2008kenw211

Hello,
Sometimes while in Park or Neutral my car will rev up to 2,000rpm and drop back down below 1,000.

It does it when both when I press on the pedal and even when i don’t.

I don’t think it’s an issue with the throttle body because I installed a new one recently, im thinking about going to a Mercedes dealer and getting it diagnosed there unless anyone on here knows what could be the issue.

Im guessing it could be the pedal position sensor itself.

thank you.

CaliBenzDriver

The engine computer needs to be trained to use your new throttle body. This is done using MB Xentry....

I think replacing TB contributes this additional issue. Original problem maybe: air bypass, MAF, ...

Recommend scanning the car for live faults before TB pushes ECU into limp-mode.

Throttle command has safety considerations.

2008kenw211

Thank you,

where do you recommend purchasing this MB Xentry?

CaliBenzDriver

The answer would be @BenzNinja with acclaimed remote service... so I hear

taylor210

Recently removed TB out from w210 and w211 to clean out all the gunks around the TB plate turning it manually by hand.( goes only one way). All cleaned nice and installed back, turned the engine the rpm jumped up n down too much.

Shut off the engine. Turn the key to #2 position(do not start)

Open the hood, put your ear close to TB, wait about 30 sec then you’ll hear click click sound from the TB plate. Ecu resets the TB, now start the car and rpm will be smooth as silk

Just try it, you’ll feel better

2008kenw211

I’ve tried this multiple times at it has done nothing to fix my issue.

e350forme

how about the press pedal down for 10 seconds and let the throttle body open and close it self/reset

2008kenw211

when I do this with the key in the second position it causes the ESP inoperative message to appear on the gage cluster screen

e350forme

esp messages (that I have had) are caused by a bad reluctor ring on an axle and then ABS /ESP turns off. does your power stearing get stiff?

e350forme

have you had the car smoked to check for vacuum leaks also, it could explain the idle issue

these are all basic things that any mechanic can help you with like pulling axle or attaching a smoke machine with a vacuum

2008kenw211

only time the steering was still was during the winter but only when the car was cold