i'll try to explain what the truck is doing best i can. i'm not sure if it's the engine or tranny. when you lug the truck on a hill or put a load behind it and lug it the truck jerks like the engine is cutting out or the tranny is jerking,i can't tell which. you can drive it all day long on a flat road or small hills and you can't make it do it. it does it worse going up a hill with a load behind it. you can lug the truck on a steep hill let off the acclerator and mash it back down and it will do it almost every time. i've tried overriding the overdrive and it still does it. if you keep the rpms above 2000 up a hill it won't do it. i've had it checked by a transmission shop and they couldnt make the truck do it. also it doesn't throw any codes or put the check engine light on when this happens. 2007 F150 supercrew 5.4 auto, with 88,000 miles.

 

You have a mis-fire.

 

thks for the reply!! i'm wondering why it doesn't throw a code if the engine is mis-firing.

 

It can take quite a while for the the computer to catch the misfire, even with all that bucking. With 88K miles I would think it might be time for a set of plugs. They have a 100K service life but, I changed mine at 67K and they were shot. If the plugs have been replaced make sure they are motorcraft and start thinking about COPs.

 

I've had to drive around with the scanner connected to catch the culprit.

 

thks. for all the info!! i've read some nightmare tales about changing these plugs. is this something i can do or do i need to take it to a ford dealership. is my 07 one of the motors that are bad to break the plugs getting them out? any tips on getting them out!

 

i bets its plugs and COPs

 

I had to replace all my plugs at 89K and one COP and then 5k later another COP. I would not replace the COP's until they start to fail it is usually not worth it because it could be a long time between failures.

 

did "you" change the plugs or have a shop do it. just called the ford dealer and they want $350 to change the plugs! i've heard some horror stories about the plugs breaking off or pulling the threads out of the head.

 

thks for all the info!!! found a local shop that has a good reputation and has done several of these plug changes,they will do it for $130 plus parts so i'm taking it in friday to them.

 

Good luck to you. I just changed the plugs in my 07 Screw 4X4, 5.4 last weekend and 5 of the 8 plugs broke off. Fortunately my son in law has the extractor.

 

I got them changed,three out of 8 broke off. Total cost counting the $12 each plugs was $320

 

so did the plug change fix your cutting out? mine didnt. Still does it just maintaing speed on the highway. Frusterating. No codes either.....