Ignition Coils Failed - 97 540i

[///Matt]

On my 97 6 of the 8 coils are thought to be failing (misfires, throws out codes etc, extremely rough in cold) How/why is this happening? Is this a common problem???

Regards,

[Dirty_Tool]

Hey Matt,
i know youve posted a few times on the misfiring issues on your car. So is this the ultimate cause? The coils? Are you certain? If so then its not unheard of to have several go bad. I wouldnt say its real common on your year and model though. The newer Bremi coils on the later model cars are failing left and right and coil failures are not unheard of across all models but on your car id say 6 bad coils isnt common. This is why I ask are you certain that they truely failed? More common what causes misfire faults on your model is Failed Cats and Intake leaks/PCV plate failure. Hey anything is possible though of course, let us know if this is the final verdict or if the problem comes back.

DT

[billB]

While odd in terms of numbers- 6 out of 8- but it all depends on how many miles/how old these coils are. When did you change them last? through out check engine codes? what are they?