I recently purchased a 1995 c220 that seems too be idling too high...........I am new to these and would appreciate some insight........the problem seees to be the majority of the time....it idles around 1500 rpm. Also it has a rattling noise that seems to be coming from the front of the engine under what i think would be the cam cover..........It has 204k on it, but has a new wiring harness and the idler pulley assembly was changed at 180k Any help would be greatly appreciated

 

Under your hood at the drivers side , Look for your actuator. At your actuator, under it near the throttle cable return spring, there's one vertical metal with screwed ends up and down. Unclipped this screw(you will here a snapping sound) from the actuator body and slack the upper screw, then turn the nop at the head of this metal in a clockwise direction to make a complete turn like about 2 times , tightened it back to the throttle body and test to see if you'l have the desired rpm reading of between 500 to 1000 rpm. Repeat the process until you are able to achieve that desired rpm reading . Note, clockwise turning reduces the rpm , but anticlockwise increases the rpm.

After wards you can also adjust the throttle body to achieve the desired leg pressure too. Note also that clockwise reduces but anticlockwise increases.

If after doing all these you have a rough idling , uninstall the actuator and clean the carbon deposit in and out of the actuator chamber before installing it back and repeat the same process all over again. cheers

 

THank you for tip....I did it this morning and it worked great...it settled right down and is idling smoothly at about 750 rpm. I ended up having to take about 4 rounds out of the shaft to get it right.....Thanks again

 

You are welcome! Congrats, i'm glad that your problem is solved. Enjoy your ride