300E Top Overhaul questions?

There is this tapping noise coming from my engine. It is very noticable at idle. I use Mobile 1 for the oil. The car can be hard to start sometimes too. I have new plugs, distributer/rotor, wires, air filter, ect. The plugs seem to get dirty fast, with oil on them. The car doesn't burn any oil. When warmed up th emotor is a little rough at idle but runs good when opened up. Any suggestions would be greatly appreciated.-Charles-89

300E 130K
Reply to
Chuckyg
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Consider that the fuel injectors may be leaking at shut down due to fuel deposits and need to be cleaned. A couple of cans of fuel injector cleaner may cure that. There may even be a carbon build up on the back of a valve that prevents it from closing fully resulting in the tapping that you hear. That's the optimistic diagnosis.

The pessimistic diagnosis is that the valve guide seals are worn and are allowing oil to be sucked into the intake manifold. One valve guide may be loose in the head causing the tapping that you hear.

If you idle the engine when hot for say 3 to 5 minutes and then rev it up (in place) does it produce a blue cloud of oil smoke from the exhaust? If so the valve guide seals are probably worn out and ought to be replaced. An experienced M-B mechanic can do that job without removing the engine's cylinder head. However, a loose valve guide may require the head to be removed.

Reply to
T.G. Lambach

Thanks for the info Tom.....Do you or does anyone know what a ballpark price would be for a job like this? Im planning on keeping the caruntil it quits. Im in NJ.-Chuck

Reply to
Chuckyg

Don¹t know for a 300e but on my 95 c280 I just had the head gasket replaced and a top end overhaul. Total cost: $2400 in washington dc (the car has only

70k, and is in excellent condition hence it was worth) at a independent mechanic
Reply to
chris tonjes

I just had valve seals replaced on my 1987 300E at an independent Mercedes Benz shop here in Central California. Including new plugs a little over $400.00.

Someone earlier posted $400-600.

Pete Cowper (1987 300E)

Reply to
Pete Cowper

So is Bill Ditmer (In NJ) who can do a job like this, if that's what's needed. I'll guess $600 but HE'll quote it.

Reply to
T.G. Lambach

It could be the bushings are bad on the tensioner shock. Common problem.

Suggestion: buy a cheap stethoscope for about $10 and listen for the source of the tapping noise before investing in major work.

At 130K, if serviced properly, the guides should still be good. Seals may need replacing, but that should be evidenced by oil consumption and deposits on the plugs.

Joe

Reply to
Joe Rutledge

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