I did a search and couldn't seem to find the exact same problem listed elsewhere. My lady friend has a 2003 E320 w/60,000 mi. When her car gets warmed up and she is driving slowly (like in a parking lot) the car has what feels like a surge in the throttle. It isn't harsh at all, just very obvious. She took it into the dealership. They diagnosed a "throttle pedal". I wasn't there so I figured they may have said throttle position sensor. Well, $500 later, the problem hasn't changed at all. Any ideas? Thanks.

 

I had that symptom when my torque converter was damaged because of glycol contamination.

 

Ouch. That sounds expensive. How did glycol get in the torque converter. Was the glycol also in the transmission?

 

03s and some 04s have a sometimes defective Valeo radiator which allows coolant into the transmission. Your lady friend may have another issue causing the surging. I haven't experienced the surging since I had my trans and torque converter replaced. I did have other symptoms besides low speed surging, but I think it was the first symptom. There are extensive threads in this forum about this problem. Search for "valeo radiator" and "glycol contamination" to pull up the threads.

 

Thanks. I'll search those phrases.

 

Have ATF analyzed http://www.blackstone-labs.com/ for contamination and since repair attempt failed request dealer check for /apply ECM update(s) at no cost