Hi all,

I just did front differential oil change and found a bad oil leak at the rear end of the engine on the driver side. . It's definitely not oil filter as front of the engine is 100% dry.

I tried to figure out where it's coming from by starting the engine and revving it but no cigar. I checked all fluids and only the engine is low, so 99% it's engine oil (and I know how my engine oil looks like and smells).

Car has 150k miles on it. Pictures attached.

Any help is appreciated.

It looks like it's coming from the same spot as in this topic: https://g35driver.com/forums/engine-...ing-death.html

But OP from there never came back with his resolution.

First step is to completely clean up any oil residue, use a rag on a stick, mop it up REALLY REALLY good, then start the engine and use a flashlight and inspection mirror (one of those telescoping mirrors on a stick) to probe around and find EXACTLY where the oil is seeping from. With that much leakage it shouldn't take long.

Be careful not to get your inspection mirror eaten by the drive belt...

Well, I hope that drive belt won't be an issue as front of the engine is 100% dry.

So far for having 150k miles car. Compression rod, wheel bearing, now this. I could be on my way to a new car.

Does it look like rear main seal?

I'm more inclined to suspect a leaky valve cover but rear main seals do fail so... If you open theaccess window at the bottom of the block (very middle bottom) that is for accessing the flywheel/flex plate bolts you could poke an inspection mirror in there and visually check for a leaky rear main. It's a tight fit but it will be obvious if it's leaking since you're looking straight up where it would be leaking from.

EDIT: It's really hard to tell from your pictures because literally everything is covered in oil at this point.

Yeah. Although it's definitely coming from the driver side/rear of the engine. I will give it a shot. I hope it's valve cover, not RMS, i'd rather fix it and install plenum on my own then drop $$$$ to a shop to install 30$ gasket .

You can put some dye in and with a uv light see if you can track down the leak.

This is happening to my whip now 06" G35x with 120k, its my Valve cover gasket is shot. Replacing it and new Plugs nextweek. GET IT FIXED BRO!!

I think its your valve cover gasket. When you get it fixed or fix it yourself check that the spark plug tubes are free of oil. You're already in there might as well fix that too.

Any updates on this thread?? I'm having the same issue with my 03 coupe. Did you find a fix for this issue??? My valve cover gaskets have been replaced , no oil leaks seen from this area.

Discovered oil dipstick was not inserted all the way no more oil leaks!! Thanks

Did you end up finding where the leak is? I just got this leak on my 2004 G35 Sedan and I'm scared to let her go because of it. did my valve covers and gaskets and may have to recheck them but if it's the rear main seal I'm screwed.


leaking on the backside/motormount

entire angle

on A/C compressor so it's from above

Check your engine oil dipstick. Check if it is seated correctly. That was my oil leak issue, oil was found in the same areas, identical to the images you uploaded.. Lastly, look over the seal on your engine oil dipstick. The seal will deteriorate over time, and you may need a replacement. I hope this helps.

I'm just confused because the (oil) doesn't have a scent and if so, I might just buy one to see. It could be the dipstick as I check my oil frequently.

I recommend de-greasing and cleaning your engine. It will be much easier to identify the source of your oil leak with a clean engine.