Valve tappet tightening (M103) HELP PLEASE!
 

Hey guys, does anyone know how to tighten the valve tappets on an M103 (300e)? I thought there would just be a tightening nut on the top but there isn't it's just covered with a solid piece. I think mine are loose... I'm getting a lot of racket from under the valve cover whenever it's idling but not while driving (above 1100rpms or so). It's not a deep knock like a bearing, and yet not a super light tapping, kinda inbetween the two.

If anyone could help me on this I would really appreciate it!!

On the M103, the tappets are hydraulic self adjusting.

damn... i see. i wonder what is causing all the racket then.. :mad: its only at idle too..

Under where you thought the adjuster would be (under the "solid" piece) is the hydraulic compensator, this operates like a lifter in a pushrod engine, and it can wear out, just like a lifter can collapse, so can this .
Or there is another possiblity. Between the compensators and the valve stems there is a small cup-shaped spacer, this I have seen flip out from between there somehow and will make alot of lifter-type noises.

Gilly

probably just a bad lifter

very helpful info.. thanks Gilly!

No sweat. I'll also mention that the adjustment is possible 2 ways:
The "solid piece" you saw probably had what looks like a hole in the middle, this is actually just an ID mark, they come with "no" dot (thinnest), 1 dot (most common, next size up), 2 dots and 3 dots, I think that's it. OR the cup shaped washer is available in 2 different thicknesses, I think the thin one is most common, no ID marks on those that I'm aware of.
You'll have to pull the valve cover to search for the loose one, you may have to rotate the engine over a few times to find it, if the valve is pressed down you won't find it.

Gilly

Don't rule out the bushings on the belt tensioner shock. When they go the sound is very similar to what was described.

how is your oil pressure at idle?

oil pressure is a bit low at idle when it's warm.. usually on 2... sometimes a little below that.

Thanks for this piece of info as well.. I will certainly factor this in since I am not sure where the pinpointed problem is. I'm afraid I may end up just taking it to a shop to have the problem checked out and fixed.

For diagnosing noise sources it's hard to beat a cheap stethoscope, available at an auto parts store for about $10.