2006 4.6 V8 overheating in winter only

[JacobB]

So my 06 Mountaineer has had a strange overheating problem for a while and i can’t tell if it’s a true sensor reading or not. This car is my every day daily driver and for the entire summer season, the car started and ran every day, taking 2 hour trips twice weekly without fail.

come the cold weather here recently in minnesota, the temp gauge has randomly spiked to the top of the gauge, then back down to operating temperature, one time engaging limp mode since i couldn’t find a place to pull over fast enough.

just yesterday i drove it two hours with no problems on the temp gauge. Without turning the car off i went into a drive-thru and it began to read hot on the gauge as soon as i pulled away. i pop the hood and i hear no boiling coolant or any signs of bad overheating. was able to touch most parts of the top of the engine bare hand.
my question is…is it a common problem for coolant sensors to go bad on the 4.6? or what could be causing the fluctuation in the gauge? if anyone has any good resources/diagrams for the coolant system that would be much appreciated.

 

[Turdle]

Assuming very cold temperature, could be a weak antifreeze mix freezing in radiator while driving. Not uncommon. You can test the mixture with a tester. They are usually available anywhere that sells antifreeze.

 

[JacobB]

Assuming very cold temperature, could be a weak antifreeze mix freezing in radiator while driving. Not uncommon

i’ve always used pre-diluted 50/50 from orileys, was about 5-15degreesF yesterday so could be possible.

 

[Turdle]

If coolant checks out, it may just be the thermostat picked a bad time to start sticking.

 

[D Hook]

Following this.