Bad Idle Fixed!!
Thread Starter
MBWorld Fanatic!
Joined: Jun 2003
Posts: 1,179
Likes: 4
Bad Idle Fixed!!
hey guys. I know some of the W140 6cyl guys have been complaining of the bad idle. Well today I decided to work on the benz. I wanted to see what differen type of true cold air intake systems I could run. I took off the huge intake airbox/plenum and once I got it off I had a good look at everything.
I realized that the throttle cable was loose, very loose. I usually had to put the gas pedal in a about 2 inches before i got any responce. so i tightened it up by simple twisting the hex shaped screw with my fingers and went back in the car to check a few times until it was just right. now the throttle body opens up just a 1/4 inch past the closed pedal position which is exactly where i wanted it.
wow car behaves totally different. for starters, the car used to rev at like 500-600rpm which was low but i never figured out why, i just thought thats how it was. now it idles at a much more natural 700-800rpm. revs much more smoothly and it idles as a mercedes should, perfectly smooth. I still need to replace the motor mounts but this solve alot of the little annoyances the failed mounts produced.
Also i switch out my 20w-50 with some 5w-30. MAN what a change. car revs like a bat out of hell. So much better than with the 20w-50. I'm definately glad i made the change.
Lesson learned: keep tight throttle cables properly tight (remember don't over tighten though, just enough so gas pedal engages just as you push it).
hope that helps.
I realized that the throttle cable was loose, very loose. I usually had to put the gas pedal in a about 2 inches before i got any responce. so i tightened it up by simple twisting the hex shaped screw with my fingers and went back in the car to check a few times until it was just right. now the throttle body opens up just a 1/4 inch past the closed pedal position which is exactly where i wanted it.
wow car behaves totally different. for starters, the car used to rev at like 500-600rpm which was low but i never figured out why, i just thought thats how it was. now it idles at a much more natural 700-800rpm. revs much more smoothly and it idles as a mercedes should, perfectly smooth. I still need to replace the motor mounts but this solve alot of the little annoyances the failed mounts produced.
Also i switch out my 20w-50 with some 5w-30. MAN what a change. car revs like a bat out of hell. So much better than with the 20w-50. I'm definately glad i made the change.
Lesson learned: keep tight throttle cables properly tight (remember don't over tighten though, just enough so gas pedal engages just as you push it).
hope that helps.
Member
Joined: Dec 2003
Posts: 109
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just to note - the V8s with electronic throttle - never never rev it from iside the engine bay - there are two sensors on the throttle, one by the foot, one in the engine bay. if the two get 'out of sync' it upsets the computer
but thats V8s...
but thats V8s...
Thread Starter
MBWorld Fanatic!
Joined: Jun 2003
Posts: 1,179
Likes: 4
6 cyl is definately alot more simple than that. also i shoudl note mine is a OBD1 300SE so its doesn't have nearly as complex a computer system. the upside to that, modifications REALLY make a difference.
