Water in oil but no oil in water???

[arfaname]

Hi all,

Recently bought a boat with a so called "rebuilt engine". I have no proof of its rebuild. It all tested up ok.

I have just had the carbies rebuilt and got her running sweet but have now developed water in the oil. The engine is a sealed fresh water sytem cooled via a heat exchanger using raw water. the engine is a Volvo AQ170

1. The cooling system is not pressurising and is holding temp at about 75 deg c with clean water and coolant.

2. the raw water is flowing fine out of the exhaust and is relatively warm, perhaps 45deg c.

3. The engine runs an oil cooler on the raw water side.

4. The milky oil in the sump does not look green at all (like coolant) however I cant be certain.

I am not sure where to start.

Do I retorque the head and cycle the oil to rid the water?

Do I have the oil cooler pressure tested?

Do i remove the exhaust manifold and if so how do I check it?



What to do??


All help greatly appreciated..


Thanks

Sean

 

[jerryjerry05]

Re: Water in oil but no oil in water???

1st do a compression test.Check the plugs for water/rust.Then drain the antifreeze and pressure test the system.Check the oil cooler for leaks.
If that tests ok then remove the manifold and check the exhaust ports for rust.Then check for flow to see if it's blocked.Jerry

 

[Bondo]

Re: Water in oil but no oil in water???

Do I have the oil cooler pressure tested?

Ayuh,...

That's where I'd Start...

 

[wannabeamedic]

Re: Water in oil but no oil in water???

Had a chevy engine do the same thing, is it foamy or all gray liquid on the dipstick, if it is foamy i think that is moisture in the engine and rebuilds will do that cause of the bearing lube that is used if so change the oil. my .02

 

[45Auto]

Re: Water in oil but no oil in water???

Couple of things to think about. You may have more than one problem.

1) Is the fresh-water cooling system loosing water? If it's not, then the water in your engine IS NOT coming from that sytem. However, it should be pressurizing. You need to find out why it's not.

2) I don't think the absence of green color in the milky oil is any indication of where the leak is. I've never seen any kind of tint to the milky oil in a car (running green or orange antifreeze) with an internally leaking cooling system. Always been a gray milky mess.

3) If the fresh water system is loosing coolant, I would start looking there. If it's not, I would start with the oil cooler as Bondo says. But in either case, you need to find out why it's not pressurizing.

 

[arfaname]

Re: Water in oil but no oil in water???

Thanks for the replies fellas,

If the problem exists on the raw water side, shouldn't the fresh water side remain untouched ie: not pressurised?

 

[JustJason]

Re: Water in oil but no oil in water???

i'd drain the heat exchanger, if there's no oil in it, id start looking at the intake manifold first.

 

[bruceb58]

Re: Water in oil but no oil in water???

i'd drain the heat exchanger, if there's no oil in it, id start looking at the intake manifold first.

Intake manifold? On an AQ170? How would that cause water to get in the oil? Exhaust maybe.

 

[JustJason]

Re: Water in oil but no oil in water???

Intake manifold? On an AQ170? How would that cause water to get in the oil? Exhaust maybe.

Doh!!! your right... i posted that late. I wasn't looking and thought it was a 4.3 and not a straight 6. My Bad.
In the future... Everone just ignore me after 11pm