1982 Mercedes Benz

arakali_v

I have 1982 Mercedes Benz 300SD Turbo automatic transmission. The car runs smoothly. But after it warms up the car shakes when I stop at traffic light. When I shift to neutral the vibration is reduced. The vibrations increases when AC is turned on. Any one has any suggestion to fix the problem

burdawg

I'm not a diesel expert, but it sounds like the idle control isn't working properly, or the idle is set to low.

Mr_Shiftright

Possibly, but probably the idle is only the symptom, not the disease.

I would say you have one or more bad injectors that are "spitting" at idle, that is, sending an uneven or erratic spray. You might try a heavy-duty injector cleaner (from a repair shop, not something off the self at Grand Auto)....something really NASTY that you wouldn't dare touch much less spill on the car. Along with that HD cleaner, I'd add a fuel conditioner and also service all your filters if you have not done so.

If none of this works, it's injector time I think. DO NOT attempt to adjust the idle by turning screws this way and that. You could upset the entire injection pump timing.