Caterpillar oil leak up on top

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RickyD

Guru
Joined
May 4, 2018
Messages
729
Location
United States
Vessel Name
Aquarius
Vessel Make
Californian 55 CPMY
I have Cat 3208s. My Stb engine is a Cat long block replacement with 230 hours on it. Oil is appearing in the valley between the two sides. No problem on the port engine. This oil was there when I purchased the boat. It did not rise to the level of dripping into the bilge so I just figured I'd look into it later. So I'm now looking into it. Where might this be coming from?
 
Wipe it up and watch it. Find the source.
 
Clean the engine up. Maybe put some dye in the engine oil and use a black light to see where it starts appearing.
 
I have a pair of 3160s that accrue a trace that puddles in the little recesses here andthere, valve covers etc Never seems to run off. My mech says they come from the crankcase breather, no issue, just wipe up occasionally.
 
I have a pair of 3160s that accrue a trace that puddles in the little recesses here andthere, valve covers etc Never seems to run off. My mech says they come from the crankcase breather, no issue, just wipe up occasionally.

I'll check for the crank case breather wherever that is. Maybe last oil change was an overload. No I didn't do it. Previous owner's guy. I am just about to do an oil change. I don't quite have 100 hours yet and I'm in no hurry to deal with all that oil, both coming our and going in. My leak is kind of the same with the oil pool not seemingly going or coming, just being. I'm getting ready to start taking stuff apart o I can see but lately I've just been using her.
 
It’s oil not diesel right? Sometimes you can get a leak from the injection pump that would pool in the valley.

The head gaskets I’ve had let loose typically made a mess on the outboard side of the heads, but that is just my experience and I hope to never be any expert on additional failure modes. Crank breather if it slobbers usually runs outside since it sits on the valve cover.

As already said, clean it up and trace it.
 
There are 3 (I think) short hoses on each crankcase breather assembly. Clean them up good, then wipe underneath after running the engine. You’ll probably find one or more of them weeping. The breather assembly itself might be leaking; I’ve rebuilt one of mine so far, not a big job, but one that pretty much requires 3 hands.
 
Check the aircleaner. To see if any part of it is saturated with oil
That's what is happening on my 3208. I believe it is happening from running at low speed
 

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