January 3, 2004Well, I have had my 1997 F150 5.4l for almost 1.5 years and have my first problem. While towing my boat from the dealers, my truck started riding very rough and the check engine light came on. Dropped the boat off and headed to Autozone to have the code checked. Figured it was a misfire somewhere, and was right. Misfire in Cyl 4. I will replace the coil and hopefully that will do it. I am also going to replace all of the plugs, even though it is not quite 40k miles, they are the originals. Also going to do the PCV valve and fuel filter while I am at it. Hopefully it will be all done tomorrow.
Forums : Engines-Gasoline 8-cyl : First Problem with my truck (9 Views)
January 3, 2004While you are at it, you should replace the plug wires. Can't hurt!
January 4, 2004Just finished replacing the coil and plug in #4 cylinder and she now runs like a scalded dog
What a pain in the butt though. #4 is the passenger side rear. I replaced the plug at the same time as the coil because I really don't care which was bad, I just did not want to screw around with it too long.
Question though. I think the old plug was gapped a little small and the coil I replaced was aftermarket, so it was replaced before. If the gap is too small, can it cause the coils to fail? The book says to gap at .054 and the old one was about .050-.051 Would that make a difference?
Anyway, now going to replace PCV and Fuel filter...Oh joy. I will do the other plugs later, I am a little burnt out right now and my back is killing me.
I don't think the wires are likely to go bad as they don't carry much current, like other motor's wires.
January 4, 2004Dont quote me but i belive there was a problem with something leaking onto the coil that would cause a failure.
January 4, 2004If you are having problems with cylinder 4 check out the A/C line that is above it. Most problems are from condensate dripping down on that particular cylinder.
January 4, 2004i agree with the leak onto the coil.. my bros had a misfire and they said they had to check cuz the bigger motors had that problem.. my moms expy has the 5.4 and is goin in on tuesday to check it out.. hope its easy and doesnt cost a lot.. good luck with urs too
January 4, 2004Yes, there is a TSB on that leak, I believe, and you cannot really change the plug wires since you don't technically have any, as you already know. The fuel filter is super fun, I will be think of you.
January 4, 2004The coil TSB was for the expeditions... there was a hose for the rear heater core that went into the firewall right there that would leak and drip on the coil. That would eventually cause the problems you described.
As for the fuel filter, it takes all of 2 minutes to change it... IF and ONLY IF you have the right tool for the job. Spend the extra $5 on the generic plastic fuel and AC fitting disconnect tools... they make the job infinitely easier! Pop the safety catches, slip the tool down the filter nipple into the connector, and the fitting will literally slip apart with no trouble. (just make sure the fuel pump fuse is pulled and the key is off to be safe)
January 4, 2004Well, I realized I needed the tool when I went to do it. I did not feel like going to the Auto Parts store, so I fashioned one out of sheetmetal and it worked out great.
I did not see any evidence of a leak above the coil, but there are several pipes running right above it. What can be done if condensation is leaking down into the coil?