Just will not run, engine shuts off or runs rough?

JACK ROHDE

MEMBER
2007 FORD F-150
5.4L
V8
4WD
AUTOMATIC
167,000 MILES

It will start and run fine until the engine warms up and then it either dies or runs so rough you cant go anyplace. Backfires and runs real rough. I turn off the engine and coast for a while in neutral. Then start it up and it may run okay for a few blocks and it may not. I have replaced the gas valve up on top and both catalytic converter sensors and both camshaft sensors. I am stumped.

Sunday, September 28th, 2025 AT 9:50 PM

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
54,591 POSTS

It sounds like you have a crankshaft position sensor that is not working correctly, also do you have a check engine light on, if so we should run the codes to see which ones are stored, this guide will help you:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

I have also seen the engine coolant sensor start to short out when hot and cause strange engine problems. You should be able to se the engine temperature on the scanner and if it goes to a strange value you know it is the sensor. Here is the location of the crankshaft sensor which does not always leave a code. Check out the images (below). Please upload pictures or videos in your response of any problems so we can see what to help you with.

Image (Click to make bigger)