jkowtko

Pulled the bottom covers off today to change out the steering rack bushings, and look what I found

• 115k miles. Changed oil last at 112k. Just added a half qt last month. Using Mobil1 Formula M 5w40 from the dealership.
• This is engine oil, not tranny fluid
• The oil appears to come from the front black plastic TC access plug
• No oil on the front side of the sump ... only the back
• A dried puddle of oil in the rear engine cover.

It doesn't look like an emergency situation, but I've never had any wetness there before.

What do you think? Is this the rear main seal? I can't think of anything else it could be.

I will monitor this periodically to look for more discharge. If the wetness continues, then at the next oil change should I consider switching to Pennzoil?

VVF

Kind of weird how it comes from the access plug and travels to the front...
Did you remove the plug to confirm it's coming from there?

Maybe vacuum pump?

jkowtko

Vacuum pump was replaced ~90k so I wasn't thinking of suspecting. I'll wipe back there again just to make sure.

No I didn't remove the plug ... I didn't want to take the time to figure out how to remove it without breaking it. I'll definitely have to do that for the next oil change.

There is no oil anywhere else I could see above or around that area. It just seems like a very slow seepage. I know, oil traveling forwards seems odd. however the engine covers must shield the underside from airflow, so this could be just a leeching action or turbulent backflow in that little space.

The last time I had the covers off was Feb 1, almost six months ago. It was dry and clean then.

Question on these types of leaks -- do they happen in bursts? Something I do momentarily -- like downshift to high rpms, or taking a heavy load -- that pushes a bunch of oil past the seal, and then afterwards it stops?

LexBenz

I have the same situation. Two weeks ago, I cleaned the cover at the bottom of my engine while the shop was replacing my chains, a/c comp, front cranks shaft seal, etc. Then last Saturday, I took my car to the dealer for "free check up", they said my car's rear main seal is leaking. So I called my independent shop and yesterday about it so they checked and found out that the cover is damp with oil. The indie shop tech said it could be from vacuum pump residue that was replaced 1k miles ago. Then later he confirmed it is the rear main seal. He quoted me $950 to replace my rear main seal, transmission output shaft seal, transmission front pump seal and torque converter seal which is a good price in my opinion. So tomorrow my car will be in the shop again. But I know after this, my car will be free of oil leaks.