I did all the flushing, cap, thermostat, 50/50 antifreeze, etc, fixes but when I floor it going up an on ramp on an 85 degree day it will go into limp mode / fail safe mode. Bottom hose?

 

This with the new sensor?? Or have you not replaced it yet?

 

No, I haven't replaced it. I never could find out which one it was and where it was.

 

Follow this thread.

https://www.ford-trucks.com/forums/1...l#post12287801

 

There was only one post and the link led me back to here. I know there are 2 but not where the one responsible for it is. I saw a post somewhere that said it was under the intake manifold and hard to get out without removing the manifold.

 

I found this:

The CHT sensor has two wires to it, Gray/Red and Yellow/Light Green.... its located near the t-stat housing ... see pic below



Cut from my Ford Service Manual:

Cylinder Head Temperature (CHT) Sensor
Removal and Installation

1. Remove the upper intake manifold.

2. Remove the cylinder head temperature (CHT) sensor.
A. Disconnect the electrical connector.
B. Remove the CHT sensor.

3. To install, reverse the removal procedure.

 

Thanks, I was hoping I wouldn't have to remove the manifold. I was reading another post where he avoided removing the manifold. I will take a look at it.

 

*slaps forehead* Brent, I made that post for YOU in the V10 forum. Although, now I see rla2005 has squared you away with the info.

You need to change/check that sensor or you can just keep having the same issues you're having now. Up to you.

 

If the sensor doesn't fix it, there were a few people a few years back where the PCM was the faulty bit.

If you have a datalogger, have it log the CHT and coolant sensor, and see if the CHT goes wacky in comparison.

At some point, not sure when, I think the CHT was inferred from the coolant temp, or vice-versa, but that might have only been the 5.4...

 

Gotcha...thanks