I have a 2004 Ford escape 3.0 and recently
replaced all gaskets, valve covers and intake
manifold, plus all spark plugs. The vehicle ran fine
prior to that but after all of the above it ran rough. I
checked the spark plugs and found cilinder number
4 was not firing. I did not check numbers 1,2, and 3
as I would have to remove the intake again. I also
noticed that the elbow attached to the intake was
collapsed and cracked so I replaced that and not
sure how it ran fine prior to that. It was dusk by the
time I finished and noticed the catilitic converter
was glowing red hot. Is this because of the unburnt
fuel and what could be the causes?
yes, due to unburnt fuel. You'll need to scan for the codes to determine which cylinder is misfiring. You need to recheck your work, especially since you didn't have an issue before and check all connections and vacuum lines. Sometimes people mix up the cylinder #5 plug with the #6 one if you removed all the coils at the same time. I always remove one at a time when I replace plugs on the 3.0L's.
I have checked 3 times over and didn't want to remove the intake again. The coil harness is arranged in a manner that the coils can not be mixed up due to the length of the wiring. I do not have a computer code reader but have been told that it is not uncommon for the coils to go bad after this procedure being that the vehicle having 144,000 and never having been replaced, including spark plugs.
Search Maintenance & Repair Questions
Maintenance & Repair Experts