[Giri]

As I mentioned in the title my car has a pretty rough idle. If I have bottle of water in my cup holder i can see a visible shake. Anything in the passenger seat would also vibrate enough to make a noise.

Come to think of it, I also see and hear the vibration in things that I leave in my passenger seat while driving.

I just replaced both spark plugs and that didn't help the idle (although it did help with my gas mileage)

I have a set of 4 of OEM coils that I bought and was considering returning. Should I replace them? The car is at 70k miles.

[wookwook]

did you say it was in gear or neutral? M6 or A8, just at idle? its stretch but..... something off balance on the pully's. or the flywheel or torqconvert. you could try swapping a couple of existing coils to see if theres any perceptible change. You could try just one new coil one plug at a time..



try a auto parts place that will let you get a scan. or, hit up a garage. the peace of mind may be well worth it at this point. could be a clogged or bad injector? get the misfire metrics. anything sound different? carbon on the valves? hows the power been. a good garage would spot it quickly.

[Giri]

Originally Posted by wookwook

did you say it was in gear or neutral? M6 or A8, just at idle? its stretch but..... something off balance on the pully's. or the flywheel or torqconvert. you could try swapping a couple of existing coils to see if theres any perceptible change. You could try just one new coil one plug at a time..



try a auto parts place that will let you get a scan. or, hit up a garage. the peace of mind may be well worth it at this point. could be a clogged or bad injector? get the misfire metrics. anything sound different? carbon on the valves? hows the power been. a good garage would spot it quickly.

I notice it mostly when I'm parked flying my drone, with the engine on and the car is in Park.

[cKurmaro]

Originally Posted by Giri

As I mentioned in the title my car has a pretty rough idle. If I have bottle of water in my cup holder i can see a visible shake. Anything in the passenger seat would also vibrate enough to make a noise.

Come to think of it, I also see and hear the vibration in things that I leave in my passenger seat while driving.

I just replaced both spark plugs and that didn't help the idle (although it did help with my gas mileage)

I have a set of 4 of OEM coils that I bought and was considering returning. Should I replace them? The car is at 70k miles.

What did you gap the new spark plugs to?

[Giri]

Originally Posted by cKurmaro

What did you gap the new spark plugs to?

I got a set of the OEM plugs which I think are pre-gapped to 0.035 - Interestingly my gas mileage went up significantly with the new plugs.