Back in January, cylinder #6 in my 1998 M3 stopped functioning and the Check Engine light came on. Further inspection revealed a melted coil. I replaced the coil and the problem persisted, melting another coil. Unable to figure out what was wrong, I took the car to my local BMW shop (not a dealer) and here's what they did:
Replaced coil and injector. Did not cure the problem.
Checked the wiring harness. Found nothing wrong.
Replaced the ECM and this cured the problem for about 5 days, at which time, the problem returned.
Does anyone out there have any idea what could be wrong? I've spent $500 in diagnostics with this guy, who is not fixing the problem. (The rest was covered my warranty) I want to be sure he is not just stringing me along.
Thanks to anyone who can shed some light on this.