TAMD41 losing coolant

[Reflection]

Hi all,
My port side engine has started losing coolant when driven hard, can cruise all day at 8kts with no problem but once I exceed 15-16 kts she starts to lose coolant, approx 1L over an hour running
-No evidence of water in oil
-No water being expelled from top of expansion tank, so don't think its head gasket. Also carried out a compression test a short while ago when refurbing injectors and all was good
-No water in gearbox oil
-No water in bilge

Exhaust manifold to turbo gasket is known to cause this problem but mine has earlier been replaced by the newer steel type which is supposed to solve this problem.
not seeing any evidence of rust runs down side of engine which I believe are a sign of leaky exhaust manifold gasket.

When I got the boat 18mths ago this engine had quite rusty water whilst starboard was clean coolant. At the time I flushed it out and added new coolant (Volvo) to both engines, both coolants still look nice and green.

Currently have main heat exchanger off being pressure tested but from some crude DIY testing I suspect it is OK.

Has anyone else had similar experience ?

Rgds
Richard

 

[Plum]

Hi all,
My port side engine has started losing coolant when driven hard, can cruise all day at 8kts with no problem but once I exceed 15-16 kts she starts to lose coolant, approx 1L over an hour running
-No evidence of water in oil
-No water being expelled from top of expansion tank, so don't think its head gasket. Also carried out a compression test a short while ago when refurbing injectors and all was good
-No water in gearbox oil
-No water in bilge

Exhaust manifold to turbo gasket is known to cause this problem but mine has earlier been replaced by the newer steel type which is supposed to solve this problem.
not seeing any evidence of rust runs down side of engine which I believe are a sign of leaky exhaust manifold gasket.

When I got the boat 18mths ago this engine had quite rusty water whilst starboard was clean coolant. At the time I flushed it out and added new coolant (Volvo) to both engines, both coolants still look nice and green.

Currently have main heat exchanger off being pressure tested but from some crude DIY testing I suspect it is OK.

Has anyone else had similar experience ?

Rgds
Richard

May I suggest you make a pressure tester, using some hose, a tyre valve, a pressure gauge and a bicycle pump, then before you refill with coolant pump up to 15psi. I connected to one of the 8mm bore vent hoses that fit to the header tank. With no coolant you may just hear a leak that is out of sight. Then repeat with coolant which will show a visible leak. This will not find every possibility but will certainly eliminate a lot and is quick and easy. See this picture https://drive.google.com/file/d/0B2pXHbT6ZkK0cHdHYl9pMjVSaG8/view?usp=drivesdk

Www.solocoastalsailing.co.uk

 

[Sailorsam101]

I had just this on an AD41..was the fresh water pump that was leaking badly. hard to spot but a simple fix with a reconditioned pump for Volvo paul.

 

[Mr Googler]

Put in some coolant uv dye....go for a run then shine a small uv torch around the engine.

I tracked a leak this way from exhaust manifold which ran along the top of the block, down the back of the engine, hit the bell housing and went both sides. All very confusing! One exhaust manifold bolt was loose....nipped up....problem solved!

 

[Reflection]

Hi guys,
Many tks for all the pointers so-far, food for thought and something to keep me "out of mischief" at the weekend......
Just one thing I'd like to clarify, I may not have been 100% clear in OP.
I am pretty certain that I am not losing the coolant through any leak outside of the engine, ie there is no coolant gathering in the bilge(it's a clean bilge, so even a small leak I think would gather there and be visible)
Notwithstanding the above, all suggestions are welcome, I will take a closer look around the block in case I am missing a small trickle somewhere.
Rgds
Richard

 

[Plum]

Hi guys,
Many tks for all the pointers so-far, food for thought and something to keep me "out of mischief" at the weekend......
Just one thing I'd like to clarify, I may not have been 100% clear in OP.
I am pretty certain that I am not losing the coolant through any leak outside of the engine, ie there is no coolant gathering in the bilge(it's a clean bilge, so even a small leak I think would gather there and be visible)
Notwithstanding the above, all suggestions are welcome, I will take a closer look around the block in case I am missing a small trickle somewhere.
Rgds
Richard

Bear in mind that if you are only losing coolant when very hot and under pressure it may be escaping as steam so very difficult to see until it condenses or if it ends up passing through the engine and out of the exhaust.

www.solocoastalsailing.co.uk

 

[Reflection]

2nd update, just got result of heat exchanger testing back. Tested from both sides up to 45psi both hot and cold and zero leak apparent.
Looks like the search will have to continue......