRay when he first bought it. The previous owner started it up dry to made sure it ran before they put it in the water. He works the guy, an "experienced boater". That is another funny story. Needless to say, it wound up back on the trailer that night and Dan and I replaced the impeller the next day. But this can be a number of problems that surfaced at once brought on by the overheating caused by the plastic bag.

John
Back to top
View user's profile Send private message
changeofpace
Site Admin
Site Admin


Joined: 12 Oct 2006
Posts: 599
Location: New Haven CT - Long Island Sound

PostPosted: Sat Nov 03, 2007 9:29 am    Post subject: Reply with quote

I agree John, I thought that Adrian said the impeller is new since the bag was sucked up. I would love to have a meet and fix a problem like this. Maybe we should seek out a down-trodden Pacemaker and all fix it up for a deserving boat owner LOL!!!
Seriously, over-heating problems can be from many different things. Since Adrian doesnt say if the engine is running hot, only the raw water pump and the fact that it goes dry makes me suspect the manifold and risers. If it was me, I would first check the flow through the heat exchanger by taking off the cap and seeing if the water is moving through below the cap, the I would pull the raw water hoses and check for restrictions, next would be to drain the heat exchanger and inspect the tubing inside for corrosion. What I keep getting stuck on is that the water in the strainer is getting hot, that means it is getting heated by the engine, either in the exhaust system or in any heat exchangers he has.
Adrian, if there is a shut-off valve located by the strainer, if you close it when the boat sits, does the water still disapear or does pressure build up in the strainer basket?
Back to top
View user's profile Send private message Send e-mail
leokow
moderator
moderator


Joined: 12 Oct 2006
Posts: 415
Location: Osborn Island, NJ.(Little Egg Harbor)

PostPosted: Sat Nov 03, 2007 9:30 am    Post subject: Reply with quote

I agree with the both of you, lets take a trip to Gibralter and help out Adrian!! I only wish we could, anyway if you look at his post he says the water is only hot after the third try at trying to hold prime. This could be from the housing itself heating up because of no water to cool it down.
If he got a small crack in the housing when he overheated from the plastic bag incident then that would explain him not being able to hold prime or to get good suction on its own,until he floods it out a couple of times. If he just disconnectes to output hose of the salt water pump from where it connects to the heat exchanger it should push water in a stream at least 4 or 5 ft. away, when you try to start the engine. If it doesn't then the problem has to be from the pump to the bottom of the boat, right ? or am I missing something ?
There could even be a piece of the bag caught in the impeller of the pump,
I just wish I could get my hands on it for a few minutes, it's frustrating trying to fix things from 3000 miles away, but it's nice to try.
PS...I'm betting on that salt water pump,if there's not a suction leak.
Hopefully we'll know something after this weekend.
Back to top
View user's profile Send private message Send e-mail
acabedo
Mate
Mate


Joined: 12 Oct 2006
Posts: 49
Location: Gibraltar

PostPosted: Sat Nov 03, 2007 1:40 pm    Post subject: Reply with quote

I rather like the idea of you guys coming out! What a relief that would be! OK, back to reality, (though everyone from over there has an open invitation) I'm going to print out this post take it down to the boat and do pretty much everything evryone has mentioned, I'm hoping a more mechanically minded friend will join me down on the boat, I'm a bit of an amateur when it comes to taking bits of engine of!

Anyway I will post the results as soon as have some news, thanks again for the input, it gives me plenty to work with.
_________________
Adrian
Back to top
View user's profile Send private message Visit poster's website AIM Address
changeofpace
Site Admin
Site Admin


Joined: 12 Oct 2006
Posts: 599
Location: New Haven CT - Long Island Sound

PostPosted: Sat Nov 03, 2007 2:39 pm    Post subject: Reply with quote

Good idea about unhooking the hose, It should spray a lot of water when it spins. I kind of think there will be a piece of bag stuck in the cooling line somewheres. Like I said, I sometimes get stuck on a problem because I dont sit back and look at the whole picture. Adrian, if we could see some pics of the cooling system maybe we can see something that looks out of place or wrong
Back to top
View user's profile Send private message Send e-mail
rebait
moderator
moderator


Joined: 27 Oct 2006
Posts: 482
Location: Bayville, N.J.

PostPosted: Sat Nov 03, 2007 6:30 pm    Post subject: Reply with quote

Team,

Are we all in agreement to isolate the pump first? Disconnect the discharge line and see if we get a good flow. We should get water just cranking, but the true picture is to let it run for about 30 seconds. Adrian, I would hook a hose to divert the water away from the engine, the "cabin" under the console and you. Please let us know because this is keeping us thinking.

John
Back to top
View user's profile Send private message
merwin10
Site Admin
Site Admin


Joined: 11 Oct 2006
Posts: 440
Location: Buzzards Bay, Massachusetts

PostPosted: Sun Nov 04, 2007 12:30 pm    Post subject: Reply with quote

Ok Read all of the problem time to put my two cents in! Couple of things here - since you said you get good water flow when disconnecting the incoming hose from the hull fitting says that the fitting is not plugged. However that does not elimitate it! Have you added anything that would distrub the flow of raw water to the thru hull under way! If air is getting to the thru hull then it would cause air in the raw water pump.

Next suspect is the hoses - Some hose are multi ply hose and can separate - Although from the outside they look fine the inner ply breaks loose and the suction of the raw water pump collapses it cause a blockage.

Next is a bad seal on the strainer - if it is leaking then air is allowed in and the raw water pump is not pumping water. Leak in any hose clamps before the raw water pump does the same thing!

None of the above! Check the raw water pump itself - Although the impellor may look ok you need to bend each tab both ways and check for cracks at the center rotor. Also the end plates may be worn out due to air cavitation! The end plates need to seal against the impellor so air can't leak by -

Moving up the pressure side of the raw water pump are the oil coolers both engine and transmission any debris in the cooler here and you won't have good flow to the heat exchanger. One cause of this is actually corrodsion prevention. Pencil zincs in the coolers are there to prevent corrsion but they also tend to flake during use! The flakes get caught in the cooling tubes and plug them restricting the flow of raw water hence building pressure on the raw water pump causing it to cavitate and heat up! The same goes for the heat exchanger. Pencil zincs are there to help prevent corrsion but need to be inspected yearly to be sure they have not cloded the coolers - back flushing the coolers is one way to correct this issue - I run it into a five galon bucket to see if any deposits come out, then you know there is a problem.

Moving along the next issue is the exhuast risers if there is wear there you need to replace them as the exhaust pressure builds up it can blow back into the raw water cooling system - Any restriction in the exhaust can also cause a raw water back up - For example on my boat if I back down on a fish for an extended period of time, 30 minutes or more, I notice an increase in engine temperature. The reason for this is that while backing down the ehaust has rubber flappers that close when backing down and only open when the exhaust pressure is greater than the backing down pressure to hold them shut. The rubber flappers are to keep the ocean water from backing up into the mufflers and cracking them or blowing a exhaust hose off -

One thing that you mentioned that is puzzleing is why the strianer is above the water line. Most systems mount the strainer below the water line so that they can fill up to with in an inch or two of the raw water pump intake - Yes this means that if you take off the cap to the strainer the raw salt water runs right into the bilge.

Well that about covers the long and short of the raw water cooling system - Is the fresh water side OK not loosing any antifreeze? If you are loosing atifreeze and it is not in the boat the likey cause is a pin hole leak in the heat exchanger tubes. The pressure in the fresh water side is greater than the pressure on the raw water side and the antifreeze leaks into the raw water and goes out with the exhuast.

Well I hope this helps fine the solution to your issue!

Mike -
_________________
"Best part of Boating -- is the people you meet"
Back to top
View user's profile Send private message Send e-mail Visit poster's website
acabedo
Mate
Mate


Joined: 12 Oct 2006
Posts: 49
Location: Gibraltar

PostPosted: Sun Nov 04, 2007 6:00 pm    Post subject: Reply with quote

ok, back from the boat! Here's a summary of what I did and the results.

1. I disconnected the flexible exhaust hose from the elbow (see photo) and then I disconnected the outgoing hose from the bottom of the strainer and blew very hard down it, it was fairly easy and I managed to blow, both air and water out through the elbow. I then attatched a water hose to the tube and flushed fresh water through the whole system, water poured out of the other end from every part of the diameter of the elbow. At this point I don't think I have a blockage in that part of the system or the tubes, it was too easy to blow through!

2. I then removed the entire raw water pump and inspected every aspect, the impeller was fine, and the plastic bit at the back that drives the thing was also ok. I retightened all the jubilee clips and checked all the hoses that were connected to the pump/strainer and all seemed ok. The only thing that didn't seem right, was excessive wearing by the impeller on the cover, it was definitely not flat, this though has been the case since we bought the engine, I don't think it's the cause of these problems though I'm sure it may not help!

3. Connected everything back again and ran the pump without connecting the outlet, lots of water. Finally started the engine with a full strainer and momentarily closed the seacock a couple of times to try to create a stronger suction and clear any internal blockages or perhaps an airlock in the system. I ran the engine for about twenty minutes at idle and then a little faster and everything seemed to be working ok.

This dosen't really tell me that it's fixed as I would need to actually run the engine under load, the weather today wasn't exactly suitable!
I'm not sure if during my messing about I have accidently cured the thing, somehow I doubt it, and if I have it will be very frustrating because I'll never know what caused it in the first place!

The pump and strainer as you can see in the photo is how Volvo set it up, we haven't changed anything other than to completely disconnect the ridiculous supercharger, (you'll see the belt is missing in the photo).

As far as the hull fitting is concerned, I agree, just because water comes in ok when at a standstill dosen't mean that at speed a maverick bit of plastic dosen't occasionally move into position and block/reduce the flow. We plan to remove and replace it when we next come out.

The seal on the top of the strainer seems ok but I also want to change it, as that is the only place where I think there could be an air leak. I also replaced all the antifreeze in the freshwater system which is fine.

It dosen't sound like I've achieved much,even though I was down on the boat for about six hours, I guess my only hope is that I accidently sorted the problem. I'll have to wait until I can run the boat out for a while.

The biggest mystery for me is that it appears to be several distinct problems:

a - water dissapearing out from the strainer (or is this normal and it's just that the pump can't cope with restarting the flow).
b - occasional heating up of the water in the strainer
c - lack of flow into the raw water pump and overheating of the impeller

not sure how one connects these - anyway that's it so far, I will try to go out soon and report back on the results!




_________________
Adrian
Back to top
View user's profile Send private message Visit poster's website AIM Address
merwin10
Site Admin
Site Admin


Joined: 11 Oct 2006
Posts: 440
Location: Buzzards Bay, Massachusetts

PostPosted: Mon Nov 05, 2007 9:07 am    Post subject: Reply with quote

Hmm! The only thing I can think is that when the engine is off the air eventurally comes back thru the exhaust and all the coolers and bleeds air into the strainer. Since the stainer is above the water line it would then drain back into the ocean. You need to get air in to break the suction that the raw water pump has made to drain the strainer. In any case the air should NOT be able to bleed pass the impellor of the raw water pump as a least one blade is always colapsed sealing off the air to the strainer. A small leak at the cover plate could explain where the air comes from.

Question after shutting the engine off does the water in the strainer immediately drain out or does it take a few hours to drain? If it drains out immediately then there is a big air leak otherwise if it takes a few hours it is a small air leak. You need air beyond the suction side of the pump to drain the the strainer. Another idea is if the boat rocks enough to expose the hull fitting then air will be allowed in thru the fitting.

Maybe you fixed the issue but it would have been nice to find the problem so you can have peace of mind.

Mike - Rolling Eyes "thinking"
_________________
"Best part of Boating -- is the people you meet"
Back to top
View user's profile Send private message Send e-mail Visit poster's website
acabedo
Mate
Mate


Joined: 12 Oct 2006
Posts: 49
Location: Gibraltar

PostPosted: Mon Nov 05, 2007 9:42 am    Post subject: Reply with quote

it's very frustrating!! I haven't gone back to see how things are since yesterday, but normally when I remove the strainer top to check the level of the water, it has either already dissapeared or starts to flow out fairly rapidly. The strainer seems to be just above the level of the exhaust elbow so I guess it would follow that with time the water would seep out that way, although the exhaust goes out through the outdrive, what I'm not sure about is why the pump dosen't seem to have enough power to fill up the strainer again.

I shall give her a good run when the weather settles and see what happens!
Back to top
View user's profile Send private message Visit poster's website AIM Address
changeofpace
Site Admin
Site Admin


Joined: 12 Oct 2006
Posts: 599
Location: New Haven CT - Long Island Sound

PostPosted: Mon Nov 05, 2007 10:07 am    Post subject: Reply with quote

Adrian, Thanks for the pics, I cant see anything that looks too wrong. As for the water, what Mike says is correct, the rubber vanes should seal the pump. Since you said there is wear on the front of the housing caused by the impeller, I suspect that maybe the leak is there Quote from your post -"The only thing that didn't seem right, was excessive wearing by the impeller on the cover, it was definitely not flat," Since the cover isnt flat the seal may be questionable.
Back to top
View user's profile Send private message Send e-mail
leokow
moderator
moderator


Joined: 12 Oct 2006
Posts: 415
Location: Osborn Island, NJ.(Little Egg Harbor)

PostPosted: Mon Nov 05, 2007 12:27 pm    Post subject: Reply with quote

I know this is very frustrating,Adrian, but you have almost answered the question yourself. The water can not drain out of the strainer ,normally, unless you let air in from someplace on the back side of it. The top of the impeller sounds like a prime candidate. If you can get some vaseline or grease and put it around the edge and screws it may just be sealed enough to let you know that that is definitely the problem and then you can replace the pump and feel comfortable about the fix.If it doesn't work you can easily wipe off the vaseline and keep looking.
You have to keep in mind that the water can not come out unless air can get in. Wether thru the pump , the clamps or the hoses connected to them you should focus your efforts on the pump , strainer area.
How about the seal at the top of the strainer ? If that seal is leaking air, that could cause the loss of suction and also cause air to be pulled into the impeller causing it mix air and water but lose suction and let the hot water from the spinning impeller go back into the strainer,the hot water could be generated by the impeller spinning inefficiently due to the air mixing in.
If you have a doubt about the strainer seal , you could also use the vaseline or grease on the seal and tighten it down , it wouldn't hurt anything.
The pump should be strong enough to reprime itself if everything is operating properly and there aren't any air leaks, so what's happening to you is not normal.
Whatever you decide to do, only do one at a time and then test it, that way if it gets fixed you'll know which part is the bad one.
Back to top
View user's profile Send private message Send e-mail
rebait
moderator
moderator


Joined: 27 Oct 2006
Posts: 482
Location: Bayville, N.J.

PostPosted: Tue Nov 06, 2007 12:32 am    Post subject: Reply with quote

Adrian,

My opinion, start with the pump. Do as Leo said with using Vaseline (Petroleum Jelly) to form a seal. Test 1 component at a time. My gut feeling is that it is the pump and it may be that the whole assy. must be replaced. Test before replacing. See how much water comes out of the dicharge side of the pump after it is hot. Use heat resistent, water proof gloves such as the old Red Ball gloves that the firemen used to use and eye protection. (sounds as if I am at work). I feel that the pump acts up after it has been run for a while.

John
Back to top
View user's profile Send private message
leokow
moderator
moderator


Joined: 12 Oct 2006
Posts: 415
Location: Osborn Island, NJ.(Little Egg Harbor)

PostPosted: Wed Nov 07, 2007 4:35 pm    Post subject: Reply with quote

I agree completely, my feeling from the beginning was the pump, but I don't think a kit will fix it, I believe if it's bad , you may need to buy the whole unit.
The fact that it all worked when you put it back together makes me feel that way even more. A blockage won't cause the water to drain out of the strainer, so unless there are two problems,a block doesn't fit the bill.
There must be a suction leak at some point or a bad pump,or a pump going bad.
Of course I will feel really stupid if it's something else, but this wouldn't be the first time.LOL A little humor will keep us all sane, good luck, Adrian.
Back to top
View user's profile Send private message Send e-mail
acabedo
Mate
Mate


Joined: 12 Oct 2006
Posts: 49
Location: Gibraltar

PostPosted: Tue Nov 13, 2007 12:10 pm    Post subject: Reply with quote

ok, brief update (and a login!), finally got to use the boat again yesterday, same sort of problem, with the impeller cover getting hot/warm almost immediately, but this time only some of the water dissapeared. The strainer was half full/empty so I'm not sure what was causing the heating. After two top ups it run perfectly for the rest of the evening.

Now I have to try to identify an electrical fault that switches everything on and off all the time!!
I love boating!
I'll report back after a few more tests, see how it goes.
_________________
Adrian
Back to top
View user's profile Send private message Visit poster's website AIM Address
changeofpace
Site Admin
Site Admin


Joined: 12 Oct 2006
Posts: 599
Location: New Haven CT - Long Island Sound

PostPosted: Tue Nov 13, 2007 3:28 pm    Post subject: Reply with quote

Adrian,
sounds like a crossed wire or bad ground. Did this happen before you took things apart to fix the water pump?
which circuits are affected? running lights? any of your gages acting funny?
cant say for sure about your pace, but mine has a common ground for each engine and its set of gages. There is a common white ground wire that comes up from the dc panel to the control area. start by checking the connections, looking for loose or green colored fittings. when checking the connections, give the wire a little tug to see if its solid, it could be that only a few strands of wire are all thats left. I had problems and it was mostly due to bad grounds. When I first got my pace and finally got to where I could put the batteries in, there wasnt any power to the ignition switches, neither of the engines or inside lights would work. The ground wire on the dc panel was no good. After that was fixed, the tach lights would be on unless I killed the battery switch, again bad ground wire was causing 12 volts to go through the lights since they in effect were becoming grounds. take your time and pick one system at a time and you'll find it
terry
Back to top
View user's profile Send private message Send e-mail
rebait
moderator
moderator


Joined: 27 Oct 2006
Posts: 482
Location: Bayville, N.J.

PostPosted: Tue Nov 13, 2007 10:36 pm    Post subject: Reply with quote

Adrian,

Must be a Wahoo thing. I am planning on going over my wiring this March. I am not crazy about what a previous owner has done. Let us know what you find. I believe everything


John
Back to top
View user's profile Send private message
leokow
moderator
moderator


Joined: 12 Oct 2006
Posts: 415
Location: Osborn Island, NJ.(Little Egg Harbor)

PostPosted: Fri Nov 16, 2007 4:18 pm    Post subject: Reply with quote

This water problem is starting to give me a headache now !! If the strainer is half empty when you try to start it and the pump won't prime enough to fill it, there has to be an air leak on the fill side of the pump.
What gets me is after you top it off twice everything is ok. A leak can't be fixed by topping off the canister, as soon as you slow down or stop you should end up right where you started, with no water in the strainer and loss of prime, but you said the thing ran fine the rest of the time.
I can't wait for you to tell us what you finally find.
Adrian, one reason the water starts to run out when you take the top off is the way that strainer is set up , the minute you take the top or loosen it , you let air into the back side and the suction is broken, letting the water run back out the intake. Anyplace that air can get in from the pump back to the strainer will do the same thing, but if the pump is good , then it should pull and fill it back up immediately.
Do you have a seacock at the bottom of the intake line that goes to the strainer ? If you do , the next time you shut your engine down ,close that sea cock and then take the top off the strainer and see if the water disappears. If it doesn't run out, then I think you can be fairly sure that your water pump is bad, and I don't think a kit will fix it, you will probably need the complete unit. Let us know how you make out and good luck...Leo
Back to top
View user's profile Send private message Send e-mail
changeofpace
Site Admin
Site Admin


Joined: 12 Oct 2006
Posts: 599
Location: New Haven CT - Long Island Sound

PostPosted: Fri Nov 16, 2007 10:34 pm    Post subject: Reply with quote

Leo what do you think about there being a small leak that seals itself when the pump heats up and the metal expands? still, that doesnt explain the pump not getting enough suction to fill the strainer. My pumps will suck 5 gallons of water in less than a minute with the 1 1/4 supply hose in a bucket. I tried to see Adrians raw water pump in his pictures to see if there is a flusher or something else that was added that might be leaking air into the system since it should be sealed by the flappers on the impellor of the raw water pump. Gravity should keep the strainer from going empty during storage unless its above the water line. I couldnt see anything that looked out of place. Still wish I could go and tinker on it and then go catch one of those fish he showed in the fishing section!
Back to top
View user's profile Send private message Send e-mail
acabedo
Mate
Mate


Joined: 12 Oct 2006
Posts: 49
Location: Gibraltar

PostPosted: Sat Nov 17, 2007 4:06 am    Post subject: Reply with quote

I'm not sure what happened, but a couple of days ago I took her out and purposefully didn't open the strainer to check the level of water (though I did sit beside the engine to feel for the first signs of heating) and without any priming the engine ran perfectly all day, nothing heated up and no top ups required! I thought great, I must have accidentally touched something and cured the problem!

No such luck! I went out again last night and after a good start the impeller cover heated up again, I took of the strainer cover and there was still water in there, it was warm and slowly filling up instead of going down! A few bits of muck appeared in the strainer (a strand of nylon, I think, about an inch long and a flake of something), after a moment it started to go down again. After a top up everything was fine again for the remainder of the trip.

I'm beginning to suspect that there may be an obstruction at the skin fitting that occasionally gets in the way, actually, thinking about it, the problem mainly seems to happen when we're under way. The strainer is above the waterline, so it makes sense that if there is a leak somewhere above the raw water pump that it will find its own level eventually. There's no flusher or other taps near the strainer, the only one is the sea cock on the hull.

The electrical problem I thought was a negative clamp on the battery which was very slightly loose, when I tightened it it seemed to sort the problem but nay, it came back again last night. It does however seem to get better when you throttle up.

I shall keep you posted................!

As to coming over to tinker and fish....yes please!!!
_________________
Adrian
Back to top
View user's profile Send private message Visit poster's website AIM Address
rebait
moderator
moderator


Joined: 27 Oct 2006
Posts: 482
Location: Bayville, N.J.

PostPosted: Sat Nov 17, 2007 11:18 pm    Post subject: Reply with quote

Team,

I just loked at the pictures and I have never worked on or even seen this type of diesel. Adrian, I am assuming that the strainer is the canister mounted above what appears to be the pump. Is the strainer mounted on the intake or discharge side of the pump? The reason why I ask this is that normally the intake is on the lower end of the pump so that air can be discharged easier. Every boat that I have seen has the strainer mounted on the intake side of the pump to keep debris out of it. Maybe the nylon strand and flake are pieces of the pump if it is on the discharge side? Maybe the top of the canister is not forming a tight seal? What is everyone's thought on this?

Electrical problem: when looking at the picture I noticed what appears to be a negative battery cable, the black one making the loop in the fore front in the picture seems to have a bulge in it. Maybe it has corrosion inside the casing.

Adrian, I would love to take you up on the tinker and fish trip. Too bad that I can't make it this year. If the offer is still there when I retire in a few years you may see me at your door. Maybe we can convince the rest of the team to go also.
Lets all put our heads together. I sure wish that I could see this in person.

John
Back to top
View user's profile Send private message
leokow
moderator
moderator


Joined: 12 Oct 2006
Posts: 415
Location: Osborn Island, NJ.(Little Egg Harbor)

PostPosted: Mon Nov 19, 2007 1:25 pm    Post subject: Reply with quote

John, I'm assuming that the left side of the canister is going straight down to the sea cock shut off, as it really wouldn't make sense to put the strainer on the output side of the pump. The picture doesn't show us down low enough to see but I'm assuming that's the way it's hooked up.
Adrian , I still think it's the pump, gut feeling, but the draining of the strainer when you open the top is easy to explain, unless I'm missing something. When you open the canister top you let air enter the suction side of the loop and beings that the strainer is the highest point of the system the water immediately starts to drain out the bottom of the boat. Just for kicks the next time it's running right when you shut it down, close the sea cock before you open the strainer top , and see what the water does then. If there's no leaks in the fittings or hoses from the canister to the sea cock the canister should stay full.
If it does stay full, the get some grease and put it around the seal on the canister top, put it back together, open the sea cock and run the engine ,see what happens then. Just a small air leak at the canister top ,the way you are set up , would cause a problem like you are describing. Also look real close at the clamps on the suction side , see if any of then have worked their way into the hose to cause an air leak. I'm trying to eliminate everything except the pump, so if the problem remains then the only thing left will be the pump. PLease let us know...Leo
Back to top
View user's profile Send private message Send e-mail
acabedo
Mate
Mate


Joined: 12 Oct 2006
Posts: 49
Location: Gibraltar

PostPosted: Mon Nov 19, 2007 4:57 pm    Post subject: Reply with quote

guess what, the strainer is connected after the pump, I've looked at a couple of other boats that have the same engine and that's how volvo have set it up!
Doesn't make too much sense to me either but there you are. Yesterday (for the first time), I did notice a tiny drop of water rolling down from the area of the top on the strainer, I can't see any obvious crack or leak but I assume that there is something there that isn't right.

Actually today I bought a complete new strainer (not Volvo) with a clear top which I want to try to install instead, I need to get various connectors and adaptors to make it fit, should I put it above or below the water line, and I suppose that before the pump would be a better idea!?

I took the alternator to a specialist today and he's going to look at it though after a brief test he said it seemed ok, and that it didn't seem to be the regulator, so we'll see in a couple of days, in the meantime I shall check all the wiring and connections including that fat black one![/u]
_________________
Adrian
Back to top
View user's profile Send private message Visit poster's website AIM Address
merwin10
Site Admin
Site Admin


Joined: 11 Oct 2006
Posts: 440
Location: Buzzards Bay, Massachusetts

PostPosted: Mon Nov 19, 2007 9:26 pm    Post subject: Reply with quote

I would recommend putting the new strainer before the the raw water pump and below the water line so it will fill up by itself. Hope you have the correct strainer for the water flow needed! Double clamp everything before the pump! I double clamp all pressured hoses as clamps seem to rust out and when they do you might not know until the engine overheats.

So you know the placement of the strainer from the sea cock double clamp the hose there. The other end of the hose goes to the inlet side of the strainer. YES strainers have a correct direction. The output side of the strainer is double clamps and this hose goes to the inlet (suction side) of the raw water pump, double clamp again! The output side of the pump goes directly to where the output side of the current strainer goes. Eliminate the current strainer! You can double clamp here also!

You may want to test where the water line is so you know. Loosen the top of the new strainer if water comes out you know it is below the water line. Somewhere between the strainer and the hose to the suction side the water will not run out, as it is above the water line. This is just a nice to know where the raw water will fill too. For example on my boat I know the raw water will fill the strainer and the output hose to within 1 inch of the raw water pump. This leaves very little space for anything to go worn where the pump would not be able to draw water!

Remember if you inspect the raw water pump impeller and there are pieces missing you need to answer where are the pieces. If they get caught in any of the coolers or heat exchangers they can cause overheating. A full inspection is needed to make sure that the pieces passed overboard. YES this can be a pain!!!!!!

Hope this helps!

Mike - Rolling Eyes
_________________
"Best part of Boating -- is the people you meet"
Back to top
View user's profile Send private message Send e-mail Visit poster's website
rebait
moderator
moderator


Joined: 27 Oct 2006
Posts: 482
Location: Bayville, N.J.

PostPosted: Tue Nov 20, 2007 12:39 am    Post subject: Reply with quote

Team,

I guess I saw it right, the strainer is mounted on the discharge side. I wonder why it was mounted like this. I am going to try and get hold of one of our guys at work who is also a marine mechanic. He works in another location now and I will ask him about these Volvo diesel pumps.
This might not be wrong ( for the life of me I don't know why ) but I have seen some strange things come from manufacturers. The engine ran fine before or did it?

John
Back to top
View user's profile Send private message
Anonymous
Guest





PostPosted: Tue Nov 20, 2007 7:28 am    Post subject: Reply with quote

thermostat's good ? no crack's in the block ? can you bypass the strainer to see what happen's ? question's i was asked when i tried to explain this to a mariner. the plastic bag thing having been sucked up has me wondering to ,could there be a chunk left somewhere ? ,or the nylon string piece found could there be more of that nylon wrapped around the shaft of the impeller ? once the shaft heat's up it would swell a tiny bit but i wonder if it's enough to compromise the tolerence's of the impeller assembly ? or if a piece of said nylon could have gotten wrapped around the water pump shaft. i'm no mechanic just trying to help.
Back to top
leokow
moderator
moderator


Joined: 12 Oct 2006
Posts: 415
Location: Osborn Island, NJ.(Little Egg Harbor)

PostPosted: Tue Nov 20, 2007 8:10 pm    Post subject: Reply with quote

Adrian, I can't believe the strainer hook-up, the purpose of it is to stop junk from getting into the pump , so mounting it after the pump doesn't really accomplish much. Also any junk that came from the pump should have been caught in the strainer, that's the only benefit of the set up you have , that I can see. John, you must have ESP , I couldn't see or figure what the hoses were connected to below the picture.
Yes, the boat ran perfectly before as far as I know. Adrian , you should stick with trying to find one problem at a time or you could get into a mess. Before you take it all apart , just try what I said with the strainer top, it just may need a new gasket.
Also , now that you've told us the way the system is hooked up it changes things a little bit.With the pump on the inlet side of the strainer it tells me the pump is what's losing prime, not the strainer having an air leak.
There's nothing between the pump and the hull except for the shut off cock , correct ?
Just a little shot at the electrical problem ,when we get the water problem settled we'll be glad to help with that.(I would definitely check out the cables before anything else.)Especially that fat one, that eagle eye John spotted !!
Back to top
View user's profile Send private message Send e-mail
rebait
moderator
moderator


Joined: 27 Oct 2006
Posts: 482
Location: Bayville, N.J.

PostPosted: Tue Nov 20, 2007 9:50 pm    Post subject: Reply with quote

I just did some research on the Volvo Penta site. Adrian, you posted in Introductions that the engine is a KAD 32 (Compressor After Cooled). The strainer is supposed to be mounted on the discharge side of the pump. It then feeds to the oil cooler. According to Volvo Penta's North America Site, The complete strainer, they call it a filter assy. along with the pump assy. and strainer screen is available from the dealer only. The pump overhaul kit is $150.00 and the cover is included. The parts for the strainer are: Cover $28.56, Seal $19.49, Pressure Plate $4.47. These parts are available from Volvo Penta direct. The phone # 1-800-916-1123.
I would go to the site and see if anthing is missing, such as the $4.47 pressure plate that fits below the lid on the cannister before going any further. Try to stay with Volvo Penta parts and try to return the other strainer. Log onto the European site and see if there is a number to call for help. I would call any number posted and maybe they can direct the call to someone who can help. Some parts guys are pretty good.

Guys, I think we have been looking at Crusader and Merccruiser systems too long. After looking at this system I will take ours any day.

Adrian, WE will solve this yet.

John
Back to top
View user's profile Send private message
rebait
moderator
moderator


Joined: 27 Oct 2006
Posts: 482
Location: Bayville, N.J.

PostPosted: Tue Nov 20, 2007 11:29 pm    Post subject: Reply with quote

Adrian,

The strainer on top of the pump, is that a Volvo Penta unit. Going back over your posts, I did not want to miss any facts, you said that you replaced the strainer. Was that a complete unit or the screen? If this is the original VP housing, there is the $4.47 pressure plate. When the plastic bag was sucked up was the pressure plate accidentally discarded? If so this may be the culprit and it is the cheap fix. If only we could be so lucky.

John
Back to top
View user's profile Send private message
rebait
moderator
moderator


Joined: 27 Oct 2006
Posts: 482
Location: Bayville, N.J.

PostPosted: Tue Nov 20, 2007 11:54 pm    Post subject: Reply with quote

Adrian,

My mind is racing a mile a minute on this problem, The first thing that I would do if the strainer is the correct Volvo Penta is to change the pressure plate and seal (you mentioned that you saw water dripping). These are low buck fixes. I am not sure what the function of the pressure plate is, whether it is to retard the flow from the pump or hold the pressure from backflow. If the pressure plate holds the water from flowing forward it would cause the pump to overheat. The next thing that I would do is to rebuild the pump or get a price on a new unit. This pump may have been cooked ("water hot enough to make tea"). After the problem is resolved, I would consider installing the strainer that you bought on the intake side of the pump to eliminate a potential problem like the plastic bag. I would install it with the top of the strainer at the water line with a seacock installed between the pickup and the strainer.Make sure all hoses are doubled clamped. I definitely would not install the second strainer until the overheating problem is solved completely, because this may compound the problem. Go with Volvo Penta parts after the pump.

John
Back to top
View user's profile Send private message
leokow
moderator
moderator


Joined: 12 Oct 2006
Posts: 415
Location: Osborn Island, NJ.(Little Egg Harbor)

PostPosted: Wed Nov 21, 2007 6:54 pm    Post subject: Reply with quote

So far I agree with everything that John has said. I still have one little problem, though. If the strainer is after the pump on the discharge side, then why isn't the pump holding prime even if the strainer is leaking ?
Could be that the pump is worn although not bad but just enough to let a little air bypass it and let the system drain out.
regardless, I would do the strainer fix first as it is the cheapest way to go , one by one it will get fixed ! I hate overheating problems !!!
Back to top
View user's profile Send private message Send e-mail
rebait
moderator
moderator


Joined: 27 Oct 2006
Posts: 482
Location: Bayville, N.J.

PostPosted: Thu Nov 22, 2007 12:09 am    Post subject: Reply with quote

I agree Leo, the pump should hold prime. There is a piece of this puzzle that is missing. I have never worked on a system like this. One theory that I have is that if the pressure plate is missing, the strainer drains out through the exhaust and becomes air bound. Thus the empty strainer and the pump gets hot. Adrian fills the strainer and eventually the air pocket is cleared. I am figuring this by looking at the pictures and the part catalog. Wish that I could see this in person or a tech manual. I just went back over the posts and I see that Adrian checked the pump with the top of the strainer off and he had a good flow of water. The more I think about it I am inclined to see about the pressure plate in the strainer.

John
Back to top
View user's profile Send private message
leokow
moderator
moderator


Joined: 12 Oct 2006
Posts: 415
Location: Osborn Island, NJ.(Little Egg Harbor)

PostPosted: Fri Nov 23, 2007 11:10 am    Post subject: Reply with quote

That sounds like a long way to drain the water,John, but with the strainer mounted where it is above everything else, it's entirely possible.
One of the things that gets me is , this engine ran fine in this configuration for a long time so I hate to change anything without finding out what went wrong with the original configuration first.
Volvo must have had some crazy reason to mount things the way they did, although for the life of me I can't figure out why.
I'd like to take that whole strainer assembly off, because that little hose between it and the pump would be hell to play with,swing it aside and crank the engine over a few times to see if the pump works and then stays filled with water when she is shut down. If he had an extra piece of hose he could connect it to the pump and aim it overboard or into a bucket , then pull the extra hose off and see if the pump is still full of water. This would isolate the pump from everything else and if it doesn't hold water then their must be some wear in the pump or another defect in it that's causing it to lose prime.It could even be what Terry suggested a little earlier, a small crack in the housing that closes up when she gets hot, that would answer the intermittent question. No matter what I try to figure out , I still come back to the pump, especially now that I know the strainer is on the discharge side of it. Plus I think a little ways back, Adrian said he found some debris in the strainer, whatever he found had to come from the pump or thru the pump before it got to the strainer,so here I am back to the pump again.
Once I got this system working properly again, I think I would seriously consider reversing this pump ,strainer situation,or add another strainer between the sea cock and the pump and leave the rest of the system alone.
Back to top
View user's profile Send private message Send e-mail
rebait
moderator
moderator


Joined: 27 Oct 2006
Posts: 482
Location: Bayville, N.J.

PostPosted: Tue Nov 27, 2007 12:08 am    Post subject: Reply with quote

Leo,

The pump should definitely be replaced or at the minimum overhauled completely with the correct Volvo Penta kit which includes the worn end plate. It is most logical that it would loose it's prime and drain back thru the impellers. Why a strainer was not installed on the intake side of the pump is beyond me. The pump should immediately regain it's prime and displace te air. Adrian should not have to keep filling the strainer. I would like to find out what the purpose of the pressure plate is and if Adrian's is bad or missing. Is the outdrive stored in the up position, and the pressure plate is bad or missing, does the water drain out from there and air enters the strainer from there. There is a missing piece to this picture. I just wish I could get my hands on this. The next evening that I am home at a reasonable time I am going to research Volvo Penta deeply and find out what I can. I don't know what we are missing. Personally I would have overhauled the pump and and replaced the cover, pressure plate, seals and screen in the strainer and INSTALLED AN ADDITIONAL STRAINER ON THE INTAKE SIDE OF THE PUMP. And if that did not solve the problem replace the pump and strainer with new units from Volvo.

John
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    Pacemaker Boats Forum Index -> Engines and drive train All times are GMT - 4 Hours
Goto page 1, 2, 3  Next
Page 1 of 3

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2002 phpBB Group
Effex-Media Web Resources
Create your own free forum now!
Terms of Service Purchase Ad Removal Forum Archive Report Abuse