Oil leaking from oil cap - PeachParts Mercedes-Benz Forum

J.J. · #1 10-20-2005, 10:06 PM

After changing the oil and filter in my 1985 MB 300TD (172,000 miles) I cleaned the area immediately around the cap. Its usually caked with oil. The next day I noticed a slight amount of fresh oil leaked out from the cap.

The same thing is happening to my 1983 MB 300D (352,000 miles).

The oil caps don't look worn out and one looks brand new.

I use Delvac 1 and B100 but it appears the issue existed with the PO too.

Is this normal?

JJ

pawoSD · #2 10-20-2005, 10:43 PM

No that is not normal, neither of ours leak. You could try getting a couple new caps, or maybe your crankcase pressure is high, is the vent tube working ok/unplugged? Generally there is no pressure on the cap, so I would wonder why it would leak....I'd just guess a worn out cap. I used to have a metal one, but the stealer lost it so they gave me a new style one. Neither leaked though....

Ether · #3 10-20-2005, 10:43 PM

Don't know if it's normal but my 80 300SD does it.

I replaced my cap a few years ago because I noticed some leakage. The new cap leaked as much if not more than the old one so I just decided to wipe it off every few weeks and not worry about it.

techguy512 · #4 10-20-2005, 11:03 PM

Is it possible that you turned the cap upside down during
the oil change?

If you did, oil runs into the area of the cap above the seal and then leaks out when the cap is installed right-side up. The solution is to never turn the cap upside down.

Phil · #5 10-21-2005, 12:24 AM

Take the cap off and remove the rubber seal ring then clean out the cap and the rubber ring. Put the rubber ring in other side up and put it back on the valve cover. Thats what worked for me.