Bavaria 38 engine cooling problems

[stuartwineberg]

ViCS doesn't need my endorsement but the comment about a collapsed hose not seeming to be collapsed from the outside is important - it is usually a delamination as he says

I was think along the same lines as MASH a collapsed hose somewhere....... de-laminated so that it is obstructed internally without anything being obviously wrong from the outside. Not necessarily one of the inlet hoses.

Normal flow at idle but reduced flow at higher engine speeds is a symptom of a de-laminated hose.

 

[Playtime]

YBTW my anti-siphon valve is on the high pressure side of the water pump (between pump outlet and heat-exchanger) so I don't see how this could suck air in (unless somebody can explain). Actually a question to all - is that the right place for it?

Yes - as others have said.

I have just checked the photos of my previous engine and the anti syphon is indeed on the high pressure side of the pump, between the pump and the heat exchanger. I don't think it would work on the inlet side on thinking about it. Apologies for any confusion - old age dims the memory!

My problem with the anti syphon valve (and why I replaced it with the Vetus equivalent) was water leaking rather than air bleed. The air bleed was in the black Volvo seawater filter. I never could get a proper air tight seal with the lid.

 

[nigelmercier]

ViCS doesn't need my endorsement ...

I'm always pleased, and somewhat relieved, if VicS happens to agree with something I've said.

 

[Tranona]

That's interesting

On my 34

Pipe 1 runs from the seacock to the black filter
Pipe 2 runs from the filter to the pump inlet
Pipe 3 runs from the pump outlet to the syphon
Pipe 4 runs from the syphon to the heat exchanger.

Sorry forgot to add ... was going to suggest joining 1 to 2 to bypass the filter as a test.

Exactly the same set up as I described on my 37. Some engines - the Nanni in my other boat for example have a hose from the heat exchanger to the exhaust and the anti syphon goes in there. Functions in the same way.

 

[bluedragon]

I discovered that one of the copper pipes on my filter was badly corroded and had pin-holes. I made a replacement with some copper pipe and a solder fitting cut to length to provide the step.

Yes, mine are VERY green. Need to check that.

 

[29er]

I had the same problem on the D2 - 55 on my Dufour. Solved it by having the raw water inlet moved from the engine leg to the bottom of the boat (and blocking off the leg inlet) and never had another problem.

 

[iainbluk]

Thanks 29er for the info, I might have to do that in the end..but as it worked ok for 400 hours I ought to be able to sort the original design out I feel.

I had the same problem on the D2 - 55 on my Dufour. Solved it by having the raw water inlet moved from the engine leg to the bottom of the boat (and blocking off the leg inlet) and never had another problem.

 

[iainbluk]

Update on my cooling water problems:

Spent a day checking all the hoses and jubilee clips etc, and by a combination of reseating the hoses, retightening the clips, and greasing around the black rubber gasket on the filter basket, the air coming through the system seems to be reduced. There was a definite sign of air in the outlet out the filter before this work, it now seems to be gone. there is still a small amount of steam coming out at higher revs, but much less than before, and when the sea water warms up this may well go.

Thanks to all the forumites who have contributed to this thread.

 

[Friday Guy]

I have a 2003 B38 which I have owned from new but have recently had a problem with the salt water cooling side of my engine which is a Volvo D2-55. At idle revs it kicks out a decent ammount of water through the exhaust and all seems well. However as the boats speed and engine revs are increased the water being ejected from the exhaust progressively reduces and steam/water comes out of the exhaust. The engine is not overheating at this stage according to my temperature guage, but the exhaust seems to be. The steam is definately that, having smelt it, it is not unburnt fuel. There appears to be air getting into the system somewhere, as bubbles can be seen in the clear pipe that leads from the heat exchanger to the exhaust elbow. The exhaust elbow does not seem to be blocked as the pipe from the heat exchanger is not under pressure whilst the engine is running.

The engine has done about 550 hrs

So far I have
1) Replaced the impellor
2) Replaced the water pump seals
3) Replaced the seals on the bottom of the raw water filter pipe inlets
4) Replaced the filter basket and seal
5) checked the leg inlet is not blocked when it was lifted last week including rodding up the leg to remove any possible crustacean blockage.

Has anyone else had or heard of this problem? I am at a bit of a loss as to what to do next.

Thanks

SOLUTION / ANSWER TO PROBLEM FOUND:

I also had the same problem with my Bavaria (2005) with Volvo D2-55 engine. Engine exhaust contained an excessive amount of steam, and the engine sound from the exhaust port sounded "unmuffled".

If you see a large amount / larger column of bubbles in the water as it circulates this indicates an air leak in the system, more specifically, it indicates a leaking seal in the water pump allowing it to suck air. You will need to gauge between "normal" bubbles and an amount of bubbles that presents a condition that indicates an anomoly. I replaced the water pump with a new assembly from Volvo. Old pump unit exhibited at least one leak source. Once replaced, the exhaust from the engine returned to normal.

Note: Fix was proposed, and work completed by "Dean Marine" at Friday Harbor, WA. (360) 298-1116

Take care.