Oil leak. Help with location

Just wondering if someone can help me identify the location of this leak by a photo. Trying to figure out if it’s coming from the oil pan or above, possibly from the timing case. And what could possibly be done about it without replacing seals.

It’s a Yanmar 3GM30 3-cylinder diesel. This is taken from the front.

I have never seen a Yanmar tractor.


It’s actually out of a boat. But same engine, just marinized. I just don’t have alot of engine experience. Hoping someone with years of looking at engine leaks can make an educated guess based on the oil patterns in the photo. :wink:

Then looking at the image?

It looks like the oil pan gasket is leaking.


First thing you do is make sure none of the bolts are loose

They were easier to turn than I would have thought. Couldn’t get a torque in. But the manual says 9lbs. So they aren’t super tight to begin with. I gave the front about an 1/8th turn. And leased up as I moved towards the back. Well see.

It’s possible they were easy to turn not necessarily because the bolts were loose or had backed off, but perhaps because the pan gasket has compressed and won’t seal anymore. Is it a cork pan gasket?

If the gasket is hard as a rock, then I wouldn’t expect it to seal well, even if the bolts are properly torqued

how old is this engine?

Is it a fairly rapid leak, when the engine is running?

Is the engine going to flunk some kind of official inspection, if it’s not 100% sealed up?

If you need to replace that pan gasket, will it even be possible, short of removing the engine?

1 Like