Oil leak '99 E320 M112 engine
 

I've noticed small amounts of oil underneath the engine of my wagon. Took it to my indie who couldn't confirm precisely where the leak was, but diagnosed that it was coming from the top-end and thought it was most likely coming from the valve cover gaskets and replaced both left and right side gaskets.
He also said that the alternator area was covered with oil and cleaned the part. He said there were also a couple of other seals which could be leaking.

A few weeks later during the Christmas holdays, I noticed oil on the ground. My indie was on vacation, but his son looked at the car. He put dye in the oil and with UV? light determined there was a leak at the oil level sender unit. I authorized the replacement of the unit even though it didn't match the earlier diagnosis of a top-end leak.

Sure enough I've recently noticed more oil leaking. I'm taking it back to the indie next week. Does anyone have any ideas or experience with common leaks on this engine?

The car has 200 kilometers. I've paid for two repairs without success.:(

Thanks
3star

The vent covers on top of the valve covers are frequent culprits - reseal with silicone sealer if he didn't already. Another common area is a small oil pressure port gasket on the front, behind the belt. The gasket is about $1 and an easy DIY.

There's a test port for checking oil pressure located on the timing chain cover which is a well known cause of oil leaks. It's located just below the filter housing, and resembles a torque converter drain plug. Since there's already UV dye in the oil have your guy inspect this area closely.

3star, once your indie finds the actual leak source I would seek a credit for the 2 previous repairs that didn't fix the leak.

Thanks guys. Hopefully I can at least get credit for the labor.

sorry to hear about your oil leak issues. You should have the whole top end engine and bottom end completely steam cleaned then re evaluate for leaks.

If the oil is on the ground it could be from the rear main seal. Look under the car at the bell housing area. All the other leaks usually are caught in the plastic cover under the engine. The rear mail seal on these cars do leak fairly frequently as they age.

was the seal in the test port for checking oil pressure located on the timing chain cover as suggested by ILUVMILS:)
Cheers
3star