671 gray marine detriot deisel

This is a silly question, however, I'll ask it anyhow. I have developed an oil leak. Question is,what is the most likely culprit? Or should I say where? Don't know much about this engine. Hoping there is a particular place a leak may occur. Thanks for your help, and forgive my ignorance.

 

All you can do is to clean the engine as well as youn can.

Wipe with a rag with diesel , or kerosene if the diesel will smell too much.

Then keep looking , as diesel lube oil is usually Very black , it is EZ to spot.

What info source are you using to maintain the engine?

Do you understand only 40 wt CF II style oil can be used?

 

Yes oil type is very very very important

 

check crankcase breather vents also. if they get plugged, they'll push oil out of openings.

 

Speaking of crankcase, I install a system on mine the sucks the gases back into intake, like a pvc valve would, this reduced my leakage problems.

 

Common Detroit leaks: valve cover, rear main seal, front seal, tack drive.
Most Detroit engines have a pan underneath. High hour engines needing overhaul can create enough blow by/crankcase pressure to blow out seals and gaskets. If you're getting a lot of oil mist in the engine room, it's probably time for new sleeves and pistons.