I have a 2007 F-150 FX4 5.4L and I'm getting the spark plugs changed out on wednesday because I was getting the 40-50 mph shutter. But recently I've noticed that when trying to downshift out of O/D to accellerate, it sounds like there is a little bit of a grinding noise, could that also be an issue with the spark plugs or the throttle position sensor or is my transmission starting to go out? any thoughts would be appreciated, thanks.

 

plugs or coil pack can make it buck and kick and make people think tranny is going out, but I don't know about a grinding noise......how many miles?

 

81,000. Im just hoping that its the plugs and it will be fixed once they get changed

 

So did the plug change fix your issue?

 

Sounds like a coil issue. I've already had (4) coils go out & now another old one is acting up at 40-45 mph. I too thought it was a transmission problem at first but it wasn't.

 

How did you trouble shoot it to a coil? What was your symptoms? Mine will start to shudder or vibrate for a sec when I give it a little gas or there is a little load put on the motor. It will only do it when in over drive and say 1100 rpm.

 

A misfire can feel like a transmission issue with bucking, stumbling, hesitation, at certain rpms.

 

I've felt a cop going bad. Had one go out on my 01 f150. That felt more like a bucking or a hiccup. The issue with my 08 is more of a loud vibration or deep rattle in OD when its at 1100 rpm 40-45mph and you give it a little gas or start to go up a incline and the truck gets a little load on the motor. It does not do it all the time. The dealer is having a hard time reproducing the issue.

 

My 2004, has a slight shudder at around 45mph. Like it doesn't want to shift down into third from OD. I've had the shudder since I have owned the truck, even after servicing the engine, tranny, fuel filter ect and of course on engine codes. I assumed after about 90000 miles its just one of those things. It doesn't happen every time, only if I am already in OD, and going around 45 right before the transmission wants to shift down into 3rd with a little bit of a load. Normally i just press the gas slightly and she will go on into third, or turn OD off.
Anyways, lets us know what you find out, and if it stops.
Ricky Finch

 

Spark plug change and transmission serviced has seemed to fixed my problem. I also mixed in some shutter stop in when I did the transmission