300E Top Overhaul questions?

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.

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

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

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)

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.

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