temp gauge says overheating but...

[whopper3155]

Just replaced the upper and lower thermostat housing along with the sensors because I had a coolant leak. Never had an overheating issue.

Now immediately as i crank up the truck... the temp gauge goes straight up, almost red-lined. takes less than 20 seconds.

On another thread, it was suggested to check the sensor connections... did that.

 

[shooterdude199]

its air in the system. same thing happened to my truck when i did my radiator. can't remember if it did it when i did the thermostat and housing.

 

[gtyates]

Yep, air in the system. I had the same problem on my daughters car when I replaced the coolant tank. To solve it park the truck with the front end slightly elevated, then open the radiator cap. Start the truck, turn heat to hot, then watch the air bubbles pop out of the radiator. Sounds crazy but it really works. When you stop seeing air bubbles it should be done. Might have to do it one more time a few days later.