Hi. I have a '94 460SE that uses a rectangular ignition coil, which looks like a transformer. I believe it is manufactured by Siemens. I drove the car to the dealer for an unrelated issue, and now they tell me that my coil needs to be replaced. Is there a way to diagnose a failing coil if the car was able to start and drive with it? I have a bad feeling and suspect that the dealer wants to replace a good part. Any ideas?

JGCBAIZ

Maybe you have already solved your problem but to check the coil you can use the old trick of observing it and the wires in the dark - look for arcovers or sparks on outside. Another old trick is to spray a little water over the coil and wires and look for arcs or change in engine's sound (or miss).

Always trust your gut. If you are uncomfortable, get out of the shop with your car. There are other shops that specalise in electrical issues, visit one.

If the coil is failing to put out enough to fire the spark plugs, then it is time to replace it, not before. Besides, there should be plenty of coils in the slavage yards whose owner demolished the car but not the coil.

Drive it home. Pick up a spare used coil and keep it in the boot.

Klaus
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Always willing to listen, just not able to take direction.

Wow, I never thought someone would check the 440 thread, thanks for replying! I actually made a surprise visit to the dealer and my car started right away with the old coil, which they are now claiming is a loaned unit from one of their cars that they installed there... I am running away as soon as possible... Thanks again.

JGCBAIZ

just wondering, how many dealers keep 440's on site?
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If you're not driving it "like its stolen," are you really driving?