gocusetupper

When the overdrive is on in my '04 F150, the transmission slips. When I turn it off it's ok. 2 questions. 1-Is it OK to keep driving like this and 2- WHat might the cause be. Thanks in advance!

originals

I thought the same thing in my 07 with a 5.4, only does it in mine from speeds between 40 and 55. I changed the trans filter and fluid but still does it, I've read some other threads on here that are saying the spark plugs have fouled out. I have yet to do the plugs on mine, waiting until the spring so I can't confirm if that's it 100%. Maybe we can get some others to chime in on this one.

corey_lax

Almost 100% of the time, people think it is a transmission issue when it is actually a misfire. When did you last change the plugs?

jamie930

slips or jerks and bucks?

the jerking and bucking at low speeds in OD is a misfire

homer

If it's slipping then it's probably more likely in the transmission but if it's jerking like the others say, I'd check your plugs and/or coils. Also, unless there are enough simultaneous misfires, it will not set a code on the dash. The computer wants to see enough misfires in order to consider it an issue.


I just went through it myself with the bucking. I had a #6 coil failed, changed it, fine since. It didn't slip though, it bucked/jerked. I couldn't find which cylinder was misfire until I finally went to pass someone on a BC highway and that cylinder basically kicked out during the pass. At that point, it finally set a code for me so I had something to work from.

gocusetupper

Thanks for the info.! Never changed the plugs. I'll look into the coil too. Garage should be able to diagnose, yes, maybe?

bRoc4

I'm having the same problem with my '04 F150 5.4L. I thought it was a misfire so I took my truck into my local ford dealer to get the plugs changed. They called me back before they did the plug change and told me that I have an sludge problem and that my motor was shot. They refused to change the plugs and instead gave me a quote for a remaned engine. The quote was over $7K. No didn't not take their advance so I still have the same motor in my truck. That was more 5K miles ago. My truck is still running but driving it on the highway I still have to turn the O/D off and even then I will still get the bucking/jerking on occasion. I'm really not sure what I should do with it. I think my next step is to try some engine Kleen to try and get out the sludge and maybe change the PCV valve. Then take to a different shop for new plugs. Anyone have any more suggestions?

Eric0508

More than likely there is no sludge. Just take it somewhere else to do the plugs or better yet do it yourself. I can almost garuntee you that your bucking/jerking is plug related. They probably took your oil cap off, saw some yellowish goop on there and concluded your engine was shot. Screw them, get your plugs changes and enjoy your truck for another 100K. Gahh! dealers annoy me.

epedwards

I have a 2004 f150 and had the same problem. Only in OD when I went to give it gas it would start bumping and feel like I was driving over the rumble strips on the side of the highway. Changed my plugs and coil packs and still doing it. Took it to my mechanic and he serviced the transmission and added shutter guard. That fixed the problem drives fine now.

Dsherman

I had this happen on my '05 Screw and once I changed the plugs this went away! BTW I broke 6 out of 8 replacing them. Get the Lisle tool you'll need it on a '05.