Mercruiser 5.7L Major Oil Leak Underneath

[Sundancer$]

2 Pints per hour oil leak on 5.7L into bilge. Only leaks when boat driven; when stationary no leakage; with engine removed no leakage on test bench. Installed in Sundancer 240 cannot trace even with mirrors and video. Help!

 

[Scott Danforth]

first, welcome aboard

next, common places to leak oil are rusted thru oil pans and front engine covers. both require the motor to be pulled

another less common is a bad oil sender (on block, behind intake on left side of motor, and a bad oil filter seal.

 

[stresspoint]

I'm in for a look here.

? how did you test motor out and running.
was it under load when the oil was leaking ?

rear main seal, dipstick tube cracked , intake manifold seals.
there are are plenty of places where that much oil could expel

 

[Scott06]

Do you have blow by on engine that may induce leaking from crank seals under load and not show when idling on the ground?

First thought is rear main seal or core plug in back of block where cam goes

Where was the oil on the engine when it was removed?