Logo
FULL SITE MENU

Mercruiser 7.4 Oil Dump

S

setilma

New member
I have twin 7.4's with just under 900 hours. They run flawlessly. After a trip in August, approx 45 min run @ 3400 RPM's, the port engine had dumped 2-3 quarts of oil into the bilge. i refilled the oil and haven't lost any since. How is this possible??? Where do i begin looking for a problem?
 
Ayuh,...... Look at the evidence, 'n follow the oil trail,....

Where ever you find the wettest spot, move up from there, til there's no more oil,.....
At that point, look slightly lower to where the oil starts,.....

A digital camera will fit in places yer head won't, which makes one handy for findin' yer leak,.....
 
I'd start with a compression test on both engines. My suspicion is that you may have some blowby happening under continuous high speed. I'd look at your PCV system to see if it's leaking, especially at the valve cover. Anyway, the engine that is running well should be your control engine, and you can compare the leaker to it. My guess is that the leaker is lower than the good engine.
 
Back
Top