Oil leaking from valve cover breather...

[SynPDX]

Curious if anyone here knows where I can start in the troubleshooting process.

I have oil leaking from the breather elbow. It's not much, but enough to cause concern.

This is not a PCV valve....

Thanks ahead of time!

 

[saltydogjeff]

Re: Oil leaking from valve cover breather...

Did you check your oil levels and if there was any signs of water/coolant in your oil? Such as frothy white/milky white.

Edit: Also, what type of engine, year, s/n.

 

[SynPDX]

Re: Oil leaking from valve cover breather...

Did you check your oil levels and if there was any signs of water/coolant in your oil? Such as frothy white/milky white.

Edit: Also, what type of engine, year, s/n.

Yeah, engine oil looks good. It's level is perfect, and oil looks healthy.

Engine is a 1998 Mercruiser 3.0 Serial 0L066610

 

[makonnen]

Re: Oil leaking from valve cover breather...

Check for excessive blow by... ie: combustion pressure leaking past the rings into the cylinder block and coming out of the valve cover / breather elbow.

Always start your diagnosis with the easy stuff:

Open the oil filler on the valve cover, start the engine, hold a tissue paper over the oil filler, check for blow by at various RPM's.

When you're ready, you can go deeper with a cylinder balance test (also easy), compression and leakdown test. I wouldn't trust the result of any one of those tests ... have to analyze the results of all three tests.