I have 60,000 and it is still under warranty, so I called the dealershaft and they want almost $200 to check it out. They did say that when we get a lot of rain, they see coils go out, as moisture gets down in the plug boots. But, they aren't covered by the warranty. I would say that is a poor design. So I took it to an independent shop, and he said the codes were reading a problem in #4 & #7 cyls. but not bad coil codes. When they pulled those 2 plugs, they said there was a little moisture, and they blew them out. The plugs showed wear, but not worn out. So I changed the plugs, and cleared the codes, and it ran good when we test drove it. A little while after that I went to the store and it started to miss, but not as bad, and the CIL hasn't come back on. I was going to change the fuel filter, but I guess you need a special tool. Can anyone point me in the right direction on this?

 

Swap coils 4 and 7 with coils from good cylinders to see if your misfire codes change locations. Parts stores can pull codes for you no charge. Although if your truck is still under warranty (an extended warranty, I'd guess?) why in the world does the dealer want $200 to check it?

 

I don't know, a local shop did the above work for $84. Thats why I didn't wan't to take it to a dealer. I actually switched the #4 and #1 coils for that reason, plus now if it shows bad, it will be a lot easier to replace it. Thanks for the response.

 

There's a couple of problems with what they told you. Your mechanic cannot tell if the misfire is caused by the coil, plug, wire, or anything else. The only codes that can show up are P30x, for whichever cylinder it is. I know this is a pain noe, but pull every plug wire and stuff it with di-electric grease. This'll keep moisture out in the future. While you have the wires off, but the plugs still in, use an air compressor and blow all the crud out of every hole. Chances are it is not your fuel filter. Not a bad idea to change it, but it's not your problem.

 

Hopefully, you used either Motorcraft or Autolite plugs. They're the best plugs for these engines at that price range.

I'd suspect your plug wires are now the problem (unless you used crap plugs). I'd recomment replacing them with a high quality wireset and stuff both ends with dielectric grease as suggested.

Steve