H 34 OIL LEAK, When motoring for 4 hours or so I find a small puddle of oil under the engine! We have replaced all the Crush washers in the oil piping, replaced the fuel pump gasket, oil filter, pan gasket, valve cover gasket, and it seems that there is a linkage bracket coming out of the block just above the injection pump replaced that o ring but it still seems to be leaking somewhere! and now were at a dead end with this one! Help!!
oil leak H34
- Thread starter hunter healer
- Start date
Possibly rear main seal. Put your hand under the oil pan and see if you find oil on the bottom. If leak is small you can just keep an eye on it indefinitely. Wipe it up from the sump before leaving in the morning and as long as it is just a few drops motor away. Check the oil every so often and fill as necessary.
Clean up the pan and engine a best you can, then place white oil pads or even paper towels under the engine. When the first drip shows up you should have a pretty good idea where it's coming from. Rear main is likely, can't see it and hard to get to. Front main would be pretty obvious. Valve covers will leak a surprising amount of oil and if the leak is in the back you won't see it. Look at the top of the bell housing and back of the block for signs. That would be the easiest one to fix. Sometimes just a turn on the bolts will do it.
Thinking you have a Yanmar 3GMF? Another place is the front gear case gasket. Several folks have reported a leaking gasket at he lower side of the joint where the front gear case meets the block.. (Below and a little starboard of the front main seal.)
Like Claude says: The timing gear cover gasket is prone to failing eventually. I replaced mine last year myself. It required about $40.00 worth of parts and about 4 hours of my labor. But the fix is better than new. After cleaning the front of the engine, look for seepage where the front cover interfaces with the front of the engine block. In my case, the oil leaked down and ran under the oil pan to the back, then dripped off and ran back forward to pool by the structural beam.
I've posted a picture of where to look as well as the procedure to change the gasket (.pdf file). That was for a 3GMF engine, but all the parts and procedures are exactly the same if anyone has the same failure on a 2 GMF model.
