Leak at Oil Pan Gasket / 6-71

[spartonboat1]

I have an oil leak on one of my J&T 6-71N's, which I noticed in the Spring of 2012 . Over an 8 hour run, I went through about 5, maybe 6 qts. I did notice interestingly, that when the oil got down about 2-3 qts, that the engine starting running a tad warm. Once topped up, they cooled back down.

THis is on my stbd 6-71N is my re-build engine, with about 400 hrs on the re-build. However, she was overheated about 10 years ago for 2-3 minutes, but the head pulled and the condition reviewed by a surveyor and an experience engine tech; they gave a clean bill of health.

I tried to observer where the leak was occurring and it seemed to be at the seam of where the oil pan gasket fits between the pan and engine. There was a steady seepage below the gasket, but did not seem to be above the gasket.

I know that pan gaskets can leak on automobile with high miles, so it is possible on a 6-71?

P.s., I searched the forum first, but found no discussion of this there.

 

[Fanfare]

Tighten the bolts and see if it stops. Sometimes the sheet metal pans can get rust holes in them and leak. They are thin and not readily visible so they don't get painted enough.

 

[MikeP]

If it's a sheet metal pan and it is leaking at the pan gasket, it won't hurt to try and tighten it at this point but I'd be willing to bet that's not the issue and that tightening won't help. Typically, sheet metal pans get warped at the bolt hole area due to over tightening and they will never seal after that. IMO the bite-the-bullet method is the best way - remove the pan, true up the mating surfaces and reinstall with a new gasket, being careful not to over tighten the bolts.

If you cannot remove the pan completely due to clearance issues then I'd suggest the shadetree method...drop the pan as far as it will go, clean off the old gasket, put a 1/8" thick bead of silicone around the entire mating surface, let it skin over - maybe 20 minutes - then reattach the pan with the bolts finger tight using a socket without the ratchet. Then, maybe an hour later, snug up the bolts with a small ratchet. I use a 1/4" drive ratchet/socket for such work because it makes it much harder to over-tighten or break/strip a bolt. If you are anal you can use a small torque wrench and torque to specs.

Waiting the 20 minutes/ one hour will eliminate "gluing" the pan to the block. If you don't care if the pan gets semi-permanently attached to the block, put the 1/8" bead on the pan and immediately tighten the bolts with the ratchet.

Running the oil normally at the "add" mark on the dipstick will also usually help reduce the leakage I would not expect that to cause the engine to run any warmer but if you experienced that with your engines than go with what works for YOUR engines. I have always run my 8V71TIs at the "add" level - they use less oil when doing that which is quite common for many "old technology" engines, gas or diesel.

Good Luck!

 

[Fanfare]

When I put my new engines in 20 years ago I put epoxy coatings on the pans and the lower part of the transmissions. Seemed to make sense while they were in reach.