Oil leaking from transmission cover?

[GNbythebay]

I have e a small engine leak and I can not locate where it is coming from. I brake cleaned everything clean to see where the leak is coming from and it is dripping off the transmission cover plate. I know it's oil and probably leaking down to land I that transmission plate but what could be leaking near that area? I took a picture hope it helps.View attachment 301757 View attachment 301758

 

[josh young]

Could be rear main seal, oil pan gasket, valve cover gasket, intake gasket, or pcv valve. Can you see any leaks higher up on the engine?

 

[GNbythebay]

Could be rear main seal, oil pan gasket, valve cover gasket, intake gasket, or pcv valve. Can you see any leaks higher up on the engine?

I checked and the valve cover pcv and intake gaskets don't seem to be leaking I also don't believe it is the oil pan so I think I will change the rear main seal. Is that a hard process to do?

 

[Nick Micale]

.............so I think I will change the rear main seal. Is that a hard process to do?

Every few months I have a customer that has a leaking rear main seal which, he or a shop, has "diagnosed" this issue?

I pull the converter cover and see NO trace of oil on the front side of the flexplate streaming out from the crankshaft to prove there no leak.

The most current customer brought in his 7000 mile GNX a couple months ago wanting to replace the rear main seal as an incompetent local shop told him it needed to be replaced.

After checking the "alleged" leak, my remedy which solved his issue, was to dump the Mobile 1 oil, and replace it with Valvoline VR1, and he drove it home with no oil leak since.

Having serviced thousands of turbo Buicks over the years, only one had a rear main seal replaced here!

 

[josh young]

Every few months I have a customer that has a leaking rear main seal which, he or a shop, has "diagnosed" this issue?

I pull the converter cover and see NO trace of oil on the front side of the flexplate streaming out from the crankshaft to prove there no leak.

The most current customer brought in his 7000 mile GNX a couple months ago wanting to replace the rear main seal as an incompetent local shop told him it needed to be replaced.

After checking the "alleged" leak, my remedy which solved his issue, was to dump the Mobile 1 oil, and replace it with Valvoline VR1, and he drove it home with no oil leak since.

Having serviced thousands of turbo Buicks over the years, only one had a rear main seal replaced here!

Nick from your experience what is the most common source of leak that winds up on the cover hole?

 

[Nick Micale]

A common area is up front as the turbo drain line or return line, the oil filter as well as the pump cover and, of course, the pan gaskets are all suspect. Valve cover oil leaks usually end up in the converter cover.

When the car is driven, oil is blown backwards and will collect in the converter cover, and drips from the hole in the bottom.

Clean the engine and area, then start the engine and look for drips. Easy on a lift, but jack stands will do also!