VIOLENT Shake when in reverse
 

1983 240D Automatic, Lots of vibration & Shaking while in park and drive... but when put in reverse ARMAGEDDON breaks out.


I have owned 3 other Auto 240Ds, and they all had little to no vibrating while idling or while in any gear, one even ran and sounded like a new gasoline car. So I do have a base line of how these should run.

Motor mounts look new, I put on the new style bosh primer, all new filters, new return lines, fuel tank screen is spotless, no dry rotted fuel lines, new cigar hose... everything I can think of that would cause it to vibrate so violently but nothing has made ANY positive effect.


It runs a like a dream, starts on the first crank even in the cold, etc etc...
but the vibrations are KILLING me and annoying the crap out of my wife

Am I looking at a shot trans mount?

Are you sure it is running good
 

You say it runs good and starts good. Yet it sounds to me like it is running on three cylinders. Have you had the compression checked? Are your motor mount bolts tight? Is your front pulley and damper assembly turning smooth and true and pulling all the belts? If it shakes that bad, there has to be a reason and you better find it before something really lets go.

reverse puts strain on the rear trans mount. if it's shot, it'll make a ton of racket in reverse.
the rest of the vibration really sounds like compression or air in one of the injectors... perhaps not firing on one cylinder. I'd crack each line at idle and see if any of the injectors has no effect on the idle...

It could be an injector also
 

If you can keep it running at an idle speed running in reverse, you could block the rear wheels very well, (both front and rear),set the parking brake and while running loosen the hard fuel line at the top of the injector. If the engine runs worse when you loosen the first injector, (engine will probably stall) that one is not your problem. Go through all four injector lines. Did one not effect the running of the engine. That is the one that would be the problem.

While the Engine is idling loosen the Fuel Injection Line Nut a the Injector of number one and see what happens. Tighten it back up and do the same on down the line.

Doing this to the a problem Cylinder/Injector should not change things much. Thing should get noticeably worse if you do this to a good Cylinder/Injector.

If the above turns up nothing I would be taking a colser look at all of the Mounts including the Transmission Mount.
Also have you been under the Car to look at the Mounts while the Car is in reverse?
Have someone else sit in Drivers Seat whith their Foot on the Break and the Parking Break Set. Could block the wheels also if you wanted to.

trans mount can cause this. i've replaced alot of them for bad idle vibration in gear.

If the problem only occurs when in reverse then its unlikely to be fuel related. The back trans mount is a good place to start.