'82 240d shakes at idle in gear
 

While my 190d has been in the shop having new spring perches welded in I have been driving a friends 1982 240d. He's been calling it "The Third World Taxi" because it shakes like crazy in gear, it has few comfort features, but it runs great and gets you where you need to go.
I've been trying to work on the shakes at idle in gear issue while I've got it. It's got just under 150,000 on the clock. In gear with you foot on the break it shakes like crazy, but if you pop it in N or P the idle speeds up a bit, the oil pressure rises a bit and the engine smoothes out. As soon as you give it a bit of throttle it's smooth and has plenty of pep. Is this normal at all? Could this be related to any transmission adjustment issues?
I've played with bringing up the idle speed a bit and gotten it a little smother but she's starting to creep a bit too much with your foot off the break, especially in reverse.

el motor mounts

Have to just go down the list it could be....

Air filter
Fuel filter
Injectors
Fuel pressure relief valve
Primer pump
Clogged tank screen
Valve adjustment
Motor mounts
Transmission mount
Throttle pivot bushing

With the age and milage it can be anyone or combination of three or more....

My money is on motor mounts.

I had the identical symptoms in my 1978 300D. New motor mounts solved the problem

there is also a throttle shock on some 240's, the rack dampener bolt may be an issue, but not sure on that vehicle. remember, the 240 has 4 motor mounts, and sometimes there is an engine shock.
it's most often the driver's side motor mount though.

I'll check out the motor mounts. I don't think it has a rack damper bolt, or its not in the spot it is on my '85 300d. I'm not sure about the throttle shock, its an automatic transmission. Thanks all!

I don't know what a throttle shock is, but the 240D, at least mine, only has two motor mounts.

My 1987 190d has a throttle shock, it's a factory 5 speed. When the shock went it was very jumpy and sensitive as hell to small pedal movements at low speeds. It felt like a whiplash machine! I'll check on how many mounts are in this '82.

What is a throttle shock? :confused:

My 240D is an '82 as well!

It's a damper on the IP linkage to prevent bucking and jerking with a manual transmission.

nope.
if you look under the oil pan, there is another motor mount connecting it to the crossmember. also, the transmission mount is considered a motor mount, making it 4 mounts that can cause issues on a 240.:D

I didn't check under the oil pan or the transmission mount (my ramps are at the 240 owners place! :)) The passenger side mount looks totally trashed. The drivers side looks OK, but should probably be replaced anyway.
Thanks all!

I didn't see anyone mention motor mounts, so I'm going to go out on a limb and say this may be an issue.

The 300D don't have a transmission mount? I have replaced that. Never replaced the crossmember mount, never seen it either.