BenzWorld Junior Member
Date registered: Jan 2011
Vehicle: 2004 CLK 320
Location: Sherman Oaks, CA
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New here...Misfire problem !
This forum is pretty cool. Hope to meet other enthusiasts on here. I am based in LA and just got a used 2004 CLK. It has 73k miles on it.
I found this forum searching for engine misfires. One day, a week or so after I had bought it (and letting it sit most of the time really as I had my old car I just sold), I started up the car and felt a rough idle and the CEL went on. I pulled the codes and my family mechanic says its a cylinder 5 misfire. Pretty bummed out but my mechanic tried swapping coils, spark plugs, and wires. All are ok and its still idling rough with no CEL now. The family mechanic said it is probably the fuel or some kind of carbon build up. He gave me some fuel cleaner and said to drive a couple tanks and get some more cleaner. I drove it around a bit, and I notice that:
1) idles rough. RPMs go to 1100-1200 on initial start-up, then drop to around 650-700. The car idles rough when its idling 650-700 RPM.
2) I don't feel the car shake or move at all while I'm driving. Only at a stop light and when I start the car.
3) It looks like a lotta smoke comes out of the exhaust. But it has been cold and I understand this isn't the same kind of car I used to drive (a Japanese car)
I went ahead and got a second opinion. It's at another mechanic right now in Van Nuys that I found through here (Boulevard Auto) and so far they did a compression test and everything looks fine. The mechanic (Nelson) told me today that they swapped the coils to see if the rough idle moves. No word yet. They also looked at the spark plugs, inspected the wires. Nelson also found the cylinder 5 to misfire...
Hmm what else can it be? All the misfire threads here are inconclusive...I hope I can solve this quick and that it doesn't cost me too much money. Any suggestions would be really appreciated.
Thanks in advance!