Originally Posted by waldig
My 05 has 22,245 and is driven, lightly. Gas does not cause carbon , lack of the PROPER amount of air does. High test has knock modifiers that REGULAR does not have, same same overall. Gas stations try to add all sort of stuff, newest is nitrogen, before that they were addding oxygen.....ho hum.
.
I surmise that the plug pair were not firing and loading up the plugs. As I said start the car with two plugs on the valve cover and see how they seem to fire( yes you have plugs in the cyclinder while you do this and yes they are not "connected" during this test. Atmospheric pressure is no test but will say if there are firing signals are sent to the coil pac.
.
If the plugs fireon the valve cover, remove the coil pac and swap to the other side of the engine and see how the plugs READ after 500 miles to see if the pack or cyclinder have the problem. Cheers, Woody
.
BTW did a/c work for the inventor of the coil pack design - electromotive - what a dickk, glad he's gone. If the plugs dont fire normally oil will build in the cyclinder and coat the interior/plugs.