Misfire issues
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Newbie
Joined: Jan 2010
Posts: 3
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06 C230
Misfire issues
Ok, I posted this in the W203, but figure I'll try here too. I have an 06 C230 with the 2.5 V6 and it has 128k miles on it now. About 10k miles ago, it developed a bad miss and started flashing the check engine light. I pulled the codes and it showed exhaust cam, bank 1 over retarded and 2 cylinders with misfires. Since it had so many miles I figured it needed plugs. I have also found out from reading how to fix the cam timing problem, but it has not been done. I bought plugs, but when I removed the old ones, the ground strap was bent over touching the electrode on the cylinders showing the misfire. We put a scope in the cylinder and couldn't see any mechanical reason for them to be bent. I went ahead and changed plugs and it ran great for a little while. It started missing again, so I pulled the plugs back out and sure enough, even the new ones have the ground strap bent. Codes were the same, just misfires. I bought a set of coils thinking maybe the coils themselves were bad. Ran great for a while again, but now it's missing. The codes have changed though. Instead of a certain cylinder misfire, I get a random misfire code and a coil circuit code for all 6 coils. I am my wits end with this thing!
Thread Starter
Newbie
Joined: Jan 2010
Posts: 3
Likes: 0
06 C230
Still fighting this damn car! Checked the fuel pressure today, 58 at idle, dropped to about 55 under a load, so I don't see that as a problem. Checked the codes again, still getting circuit faults for all 6 coils, but had specific misfire codes for 2 cylinders. Also had a too lean at idle code for bank 2. A buddy in Dallas thinks its the intake runner flaps coming apart, but it seems to me that it would be more consistent if it was a mechanical problem. Only good news was that my exhaust cam on bank one didn't show a code for over-retarded. Any help or thoughts would be much appreciated!
