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1995 Mercedes-Benz S500 Question: car only runs rough while idle



shrubski, Dekalb, IL, May 15, 2009, 10:18

My 1995 S500 with 96000 miles runs rough while idle. While driving it seems to run fine. I have changed plugs,wires,rotors,dist. caps,coils,oxygen sensor and it still runs rough,can you help me,

3 Answers
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  • Medium-star Best Answer
    May 22, 2009, 14:59

    You could have a vacuum leak or a defective Air Flow Sensor. I would have the codes retrieved and properly diagnosed. Also have a compression test to verify that the cylinders are ok with good compression. If you can't find the vacuum leak , use a smoke machine to pin point the leak. This is a job for a Pro shop that Knows German cars.

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  • Reply

    Visitor, July 07, 2010, 11:22

    My s500 95 model with 76500 miles.The doors will not Vacum shut.When I remove the fuse & put it back,it works for a while & again it goes off.Can you advice????

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  • Answer #2

    Visitor, July 10, 2010, 10:21

    fuel preasure regulator

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  • Answer #3

    Visitor, August 04, 2010, 18:18

    I had this problem. It's your ETA, Electronic Throttle Actuator. You ASR light will eventually come and the car will go into limp home mode. Really sucks to have this problem. It's also a very expensive problem to get fixed. If you buy the part at German Star in Arizona, and have Mecedes install it, you'll save around $500.

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