Rough Idle and Hesistant Start
I currently own 1998 E-320. I have observed couple times during the cold weather that the engine idles roughly (after 2 minute warm-ups). When it is about to be driven (transmission to D position) and the gas pedal is pushed, there is a split-second pause and the car is hesistant to move forward and the engine revs up. And suddenly it picks up the speed and lurks forward. This is a safety concern for me. However, when the engine is warmed up enough, the problem does not repeat itself. And I observed this only with a cold weather.
This is how I have observed it in my routine drive:
1. From the cold start in a cold weather, I let the engine warmed up for 2 minutes.
2. I start to drive the car and stop at a red light. Usually after several seconds sitting idle, the engine drops a 100 rpm and starts to idle roughly. I can feel the whole car shakes.
3. When the traffic light turns green, I push the gas pedal and the engine revs up and won't move for a split second and suddenly the engive revs higher and the car literally jumps forward very fast.
I brought the car to a MB dealer several weeks ago and they replaced a crankshaft angle sensor (?). But this still doesn't resolve the problem.
Does anyone have this experience before or know the source of the problem? The dealer wants to run another diagnosis and a couple hundred bucks from me. I think it is ridiculuous. They probably want to rip me off.
Please your advice. I will really appreciate it very much. Thank you.