'02 E320 Severe hesitation and rough idle
05-17-2007, 03:25 PM
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2002 E320S4M
'02 E320 Severe hesitation and rough idle
2002 E320 4Matic Sport Wagon with extended MB warranty.
When the engine is cold, and the outside temperature is below approximately 10 degrees Celsius (50 degrees Fahrenheit), the throttle is completely unresponsive when the transmission is in drive: if the vehicle moves at all, it only lurches forward a few feet and then comes to a stop. Typically this will happen several times in a row, sometimes the engine switches itself off; by pumping the throttle, it is sometimes possible get the car to move forward at a very slow speed. When this problem occurs, and you put the transmission into neutral, applying the throttle causes the engine to rev normally, but once back in drive, the response is no better and the engine still will not rev above idle speed. After 10 to 15 seconds, this problem disappears and the throttle response is back to normal.
During conditions mentioned above, the engine also idles in a very rough manner, causing the whole vehicle to shake as if being pushed from the outside. Once the engine warms up, the idling becomes much smoother, but still has occasional rough patterns which are less severe.
After several scans by the local dealer, all of which showed no fault codes, one scan finally showed a misfire on two cylinders. The mechanic’s remedy was to replace the main engine computer (said that had fixed a misfire problem on a different E320). The problem did seem to go away for about two weeks after the new computer was installed (perhaps due to a run of milder weather), but then came back the same as before, once again showing no fault codes when scanned.
He then replaced the throttle sensor for the drive by wire, which made no difference. I’m now being told that there’s no way to determine which of the many other sensors might be contributing to this problem without any fault codes to go by, and that MB will not reimburse them for any new parts without fault codes to show that the old parts had failed.
Any help is greatly appreciated!
When the engine is cold, and the outside temperature is below approximately 10 degrees Celsius (50 degrees Fahrenheit), the throttle is completely unresponsive when the transmission is in drive: if the vehicle moves at all, it only lurches forward a few feet and then comes to a stop. Typically this will happen several times in a row, sometimes the engine switches itself off; by pumping the throttle, it is sometimes possible get the car to move forward at a very slow speed. When this problem occurs, and you put the transmission into neutral, applying the throttle causes the engine to rev normally, but once back in drive, the response is no better and the engine still will not rev above idle speed. After 10 to 15 seconds, this problem disappears and the throttle response is back to normal.
During conditions mentioned above, the engine also idles in a very rough manner, causing the whole vehicle to shake as if being pushed from the outside. Once the engine warms up, the idling becomes much smoother, but still has occasional rough patterns which are less severe.
After several scans by the local dealer, all of which showed no fault codes, one scan finally showed a misfire on two cylinders. The mechanic’s remedy was to replace the main engine computer (said that had fixed a misfire problem on a different E320). The problem did seem to go away for about two weeks after the new computer was installed (perhaps due to a run of milder weather), but then came back the same as before, once again showing no fault codes when scanned.
He then replaced the throttle sensor for the drive by wire, which made no difference. I’m now being told that there’s no way to determine which of the many other sensors might be contributing to this problem without any fault codes to go by, and that MB will not reimburse them for any new parts without fault codes to show that the old parts had failed.
Any help is greatly appreciated!
