300E: Can you tell ... is this a head gasket - PeachParts Mercedes-Benz Forum

haasman · #1 01-01-2003, 11:47 PM

.... or front cover leak?

haasman · #2 01-01-2003, 11:51 PM

Another shot

Mike Murrell · #3 01-02-2003, 12:28 AM

I too have a 103 motor and saw the same thing in the same spot as you've just shown. Resealing the front cover did the trick.

103 head gaskets leak from the rear(passenger side) and when they do, you'll see oil on the ground just below that general area.

pmizell · #4 01-02-2003, 01:53 AM

That looks like your front cover is leaking. See the oil near where the heater return pipe screw is? That seems to indicate the oil is seeping from front cover (either a leaking cam seal, or the U gasket needs replacement). I'd replace both just to be safe --- pretty easy and quick DIY job.

G'luck!

maximus · #5 01-02-2003, 08:34 AM

Your oil leak looks identical to mine haasman. I actually thought it was the lower timing chain cover,then after cleaning the oil out and checking it after a few miles of driving I saw the oil coming from the exact location as it is on your pic.Since Mike mentioned that it is an easy job I want to go ahead and do mine but I know there isnt a gasket there so what did you use to seal that and what do i have to look out for to do the job right thanks
Also i know there is a gasket between the upper and lower cover is that the one u referring to.Let me know please.

Mike Richards · #6 01-02-2003, 10:15 AM

There are numerous articles here about replacing the infamous "U-Gasket" as some call it.

The official MB task number on the CD-Rom is 01-212 - Removing and installing top front cover.

This also requires that you get the serpentine belt off and that requires 2 special tools or some fabrication/ingenuity on your part. Performance Products sells both and I suspect this site may as well.

The following thread contains some good advise from Larry Bible and another poster further down gives the sealant number. You can get it at your MB dealer. I would describe the task your about to do to the MB parts counter person because there are many different sealants mentioned in the MB repair manual(s).

M103 - Upper Timing Chain Cover and Cam Seal Leaks

haasman · #7 01-02-2003, 10:36 AM

Thank you for the replies.

It seems the group all concurs that it is the front cover. Mike is forwarding the repair process. Is there anything tricky about this repair? How long should it take?

Haasman

#8 01-02-2003, 11:23 AM

Hi there,

Just did the top, timing chain cover seal on my 103. Not a big deal.

Removed the fan shroud
Remove plug wires
Remove valve cover
distributor cap
rotor
bolts retaining the cover
water return pipe located directly under the distributor (it's bolted to block, did not see bolt and bent pipe trying to pull it off).
pull off cover and replace all the related seals.

Note: Will need new water return pipe seal (black rubber seal).
I performed tune up at same time, no sense in putting old rotor and cap back on. Only factory recommended sealant should be used for back corners of seal (timing cover lip seal). Can purchase on this website (I did).

Whole job can easily be done in an afternoon.

Good luck,
Joel

PS> Does look like timing cover leak, I also noted that my alternator was covered in oil from leak.

Kestas · #9 01-02-2003, 12:50 PM

The procedure calls for sealant when replacing the upper timing cover gasket (U-gasket). Can any hi-temp rtv be used for this application?

#10 01-03-2003, 07:53 AM

Hi,

Here is the thread with the sealant part number, it's made by loctite and I would not use anything else. Would not want to redo job.

Hope this helps,
Joel

Loctite 5900

Kestas · #11 01-03-2003, 08:35 AM

Thanks Joel....read through the thread.....now everything's clear.

Followup question: Is sealant applied over the rear o-ring of the timing cover, the water passage that mates with the head gasket? When I took it apart, it looked like sealant was put there.

Buciraco · #12 01-03-2003, 09:04 AM

I use loctite 515 gasket replacer, very good

sixto · #13 01-03-2003, 06:09 PM

Quote:

Originally posted by 1992300e
Only factory recommended sealant should be used for back corners of seal (timing cover lip seal). Can purchase on this website (I did).

Joel,

Is the sealant listed in FastLane or did you go through PartsShop?

Thanks,
Sixto
91 300SE
87 300SDL
83 300SD

#14 01-08-2003, 08:15 AM

REgarding the sealant, call phil at fastlane, he'll hook you up.

I only applied to back corners of lip seal. I think the o-ring seal you are referring to is the one that is in the cover and slides over the shaft which the rotor bolts into. I did not apply sealant, should not think it's required. You may want to replace that seal.

Good luck,
Joel

Kestas · #15 01-08-2003, 09:35 AM

Quote:

Originally posted by 1992300e
I only applied to back corners of lip seal. I think the o-ring seal you are referring to is the one that is in the cover and slides over the shaft which the rotor bolts into. I did not apply sealant, should not think it's required. You may want to replace that seal.

Interesting... the manual instructs the person to apply sealant on the upper surface of the U-shaped seal. I found sealant on both sides of the seal in my car.

The o-ring seal I mentioned is on the upper timing cover and does not go over a shaft. The passage has only coolant. This too had sealant over the o-ring. I need to know if this is normal for assembly, or if some mechanic wanted to "make sure" there would be no leaks.

I've decided to replace ALL seals I disturbed. I want to make sure the repair is "better" than new. I have all winter to do this.