Thought I would keep this one separate from my P0412 CEL post from yesterday as I am now not so sure they are related as the code came up 2 weeks after the symptoms appeared.
'96 Mercury Sable with 3.0L Duratec engine.
3 weeks ago a mechanic replaced all the spark plugs and wires, apparently he had to take off the upper intake manifold to replace the rear bank plugs. Car was running perfect prior to the plug change.
100-200 kms later, the engine idles smooth with an occasional stutter, but misses and bogs down when accelerating. It seems to smooth out in the higher revs with an occasional miss. Seems to be worse when fully warmed up. The Serice Engine Soon light came on this week and my friend pulled out a P0412 error code. No other codes in memory. Code was erased and the light came back on after just 5 minutes, same error code.
Mechanic says it ran fine when he gave it back to me, refuses to bother checking into it. Couple other mechanics looked at it but one doesn't know what the problem is, the other says maybe coil pack but he doesn't know for sure.
One other thing, when I was pulling the plug wires while the engine was running to see if perhaps I have a bad plug or wires by watching for any differences in the engine running, I noticed when I pulled the wire boot out fully on the 3 front cylinders, the boot insulator end was arcing across to the metal at the top of the valve cover when held approximately 3/8-1/2 inch away. I doubt that is normal right? Could it be the stumbling is caused by the plug boots being bad and arcing acorss to the valve cover rather than thru the spark plug?
Last time I did mechanical work was way back on the old muscle cars. When we checked for a spark, we would insert a small screw driver into the boot and bring it close to the valve covers to check for a spark arcing from the screwdriver to the cover or bolt. The boot insulators themselves would not create a spark. Could I have been given defective wires?
'96 Mercury Sable with 3.0L Duratec engine.
3 weeks ago a mechanic replaced all the spark plugs and wires, apparently he had to take off the upper intake manifold to replace the rear bank plugs. Car was running perfect prior to the plug change.
100-200 kms later, the engine idles smooth with an occasional stutter, but misses and bogs down when accelerating. It seems to smooth out in the higher revs with an occasional miss. Seems to be worse when fully warmed up. The Serice Engine Soon light came on this week and my friend pulled out a P0412 error code. No other codes in memory. Code was erased and the light came back on after just 5 minutes, same error code.
Mechanic says it ran fine when he gave it back to me, refuses to bother checking into it. Couple other mechanics looked at it but one doesn't know what the problem is, the other says maybe coil pack but he doesn't know for sure.
One other thing, when I was pulling the plug wires while the engine was running to see if perhaps I have a bad plug or wires by watching for any differences in the engine running, I noticed when I pulled the wire boot out fully on the 3 front cylinders, the boot insulator end was arcing across to the metal at the top of the valve cover when held approximately 3/8-1/2 inch away. I doubt that is normal right? Could it be the stumbling is caused by the plug boots being bad and arcing acorss to the valve cover rather than thru the spark plug?
Last time I did mechanical work was way back on the old muscle cars. When we checked for a spark, we would insert a small screw driver into the boot and bring it close to the valve covers to check for a spark arcing from the screwdriver to the cover or bolt. The boot insulators themselves would not create a spark. Could I have been given defective wires?
