Hey guys,

I need some advice/options. I have a persistent oil leak originating from the camshaft seal inside the timing chain cover/housing. Thus far, I have replaced the camshaft seal numerous times, I've installed a new timing chain cover/housing and I've replaced the valve cover gasket as well.

My mechanics have replaced the camshaft seal three times for me (last 2 times for free) but the leak persists. Over time, the oil will foul the distributor cap and rotor enough to cause a noticeable rough idle (the engine runs perfectly otherwise). I periodically remove the cap and clean the cap and rotor but this is obviously not a desirable remedy. There was also a leak coming from the timing chain cover where it mates to the engine block, along the lower part, but the new cover and some MB sealant cured that leak. The volume of oil lost has gone down dramatically since I fixed that, but some is still leaking via the camshaft seal.

I'm at a loss as to how to cure this problem. I'm guessing perhaps the camshaft itself has worn down such that it no longer fits the timing chain cover smoothly and no amount of new seals is going to stop the leak? The engine does have 300K on it and everything is original.

Short of buying a new camshaft (and hence probably rockers, etc. may as well do the entire head while I'm at it) is there anything I'm missing?

Any advice would be appreciated.

__________________
Chris
2007 E550 4Matic - 61,000 Km - Iridium Silver, black leather, Sport package, Premium 2 package
2007 GL450 4Matic - 62,000 Km - Obsidian Black Metallic, black leather, all options
1998 E430 - sold
1989 300E - 333,000 Km - sold
1977 280E - sold
1971 250 - retired

"And a frign hat. They gave me a hat at the annual benefits meeting. I said. how does this benefit me. I dont have anything from the company.. So they gave me a hat." - TheDon

Chris:

300K on the motor.....

Time for some work I suspect.

Not sure if the cam end rides in a journal type bearing? If so, some basic head work and a new cam might do the trick.

I think I'd give up on the fix it over and over thing and pull the head, then find a good machine shop and let them go over it.

My 2 cents.

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"

Chris,


I'd inspect the camshaft when replacing the seal- Look for a groove or obvious wear. I doubt that's your problem.
Review the installation proceedure in the manual carefully- perhaps you are not getting it installed straight(?). Not uncommon to re-seal the front cover- use the factory sealant stuff!


Michael

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Michael McGuire
83 300d
01 vw A4 TDI
66 Chevy Corsa
68 GMC V6 w/oD
86 300E

A light polishing of the cam surface that the seal rides on may help. Material to use is an extremely fine "crocus" cloth. It polishes more than cuts.
Hope this helps.

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Hanno
'79 6.9 Sold (after 27 years)
'83 280SL, 5 spd.
'94 E320 Sdn. 5 spd conversion
'02 E320 Sdn.(on loan to mom!)
'87 300E (5 spd. conversion) Sold
'05 E500 Wagon

On many cars, a common leak is the timing cover seal. This happens because the harmonic balancer sealing surface gets a groove worn into it that prevents a good seal. The cure is what is known as a "speedy sleeve." This is a very thin polished nickel sleeve that you press over the harmonic balancer sealing surface. It works very well.

If you get measurements, you might find the correct size speedy sleeve at an industrial supplier such as MSC.

Since the seal has been replaced multiple times I doubt that this could be the problem, but it is relatively easy for this seal to "fold under" when installing it. MB makes a special sleeve tool that can be used to slide the seal in place without it folding under. I don't own such a tool, but have had good success by simply running my fingernail around the seal as I push the cover rearward and just see that it does not fold.

Good luck,

There is a possibility with your mileage, that the overpressure from weak rings, etc could be all it takes to make that little seal leak (plus the wear groove in the cam certainly doesn't help). You can check this out by loosening your oil cap; if it wants to "blow off" when loose, then you have a possibility here. You can check your air filter return line and your valve cover to make sure there is no blockage, if this is the case.

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Don't ask me, I'm a shop-owner by default