Skorp

So I really am at the end with my 2005 CLK 500. I've taken to shops before and no one can find the problem as all systems show working with no fault codes so I am left with getting used to it. Basically, idle is rough sometimes and does some shaking from time to time, but not always. Around 5% - 10% of the time and only when coming to a complete stop after driving. Today though, I drove and around 6 minutes in I went to stop at a red light and then bam my car lost power, but the dash had lights on at the same time except for the check engine light. I could not accelerate though or anything. I had to quickly turn the car off remove the key and put it back in and turn it on and it worked and was able to drive normal. Spark plugs are new a few years ago and the CPS sensor was replaced 2 years ago. Not sure what else to do at this point if a shop can't find out, how could I find out myself. What else could it be or should I look into? Really want to drive this car again, but it is just stressful. Used to be such a fun and smooth ride.

TL;dr: Rough idle sometimes coming to a complete stop with shaking (About 5 - 10% of the time). Lost engine power, but dash lights were on and had to turn car off and back on at a red light. No warning lights and no fault codes. Shops can't find the problem. Sparks plugs and CPS sensor were replaced before.
Thank you!

GNShayne

I had same thing happen, on my 05 CLK 320. I used Lucas additive to clear fuel injectorsf and fuel system, and no problems since.

Trotter

I had an idle problem with my 04 CLK 500. The fix was simple. When I had removed the air filter box from the engine and replaced it, I didn't properly seat it onto the mass air sensor. After proper seal the rough idle was gone. I would check it out just to make sure..