merc C class 220d - EPC problem!

[georgehoffman]

Hi, i have a problem with my manual diesel merc. Runs fine most of the time but all of a sudden the EPC light comes on and the car will only rev to 2000 rpm and surges, it will only run in 1st,2nd & 3rd when this occurs.If the ignition is momentarily switched off it can cure the fault for a few seconds or a few miles. This problem can happen straight from cold or it can go for miles before it occurs. Mercedes say they can put it on their machine and it will give fault readings but then it is a matter of changing various things to see if that solves the problem but this is an expensive process to me. I feel it cannot be the fuel pump but possibly a sensor or relay problem. Any suggestions please. thanks.

 

[jberks]

There is no getting away from the fault codes. Otherwise, you're swapping parts on the off-chance and that can be very expensive. The computer has detected the fault, shut everything down and logged what it detected so you need to know what it thinks is wrong. DO NOT GO TO A DEALER!!!! Find yourself a local specialist and get them to do the diagnosis. Chances are that whatever it is, the part will be the expensive bit and the fitting will be minimal so you aren't going to save much DIY but the specialist will advise the cheapest course.
If you post where you are, someone will recommend someone you can trust.

 

[georgehoffman]

cheers, have been to our local guy a few times but each time the damn thing behaves itself, next time it plays up i'll take it straight to him & hope he's not too busy.

 

[jberks]

Even if it behaves itself, it will still have logged the fault. So if your guy has the right kit, he will be able to pull the codes.
Not sure if you are using one already, but there really is no substitute for a proper MB specialist. A jobbing mechanic, no matter how good, will struggle with ECU issues on Mercs. They are fine for brakes, service etc but this needs an expert with proper MB diagnostic computers.