A brief grinding sound immediately after starting the engine -initially in cold engine (winter) but gradually more frequent and then always. I went to dealership, they suggested the replacement of unit (1000 USD). Sound was not only irritating but also embarrassing.

Believe that this should have been a recall...never had this issue in all of my 20+ cars.

Ignition Coil (Bank 1,2,3,6)

Update from Sep 29, 2015: Believe that this should have been a recall...never had this issue in all of my 20+ cars.

Ignition Coil (Bank 5)

Update from Sep 29, 2015: Believe that this should have been a recall...never had this issue in all of my 20+ cars.

Ignition Coil (Bank 1,2,3,6)

Believe that this should have been a recall...never had this issue in all of my 20+ cars.

Update from Sep 29, 2015: Believe that this should have been a recall...never had this issue in all of my 20+ cars.

ignition coil (Bank 4)

Update from Sep 29, 2015: Believe that this should have been a recall...never had this issue in all of my 20+ cars.

Ignition Coil (Bank 5)