Advice on oil leak(s) - PeachParts Mercedes-Benz Forum

cliffmac · #1 05-10-2009, 08:54 PM

Truth here...today I went to my local AutoZone to get a quart of Castrol 20-50 for my 1990 300TE. This thing leaks (does not burn) about 1 quart every 6 weeks or so. Anyway, when I came out of the store I noticed (which I didn't notice on the way in) there were 2 other hoods up in the parking lot under which the owner was adding oil. One was an S320 and the other a C280...I go and do the same to my 300TE and I wonder...do all these things leak oil? It was semi Twilight Zone-ish. Not only that, but we all looked at each other, made eye contact, and left. How much would
a front crankshaft seal replacement go for? Thanks

mbzman · #2 05-11-2009, 01:39 AM

More than likely the head or front timing chain gasket need replacement. The M103 and M104 engine are well known for their head gasket issues. Depending on how much oil you are losing, you can delay the repair of the head gasket, providing oil is not entering the coolant and you watch the oil level closely. Eventually, however, you will have no other choice but to get the gasket(s) replaced. Have you pinpointed the exact location of the leak?

hookedon210s · #3 05-11-2009, 02:18 AM

Probably a combination of upper timing cover, vc gasket, head gasket and VG oil seals. VG oil seals can account for quite a bit of oil consumption on that engine with no exhaust smoke or smell. A while ago I was burning/leaking 2 qts. every 1200K miles. After replacing the VG oil seals consumption/leakage is now 1 qt. every 1500K mkiles or so. Engine still leaks from head gasket at the right rear and I have the parts to repair but so far the burnt oil smell from oil leaking onto the hot exhaust mainfold is tolerable. Mark

tinypanzer · #4 05-11-2009, 07:48 PM

I was able to get away just doing my upper timing cover seal and valve cover seal. I also did the camshaft seal while I was at it.

It wasn't too hard a job..... Took me about 2 hours.... Once I had all the parts. Use the MB brand sealant goo, it's $25 but worth every penny.

I thought I had the typical M103 leaky head gasket, but it turned out that the oil from the timing seal and valve cover was migrating everywhere and in fact my head gasket was OK.

I'd start by doing those because you can knock it out yourself and it doesn't cost very much. You'll have to redo the upper timing seal again if you pull the head, but that's not so much wasted effort that it isn't worth trying first. I cut down my oil loss considerably, but I think I am still losing some to my valve stem seals.

cliffmac · #5 05-11-2009, 09:40 PM

thanks for the input guys. Another question...what is the encapsulation pan? thanks

ps2cho · #6 05-11-2009, 09:45 PM

Agreed. You can find out if the upper front timing cover gasket by cleaning the area under the distributor cap with brake cleaner, wiping it then watch and see if you can see oil dripping after a drive. Once it drips there -- it goes everywhere all over the engine. The gasket is a pretty easy fix -- Distributor cap + rotor off, then the chain cover and you are there. No need to remove anything else.

TMAllison · #7 05-11-2009, 09:50 PM

Quote:

Originally Posted by cliffmac

thanks for the input guys. Another question...what is the encapsulation pan? thanks

Belly/drip/sound/encapsulation pan.

Ferdman · #8 05-12-2009, 06:21 AM

The noise encapsulation pan is underneath the engine, held on with 4 or 6 bolts depending on the style pan. If you bought your car used the pan may be missing.

tinypanzer · #9 05-13-2009, 02:51 PM

Quote:

Originally Posted by ps2cho

Agreed. You can find out if the upper front timing cover gasket by cleaning the area under the distributor cap with brake cleaner, wiping it then watch and see if you can see oil dripping after a drive. Once it drips there -- it goes everywhere all over the engine. The gasket is a pretty easy fix -- Distributor cap + rotor off, then the chain cover and you are there. No need to remove anything else.

Almost - you have to do the valve cover as well....... You also have to remove the camshaft adapter which will have a tendency to break. And you might as well do the camshaft seal while you're in there.....

cliffmac · #10 05-13-2009, 08:14 PM

so my oil leak could be from the cam shaft seal? I had the same thing on a 1983 BMW 633CSi...when I took the distributor cap off it was filled with oil. I couldn't believe the car would still run....I replaced the seal as part of a general tune up and never thought about it again....hmmm....that makes sense......thanks

tinypanzer · #11 05-13-2009, 10:09 PM

I wasn't saying that it was your leak spot, just that if you are going to tear the top timing cover off, you might as well replace that seal while you are in there........

brewtoo · #12 06-21-2009, 11:23 PM

Quote:

Originally Posted by cliffmac

so my oil leak could be from the cam shaft seal? I had the same thing on a 1983 BMW 633CSi...when I took the distributor cap off it was filled with oil. I couldn't believe the car would still run....I replaced the seal as part of a general tune up and never thought about it again....hmmm....that makes sense......thanks

Your leak is extremely likely to be the seal under the upper timing cover. Do a search and you will find tons of information about this well-known issue.

Also, you could find the following DIY under the resources tab right up at the top of the page:

http://www.peachparts.com/Wikka/M103TimingCoverReseal