[W126 Coupe] This one's for Gerry.

[Carl Hansen]

Gerry,

The reason I didn't mention the valve stem seals is because there is indeed a compression issue. 155 in seven cyls. and 95 in one. The valve stem seals are not going to cure that problem. Also it's not a given that valve guides become worn just because the seals are leaking. what often happens is that in extremely hot temps or if an engine has been overheating and it's old chances are that rubber seals have dried out and cracked. With the excess oil passing through the valve guides there's a chance that they gum up slowing the valve action causing the valve to burn or at the very least develop a leak resulting in a low compression reading. The possibilities are endless. In any event the heads will have to come off.

I agree with you otherwise but you forgot to mention that if the cylinder heads are refurbished your compression will increase and the engine is really going to burn oil. In my early days as a mechanic I've done what you are suggesting but in every case increased oil consumption was the result. In my experience never overhaul the heads without at least honing the cylinders and replace the rings.

If you do the leak test I prescriped you will at least know exactly where the problem is.  

I see an engine comming out for an overhaul.

Carl
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.pairlist.net/pipermail/mbcoupes/attachments/20090715/c3fe021c/attachment.html>