I had valve guides and seals replaced on my '91 300SE at 90,000 miles.
Now, 30,000 later, it is using oil again (about a quart per 1,000
miles). My new mechanic (I've moved to a different state) tells me
that he thinks that the valve guides and seals need replacement, and
that 5 of the spark plugs had oil on them. He suspects that the first
mechanic may have charged me for valve guides but only replaced the
I suggested that the next time I bring it in, that we replace the
seals and see if that works. He said that he didn't think that would
work, but he would be willing to try unless the valves have just too
much play in them. If that is the case, he would proceed with the
valve guide job. He also said that he normally does not replace seals
without doing the guides too.
Does it make sense to try just seals?
Is there a standard for valve-to-valve guide clearance? Is it
measured or just an acquired "feel"?
On Tue, 22 Jul 2003 13:41:11 GMT, email@example.com (Richard J. Sexton
(At work)) wrote:
Not really. It used almost no oil for about 15,000, then started
using again - not gradually, but as if someone had turned on a switch.
It did get worse over time, but for the most part, it started all at
I take it that you concur that the first mechanic didn't replace the
Figures. I think I can trust this guy, but then again I thought I
could trust the first guys too.
Have you seen these (I'm not pugging them), just for interest.
I'm going to have the head done on my 110 engined 123.
All the reports from friends who have used them on classic cars are
very positive. They seem to offer superior performance to the original
The 'rifling' effect on the insides seems to help with oil retention,
but not allowing it to pass down into the cylinders.
I'm getting hold of a spare 110 head, and I'll have these fitted, then
swap the head.
I guess they're available in the USA. Maybe worth asking your local
engine re-conditioner about, to see if he has an opinion.
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