ON a hot day (85C) and the air conditioning on the car shakes. The coolant temp is about 90C and everything else looks good. Any suggestions.

Thanks Derick

Be more specific.. is it like a rough idle? Is it only worse with the AC on?

Car shaking
 

It's a rough idle and it get's worse when the AC is on.

Thanks Derick

Ok, a rough idle could be caused by many things... lets go over the basics.
When last were the spark plugs and the plug wires changed?
Are you using quality gas, and 92? Try a bottle of TECHRON in the fuel system.
When last was the fuel filter changed? This caused a rough idle for me.
What about your air filter?
These are the common, more likely reasons for a rough idle.
But if you would tell your model car, year and mileage, it'll help us out further to assess what else could be your problem. GOod luck.

Car shaking
 

My appologies - it's a 1987 300TD with 171K miles.


Thanks Derick

Car shaking
 

Engine mounts are the original. It's my wife car and I have not experienced the shaking personally. I have driven it a few times and once with a Mercedes technician but could not duplicate. She swears it vibrates on a hot day and AC is on.


Thanks Derick