My wifes 09 Civic runs rough on idle and the muffler shakes a lot during rest. Our daughters boyfriend is a Honda mechanic and says its the coils. Thing is the car only has 30,000 miles on it and from what I have read coils going that early is extremely rare. Is this rough idle a common problem? If I was going to replace the coils myself is it an easy DIY job? Dealer we bought from did not run any codes. Thanks from a car novice.

 

It still drives OK, except that it does not idle properly? A bad coil would cause the engine to run on 3 cylinders instead of 4 with a noticeable loss of power. It is very rare for more than one coil to go bad simultaneously.

 

Yes, it drives fine so that is why I think this mechanic is wrong. Rough idle only. She has had a few times when it takes a couple cranks to start. Sometimes feels like it's going to stale at lights. From what I have read this is "normal" on new Civics. If not the coils what else could be causing this? Thanks.