Had my 1981 240D for just a little over a year. All this time I put up with some small leakage from the oil cap.

I think I bought 3 or 4 caps, in trying to stop this leak, and all were made in China. I tried once to take 1 cap and add two of those rubber gaskets. Too fat to tighten down.

So, I just wipped down the valve cover when ever I stop to buy Diesel. But Tuesday, there was engine oil everywhere !

At lunch I went to an auto store and just to look around to see if I could buy something but .......

On the way home, I ran into a new parts store, and asked for a oil cap. The clerk came out with a part made in Israel. It works. in fact I looks like the cap that was made just for a 240D.

I am so proud of this cap, I took a picture. My first time to post a picture, sure hope it works.

I was so down and out over this leaking oil cap, I wanted to sell.

Now, once again I am a proud owner of a 1981 240D 4 speed manual..

Bob

A leaking oil cap can be patched by coating the gasket with bearing grease.

Hi Bob,

what is the name of the parts store?

Probably 80 percent of oil caps on cars in the wrecking yards do not leak. You may even be able to look at the engine it is on and if dry get the cap. Make sure you breather line is clear. In fact even clean in out inside. The better it flows air the less pressure against the oil cap. That is the tube from on top of the valve cover to the breather area usually.

There is a seal underneath the cap that can dry up which causes a lot of leaking. Try replacing it. You can also bend the two tabs on each side of the cap a little so they hold the cap on tighter.

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AutoZone, the cap came in a white box. If not AutoZone, then Advance Auto.

Bob

Buy the proper cap from Mercedes, they don't leak.

http://catalog.worldpac.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=22Q1ED60H22U1EA5QX&year=1983&make=MB&model=240-D-002&category=All&part=Oil+Filler+Cap

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

It WILL leak, with time.

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'81 MB 300SD, '82 MB 300D Turbo (sold/RIP), '04 Lincoln Town Car Ultimate

Sooner or later every car falls apart, ours does it later!
-German Narrator in a MB Promotion Film about the then brand new W123.

Exactly, and it will be cheaper than going to Pep Boys five times.

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Kent Christensen
Albuquerque
'07 GL320CDI, '10 CL550. '01 Porsche Boxster
Two BMW motorcycles

Well going on four years now and I have yet to have one leak...besides they are cheap, if it leaks replace it.

If your engine has a ton of blow by it will leak a bit as I found out on my SD, nothing you can do about that. They are not ment to hold back a ton of blow by vapor.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

yea the bearing grease trick works.. I like it.. I would like a metal OEL cap though

The one I bought is metal, when on, the handle runs North/South and not like the brass one from China.

Bob 240d

The metal cap has a spring loaded tab that sandwiches the metal groove on the valve cover when you close it. This provides for a good seal if the cap is new. In time these springs weaken and no matter what rubber gasket you install, it will leak.

I don't know if the plastic ones are spring loaded, they seemed more firm to me.

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http://farm8.staticflickr.com/7271/7...144c3fc1dc.jpg

I do know they work themselves on their tight! Dear God I had to put everything I could muster twisting one off an M119 this morning. Their is no way that thing is leaking, almost need a wrench to remove it! They always get stuck on the gas engines for some reason.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Not as much blow by......

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Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John