I replaced the valve covers and cam sensor o-ring. Turned out cam sensor I replaced did NOT have an o-ring from factory. I'm starting to believe it's rear main seal but you see the leak at the bottom corner end. It keeps reappearing after I wipe it down. Any help on this is greatly appreciated. It's producing a very small drop of oil in the garage but I'd like to find the leak.

 

You can take off the bellhousing blank plate that's on the side opposite the starter and look up inside the bellhousing behind the flywheel with an inspection mirror and flashlight. You can easily see if you have oil dripping from the RMS this way.

Just make sure the engine isn't running

EDIT: These engines were designed so the starter can be installed on either side of the engine, there's a blank plate on the side that doesn't have the starter.

 

I was worried about taking off that plate. Ok will do.

Edit: and report back.

 

I removed the inspection cover “surprised it’s that open to the elements with one screw holding it in place” and saw some oil behind it near the bottom area of the plate about a cm in height. I didn’t see any oil on the flywheel. I guess my rear main seal is the culprit. 😒

edit: other than an oem half moon rear main seal gasket and rubber gasket “black”, is there anything else I should replace while I’m in that area?

 

The oil went about that high when I pulled off the plate. So there should be no oil in there at all. Uuugh

 

Just for fun poke around with the inspection mirror on the back of the engine to inspect for any leaks from the cam sensors or the valve cover that might be leaking down the back of the block. Your culprit is probably the rear main seal though, they only last about 150k or so.

 

Finishing up my engine install and noticed I was missing that plate cover, $81 on Z1 😭.

 

Could grab one at the junkyard for super cheap.

 

Unfortunately they want to sell it as a whole upper oil pan.