oil found in bilge

[Va Pensiero]

I just discovered oil located directly below the oil pan on my Pearson 30. unsure where it is coming from. Had a leak in the water pump and replaced after a season. Did this do anything to the pan and if so can I repair w/o pulling engine?

[hanleyclifford]

Water pump gaskets are among the usual suspects for oil leaks. Try cleaning the area thoroughly and then start the engine and watch for seepage around the bolts and mating surfaces.

[sastanley]

Va P..as Hanley noted, they can cause oil leaks..I lay down nice clean rags (like old t-shirts) underneath suspect parts to observe and catch oil drips to help diagnose issues. I had a leaky water pump too with relatively new gasket and bearings..no water, but it leaked oil onto the starboard aft motor mount.

BTW - I fixed my problem with a nice moyer 502 pump. Pricey, but I should not have to rebuild it in the foreseeable future!!

[hanleyclifford]

It is also possible that the inner seal is allowing oil to get out. Put a clean rag right under the weep hole and see what happens.

[JOHN COOKSON]

Easy Stuff First

You could always start by seeing if the bolts that hold the H2O pump on are tight.

TRUE GRIT

[Ajax]

If it's not the water pump, check the rear main seal between the engine and transmission.

[ndutton]

How much oil?? Few drips, small puddle or a pool?

[Oldlaxer1]

These are great to have on board. Cheap too.

https://www.newpig.com/pig-oil-only-absorbent-mat-tablet/p/TLS751?utm_campaign=email_page&utm_source=trnemail&utm_medium=email&utm_content=product_link

[Al Schober]

A few suspects..
The bolts that mount the water pump have crankcase oil on the threaded end, which will wick through the threads and try to escape at the heads of the bolts. The proper washers for this location are the flat copper ones - to try to make a seal. Split lockwashers will leak. Anyone ever go with studs in this location???
Oil seal in water pump - will leak oil from the pump's cavity drain.
A third suspect is the aft seal in the transmission where the output flange enters the transmission housing.
Finally, the bolts holding the seal plate to the aft end of the transmission also need those flat copper washers - same reason.
Hey, my truck doesn't leak oil onto the driveway. Our boat engines should be tidy too.. (grin).

[roadnsky]

Here's a document Don put out about finding possible oil leak sources...

[Va Pensiero]

oil leak

Thanks to all that replied. Off to investigate all suggestions.
John, Va Pensiero

[dew]

One more thought, had a similar issue leak was around the oil sensor gauge. Had a few parts there that came from a hardware store. I wanted to look lower then moved my eyes and hands up a little there it was. Was a hell of a lot easier to get to and fix than most leaks. I think the worse part was cleaning the bilge.
Good Luck

[hanleyclifford]

Another spot often overlooked is the lower accessory drive bolt where the gasket has to be trimmed for fit.

[HOTFLASH]

Copper washers

Al,

I get why to use flat washers for that purpose (post #9), but why copper, as opposed to brass or SS?

Mary

[hanleyclifford]

Al,

I get why to use flat washers for that purpose (post #9), but why copper, as opposed to brass or SS?

Mary

Copper deforms and conforms to the fastener and the hole thus making a good seal.