the car is an 84 300sd with 206k miles. every once in a while i get a good engine shaking motion at idle. at operating temperature. can go weeks with the thing not shaking. then every once in a while the thing really, really shakes. only while ideling. have gentley pressed on the accelerator with the brake on and in drive and the shaking goes away when i release accelerator pedal. my question - is this the classic adjust/replace my rack damper bolt? my fuel filters are new. but to be complete my fuel may be 6 months old. or older. thank you.

Sounds like the rack damper pin to me. I'm assuming the shakes come after something like a highway drive. If you've never adjusted it before it's shockingly easy. I would pull it out and take a look at if first to see if you need a new one. If the tip seems springy it's probably OK. I would imagine it would be obvious if you need a new one.

I'd never driven an MB before I bought my car and I was shocked at the difference that adjusting the pin made. For me, the shakes went away and my low rpm power really increased. My girlfriend said it was like driving a different car after that!

I understand the newer pins are gold in color. I have one of the older silver ones and I guess they typically don't last as long. Still works, though, so I'm not complaining.

One sifference between my symptoms and yours, though, is that the shakes wouldn't just go away after I touched the pedal. They would disappear while I gave it a little juice but I think they would return after that. But at the next stoplight, sometimes it would shake and sometimes not.

I guess if the pin doesn't do the trick for you the old fuel might be the problem?

__________________
Ralph

1985 300D Turbo, CA model
248,650 miles and counting...

yes.

__________________
'82 300SD - 361K mi - "Blue"

"Good judgement comes from experience. Experience comes from bad judgement."

listen, look, .........and duck.

gentlemen, thank you both.