Edmunds Answers

Answers

  • zaken1 06/03/12 3:26 pm PST

    Did you clear the trouble code with a code scanner after replacing the parts? Those codes do not go away by themselves; often not even if the problem is fixed.

    If the cylinder is actually still misfiring; it could be caused by a sticking EGR valve, or a vacuum leak in the intake manifold (such as the brake booster hose or the hose to the transmission modulator having come loose) or by a low compression cylinder.

    It is also possible that the wires were installed in the wrong order. This motor's firing order is 1-8-4-3-6-5-7-2. Cylinders 5 and 7 (the 2 cylinders closest to the firewall on the driver's side bank) fire consecutively; and they are next to each other in the cap. It is very easy to switch those 2 wires.

    You also might have a sticky valve in that cylinder. Buy a large size bottle of Chevron Techron fuel system and combustion chamber cleaner, and add the whole contents to the gas tank just before filling it up. It usually takes 50-75 miles of driving for this unique formula to clean out engine deposits.

ADVERTISEMENT

Top Engine Misfire Experts View More

Rank Leader Points
1. zaken1 1105
2. MrShift@Edmunds 720
3. karjunkie 425
4. Stever@Edmunds 125
5. thecardoc3 90
6. 0patience 75
7. snowball2 75
ADVERTISEMENT