just ran to the bank to cash a check, truck has been running smooth as a kitten for 2 years. i get back in the truck pull out and get to the light and i feel the truck shaking a little and idling rough. runs very rough up to about 1500 or 1600 rpm and then it stops missing. it seems odd to me that it only does it at lower rpms, there is a noticable spot where it smooths out. no SES light though. anyone had this happen, think its a COP?, or injector? I did service my clean my k&n about 500 miles ago, but if i got to much oil i would have thought that would have shown up much sooner.

 

It can take a while for a MAF to get enough oil on it so that it messes up the mix enough to cause a misfire.

However, it does sound like a plug isn't firing. Whether or not it's a COP or just water causing it, you'll have to figure that out

Get the computer read for misfires and if you have a single cylinder, remove that COP and see if it's wet in the hole. If so, dry it out and put COP back in. If not, switch that COP with one on the other side of the motor. If it's still doing it, get misfires read again and see if it moved with the COP. If so, replace the COP with a new one.

Otherwise, get a new COP and put it in #1 cylinder. If it doesn't cure it, put the original COP back in #1 and move the new one to #2. Continue this until you find the dead cylinder.

 

well i hated to drive it but i had to take it across town last night and ended up having to drive the majority of a 70 mile round trip with the OD off to keep it wound up enough not to miss, or at least wound up enough that a miss would not make the truck buck and shake so bad, at 65mph around 1700rpm when it would go into a series of misfires it would cause it to run horribly and buck pretty bad. had to be out of town all day for work, but ill have to dead time this afternoon to do some price shopping. being that the truck as roughly 80k on it, if i can get cops cheap enough ill replace them all and know i wont have to worry about it again, i just did the plug about 7k ago, so i know they are still good

 

after pricing all the local parts houses , prices came in from $88.09 from ford ( list price by the way) down to an average of $45 to $50. but O'reiley auto parts had them for $31 a piece, so after 8 new coil packs the truck is running smooth as ever. i had to have had more than one going out, because i unhookded #5 after putting the new ones in and it was not nearly as rough as before. whole process took about an hour

 

31.00 each? i wonder if o'reiley has a website..... i dont have one around me, and that is the best price i have ever heard of. i do have 1 spare oem that i got on ebay though.

 

DId you use Motorcraft plugs?

 

yup, i use motorcraft plugs and filters on my trucks

 

not sure if o'reilly has a web site, doubt it, its a prety good size parts chain here in the midwest though, home office is down in the ozarks somewhere around springfield, mo