Hi, I found this site while looking for information on my truck.

I have a slight problem, after an extensive search for the coolant temperature sensor on my 4.2 L Ford F150 I think I finally located it with some info I found on this site. It was hidden on the drivers side of the engine block, near the firewall. While trying to remove the sensor, it snapped at the base, leaving the majority of the sensor in the hole. No leaks that I can feel, however I can't get the remainder of the sensor out of the hole. I was wondering if it would be possible to relocate the sensor to the plugged hole near the thermostat, splicing in some wire and reusing the current connector. Would this cause any problems with the way the engine runs? The reason I was looking for the sensor is because the engine has been reading cold on the guage all winter, even with the engine warmed up and throwing lots of heat into the cab. At the same time this occurred the engine starting running at a fast idle all the time. When the engine is warm I can drive at 60 KPH or roughly 40 MPH without touching the gas pedal!!! Any quick assistance with this would be greatly appreciated!! Thank you!

 

Howdy! and welcome to FTE and the 4.2 forum.
Glad to have you here.

I do believe the early 4.2 engines had 2 different temp sensors. But, soon enough, Ford went to using only one sensor.
There might be a reason you couldn't use the "spare" hole, but I don't know what that reason would be.
The one possible thing that comes to mind would be a possible effect on the ECU (computer).
The ECU uses many variables to control timing, fuel delivery, etc. So changing the loaction of the temp pickup might have some impact, but it might not.
If it we mine, I'd try it and see. I might be wrong, but I'd expect it to work OK.

Let us know how it turns out.
First time anybody has ever asked that and I'd like to know the outcome.

Again - welcome to FTE. Hope you stick around.

 

It turned out I had to jury rig a connector, because the connector was a little different and wouldn't line up right!! However I got it all back together and it appears to be running better than before!! Two tanks of gas and no high reving!!