Engine began running rough shortly after oil change and tire rotation. During acceleration, sounds (feels) like at least one cylinder is missing. I suspect the coils, but can not get the check engine to come on for diagnostics. I checked as many connections as I could hoping that the service tech may have puller out a wire or vacuum hose. Also ran fuel injector cleaner just for the heck of it. Plugs are not old enough. Thought I'd ask before I limp it down to a service center and get raked.

I should have kept up with the newer engines - there are few MECHANICS left in the world.

 

Remove the COP's (Coil on plugs) near the oil filler tube and see if OIL got spilled into the spark plug holes.

If water and oil gets into the spark plug holes, then the oil will sit on top of the water and keep the water from evaporating out of the spark plug hole.

 

I have a '01 with a 5.4 (supercharged), and mine has started the same thing over the past couple of days, but getting worse. It started when I had about a 1/4 tank of gas left, and it's just gotten worse after a fillup. I swapped out the fuel filter tonight, but it's still there.

And I haven't done service lately at all... it just started hesitating, and missing under acceleration. We've had a ton of rain lately, so I'm wondering if there's some condensation buildup, and that's causing the problem. I just put a bottle of Techron fuel system cleaner in, hoping that fixes it.

Any other thoughts?

 

Just had my 01 serviced and thought my #3 and #7 coil packs went bad, yet the plugs were FUBAR. Turns out when I had the truck serviced in Feb and had the plugs replaced the tech didn't gap them right -- yet rain can cause the the coil packs to fry if water gets into the boot

 

I've had several coils go bad, and one plug get totally f'd. None of this set of the CEL until it got real bad. Just tough it out till the CEL comes on to determine which one it is, or get a new one and start going through each cylinder (waste of time to me). I guess you could also check the primary voltage on each one as well, but this can be a tough way to do it also.

Maybe there is also a way to hook the code scanner up while you driving. It might detect it when its happening.