W210 Oil Leaks
 

98 E320 4Matic Wagon 100K miles...

I (and my indy mechanic) have been chasing oil leaks. There is an engine oil leak from the left (driver's side) front of the engine. Oil runs down and drips off the left front corner of the oil pan when the car is at rest. And the trans pan is leaking. So far we seem to be throwing parts at it. Replaced so far:
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O-rings behind the oil filter housing where it attaches to the timing chain cover near the oil pressure sending unit.

Oil filter cap.

Transmission pan gasket.
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I am stumped about the engine oil leak and am tired of throwing part$ at it. My question: is this a common leak "area" and what part commonly leaks from this corner of the engine?

My indy mechanic says about the continued trans pan leak: the pan itself could be warped :rolleyes: and we might need to replace the entire pan. I'm no MB expert but a warped pan seems a little far fetched to me. The mech says he's seen it before but I'm beginning to think he botched the gasket replacement... Or maybe never did it in the first place...

Any suggestions from this gallery? Thanks
-Mike

The P/S pump could be leaking. When it does, it drips down on oil pan and a/c compressor. Front crank seal
could be leaking, oil will drip off where you stated. I would suggest putting UV dye in the oil and then testing a few hundered miles later with UV light.
You should be able to get the "Tracerlite Leakfinder kit" at any auto tool
vendor for around $60. The trans pan could be bashed from any number of
reasons. The gasket could be pinched or cheap, The tech may have been a bonehead and screwed up, or the Trans electrical connector could be leaking and oozing down on the pan gasket area. You can diagnose trans leak with uv dye as well.
Regards,
Dr.D

Thanks Dr. D. That makes sense about the engine oil leak.

I've been under the car and there is no damage to the trans pan. It looks like new but still is dripping (slowly) from the corners. I'm suspecting the gasket was pinched... bummer! Now I have to convince the mech that he needs to re-do the gasket replacement.

finding leak
 

If you don't have access to the UV dye & light Dr D recommended then clean all the oil off that section of the engine transmission. Start it up and let it run to see if you can see the fresh leak.

Clean the area, then spray powder in the area(spray foot powder works great).

Then drive until some OIL appears again, you should be able to see exactly where the oil is comming from!

Hi Aviaator -
The trans leak on that car most often comes from the connector housing on the right front side of the trans. The plastic housing and o-rings are easily replaced, have changed several million of them, myself. ( IT feels like that many, anyway.)
Also, on the engine oil leak, did the harmonic balancer ( front crankshaft pulley ) ever come apart and damage the front cover / oil pan ?
If not, the other place to check is the oil pressure test cover on the front of the engine cover just to the left of the oil filter housing. It has 2 bolts that hold it on, and has a round plug in the middle of it. The seal behind that cover leaks with age / mileage. Hope this helps.

...so that's what it called - "oil pressure test cover"! Thanks, Paul.

That's what appears to be leaking on my E320. Here's my recent thread about it.

http://www.peachparts.com/shopforum/tech-help/134529-98-e320-w210-m112-whats-leaking-pic.html

I haven't replaced it yet. I've been hoping to get some advice on replacing the gasket before I just try taking things apart. Do I need to drain the oil first? Do I just unscrew the torx screws, pull the cover off, replace the gasket and then screw the cover back on? Do I need to do anything with the plug?

Thanks for the detailed response Paul. The harmonic balancer has not come apart and the front cover/pan is not damaged. I'll print this and take it to my mechanic for his opinion (after I look in that area myself :) ) For the tranny connector housing: does the ATF need to be drained when replacing the o-rings? Or can the job be done w/o fluid pouring out all over the place?

MB Doc: great idea with the spray powder -- I'm gonna try that!

Update since going to the shop again today:

The mech agrees that the connector housing might be leaking but he says that to get to it you have to drop the pan... True/False?

Also, the PS pump appears to be the culprit of what I thought was leaking engine oil.

-Mike