water in the engine bay

[blue-max]

Coming back  to  the boat after a time away I usually find  fresh  water standing under the sump. Last time I was away for 4 weeks there were 2 buckets worth. This has been going on for some time. There was a leak from the calorifier  but that's been  fixed. The engine was also loosing coolant but no apparent anti-freeze could be detected in the water. There had been a leak following reconditioning of the heat exchanger but the dodgy jubilee clips had been replaced.
I traced the source to faulty cockpit drain seals. There were lines of dirt deposits on the rubber hose from the underside of the cockpit drain to the metal pipes from the skin fittings inside the engine room. Perhaps I should have dismantled the drain and resealed entirely  but lacked time and knowledge on the installation  so  I just applied new sealant between the drain and the teak cockpit sole. Hopefully  that will work. Still don't know why I am loosing engine coolant - no obvious leaks  any ideas 

[IslandAlchemy]

If you are losing coolant and it's not appearing in the bilges, then it is going out of the exhaust, which usually means a failed head gasket.

[Yngmar]

If the drains on the 47 Ocean are the same as on the 40 Ocean, you can just remove the jubilee clip at the top, unscrew the screws holding the fitting down and pry the fitting out. Then install with new sealant. Ours leaked when we bought the boat the same way and never since I did this.

[JEN-et-ROSS]

If you are losing coolant and it's not appearing in the bilges, then it is going out of the exhaust, which usually means a failed head gasket.

This could indeed happen..
But, since the pressure in the water jacket is going to be about 10psi, and the pressure in the cylinder during compression and power stroke higher by a colossal margin, this pressure gradient is more likely to squirt combustion gasses into the water-jacket rather than the other way round...
This would result in high pressure in the coolant circuit, causing coolant to vent into the bilge where its colour would make it easy to identify.......

[blue-max]

Thanks Jen - That's a comfort - don't want to have to  change the head gasket. I suppose I could do  a compression test to see if there is an issue. I was hoping I might have air in the system which iis slowly venting out.

[JEN-et-ROSS]

Hi Blue-max....
If the coolant level's dropping over time with no sign of a leak, then it's more likely a duff pressure cap (radiator cap thingy) and the loss is simply slow evaporation of the coolant...... Hope it helps....

[Krumelur]

You might be looking at two separate issues?

As far as the fresh water under the engine is concerned: on my 40 I found the source of leaks being the metal inlays in the cockpit where the the lock mechanism of the companion doors is located. See photo. I had to remove and reseal them.

[blue-max]

unlikely to be pressure cap as I replaced this when the heat exchanger was overhauled. -- with the correct volvo part.

[Archer]

We went through a similar exercise last year and found the hinges for the companion way doors were also leaking fresh water into the the engine bay.

[blue-max]

I have a plan to replace the companionway  hatch (single perspex sheet) with doors so  will pay attention to  the seals. However, I have never noticed  any water seeping through  the current component but I suppose it only takes a little   at  a time  for the water to  accumulate. I can hope that the repair to  the cockpit drains has solved the problem. I now have an App to  monitor my bilge for water level - provided gratis from the marina management!