Hello all new here to Volvoforums. I am trying to help my father out. His '97 960 has a rough idle. Im thinking it may be a coil pack, what is the proper way to test the coil pack? I also noticed that the 3rd spark plug from the front was soaked in oil seems to be a worn piston ring. I guess that may cause the rough idle also. The car has 108k miles but doesn't make sense for it to be smoking a puff of white smoke upon startup at this mileage. I think the miles may be rolled back the brake pedal looks seriously worn!

 

Rough idle, missfire? Check Engine light on? This is OBDII car--a simple engine analyzer will tell you if a coil pack is dead. If you disconnect the packs, one by one, if there's no change, that's the one. Oily plug, depends... Take a compression test to be sure, always a good way to start a diagnosis. Worn piston ring? Unlikely, Volvo rings go forever. 108k, the pedal may be worn, normal, they wear fast. Wild guess, I'd say a burnt valve... A compression test will tell...