crackrx

I own a 87 E300, which I love. The only real problem I have with the car is that it rumbles violently when it idles for a period of time. If it has been idling like this for a while the acceleration sometimes is very bogged down. I am not sure what to try to fix this. I also noticed that the spark plugs in cylinders 1,2, and 4 are covered in gunk. I believe this is due to oil burning in the
combustion chamber due to warpage in the cylinder walls. Let me know if I am wrong, and what I should due to fix these problems.

cap'n jasper

Sounds like valve stem oil seals.
Do you have smoke from the exhaust when you rev it after idle or when changing down a gear on a long run?
How many miles?

crackrx

I get smoke from the exhaust if I haven't run the car for a while. The idling seems to be the worst after I drive long distances, but no smoke that I notice. The car has about 235,00 miles.

cap'n jasper

I'm pretty sure you can change the valve stem oil seals on the 300E without removing the head (1 - 1.5hrs work). If that doesn't do it then you're looking at a head rebuild ie..valve guides (head off = big bucks!).

crackrx

What tools do you think I will need for the job? Thanks for help.

cap'n jasper

I have to confess that I've not done the valve seals on a Merc. Your best bet is to take it to an independent Merc tech. I took a 190 in once and they changed them within the hour and charged me £60 ($100). It's not worth getting covered in oil for that!
With 235K miles it could well be worn valve guides but I'd change the valve stem seals first and see what happens.

bamberger_1

I guess you posted this thread also in "Tech Talk" find my answer there, which is pretty much in line what the other posters said.