Hey guys, I have a 03 expo with a 5.4l engine, last night I started getting the misfire issue on cylinder 6, now my problem is that I just replace the serpentine belt last week and Im just a regular guy trying to save a buck on repair and do them myself. I dont have much experience but trying my best.

Now im thinking but can the misfire be due to replacing the belt? was I suppose to put it on a particular position like timing belts? not to sure. Any suggestion would be highly appreciated. Of course I was planning on taking the trip down to Disney in 2 month with all the kids but now Im a bit worried if the truck will have any issues.

 

The serpentine drive belt is not clocked in anyway so that is not the issue. It sounds like you have a misfire due to a bad COP, cracked insulator or bad plug. My bet would be a cracked insulator. How many miles on the truck and when was the last plug change?

 

Thanks, I taught I replace the belt some how wrong
The truck has about 116k on it, I had the truck since about 100k and I have'nt change the plugs.

 

The plugs get changed at 100K and it can cost anywhere from $400 on up to change them. The cost goes higher (and often does) if other problems arise during the replacement. It sounds like the previous owner traded it in just as all of the maintenance issues were coming up. I suspect you will have to change the spark plugs. While you're at it, have the lower ball joints inspected, they're likely due as well.

 

Thanks, is there any easy way to check if the plugs are in fact bad, just dont want to cough up 400+ for plugs and than come to find out it was bad coils or cranked insulator.

 

You could pull out an inspect one or two of the easy to get to ones.

 

I had a misfire too back some time and it was a bad plug, just changed all of them per the 100,000 mile Alloro spoke of. Also check to see if the boot to that sparkplug didn't pop out somehow, mine did and I just pushed it back down, alls good.