Potebtial leak? And whats the strange goo i keep finding...

[Terra-Loon]

For some reason, there is always a quantity of water in the base of my engine cavity. I dried out the engine cavity completely in March and fitted an automatic bilge pump which is doing it's job and I manually pump out whats left.

When I take her out, running the engine sparingly as I do, the water returns. So i am assuming it's not just rainwater getting in through one or two small cracks around some of the stanchion bases.

My boat is a Dehler Optima 98 and has a sail drive, there's never any moisture around the various skin fittings and my deck drains work fine. There is always a bit of water around the Sail drive diaphragm though.

Also, the water contains a large amount of brown goo that has a diesel smell about it, I've wondered if it's diesel bug? I've had a bit of trouble with it in the past but a cap of Grotamar works wonders there. Any ideas what the goo is?

 

[photodog]

Its probably coolant spilling out of the expansion tube... Mine does it all the time..

But mine is greeney..

 

[noelex]

Diesel bug is seen in the fuel filter not in water in the bilge.
You need to find where the water/oil/fuel is coming from.
Mop up all the water and put paper towels around the possible entry points. Gradually you can isolate the problem.

 

[Seajet]

How old is the engine ?

In 1988 I had a boat with a 1981 Volvo saildrive, one of the engine block core plugs rusted through and split creating a slight coolant leak - naturally at the worst possible place, the top of the Alderney Race in a calm, so we spinned / span along waiting for the Plan B araldite to set, a bit trying on the nerves I felt...

 

[ksutton]

A small (or even large) hair line crack in the exhaust silencer will put water into the boat.
It can be below the water lock running level so may not put exhaust smells into the boat.
The water if its from a crack in the silencer will be very hot and most will evaporate rapidly, leaving a high salty solution with other chemical traces.

Use talcum powder sprinkled around sail drive, engine area and exhaust to try and home in on the source of water.

 

[ex-Gladys]

A basic question, is it fresh or salt?

I had a fresh water coolant leak that took ages to find, as it was only apparent from the calorifier hoses when you bent them, but when hot the water came out quick...

 

[Tintin]

+1 for talc or other powder

 

[eastlaked]

Check the raw water cooling pump telltale. When the lip seals wear, water comes out of a hole in the pump body. Took me ages to find. My tip is to use one of those big torches, which illuminates the engine compartment like daylight, then you can see properly.

 

[MoodySabre]

The goo sounds like it could be emulsified oil - oil and water that have been mixed well when hot. I'd check the dip stick to ensure that there is no water in the oil. If there isn't then trace the leak as above. If there is then I'd be thinking cylinder head gasket and excess oil/water mix coming out of the dipstick hole.

 

[Terra-Loon]

Thanks for all the answers.

The engine is a circa '81 Volvo Penta MD11.

I have noticed some odd behaviour with my temperature gauge, rising quickly to hot then dropping as quick - this seems to be linked to the engine revs...

There's no sign of water in the oil and nothing leaking from the dipstick hole.

Re photdog, the liquid I'm finding does have a green tinge, suspicion pointing strongly toward a coolant leak.