Hello,

I continue to have an oil leak (dripping off the bellhousing) after doing the following:

1. replaced rear main seal 3 times (along with oil pan gasket)
2. replaced valve cover and valve cover gasket
3. replaced o-rings on oil filter adapter

I have read many forums on all of these procedures plus the Haynes manual and have followed everything to a T, including when/where to use RTV sealer and proper torque specs. There is no oil running down from the valve cover or oil filter adapter. There are only 3 possibilities that I can think of as to what is still causing this leak.

1. I have only run the engine for about 20 minutes in between changing each rear main seal, as I figured it would seal immediately, however, I recently saw in a post that it may take a couple days of driving for the seal to swell. Has anyone had any experiences like that?

2. The third time I replaced the rear main seal I noticed the oil pan gasket did not fit snug against the main bearing cap, even with the bolt holes lined up properly. This seems odd to me. I checked the gasket to see if it was the right one, and it is. Has anyone else noticed this? Is it normal?

3. I noticed a slight groove in the crankshaft. I can just barely feel it with my fingernail. The engine has 185k miles. I know that can cause a leak, but I didn't see any oil on the flywheel side of the bearing cap. This leads me to believe that the rear main seal is okay.

If anyone has had any similar experiences or can think of any other possible sources of the oil leak that would cause it to drip out of the bellhousing, please let me know. Because at this point, I am about to pull the engine and do a rebuild.

Thanks

 

Could be the the oil galley plug on the back of block. Unlikely but possible.

 

check the distributor there is a small gasket at the base where it goes into the block

 

oil pressure sending unit? I thought mine was leaking from the rear main seal but turned out to be the oil pressure sending unit.

 

I had the same problem with my 99....i changed the oild pressure sending unit that solved the problem they are about 27.00 and very sensitive u probably hit it when u change the oild filter i mean they are senditive check if it is wet and that could be ur problem

 

When you did the rear main seal did you use the anaerobic gasket maker??? When I did mine the first time it leaked worse than before I replaced it.

I did it a second time with the anaerobic stuff, let it cure overnight, and the leak was fixed

 

I was going to say this one too.

 

I used permatex ultra blue RTV gasket maker. I will check all other places that were suggested, but I am still concerned about the oil pan gasket being loose around the rear bearing cap. That just doesn't seem right to me.

 

I don't know the exact name so this will sound fuzzy, but did you reinstall that curved metal piece that connects from one bolt hole to the other on each side of the rear bearing cap? The bolts go through holes on each end and it helps hold the pan against the cap. I can imagine someone accidentally losing or tossing it aside and forgetting it.

 

I'm going with the OPS. Very easy to smack it with a wrench on the 4.0L

 

Yes, I did reinstall that brace. It does go on the outside of the oil pan correct?

 

Outside, correct.

 

As last resort add engine dye-run till leaks and use black light with googles to detect. Could be rear of intake leaking.

 

Have the same problem. I actually put another engine in it with 70,000 miles and still having a problem

 

I put a newer engine in it with 70,000 miles and about a week later its still leaking. 3 new rear main seals, new oil pan and gaskets. Im stumped