Cooling system temp drops to 160?

2021 CHEVROLET COLORADO
116,000 MILES • 4WD • MANUAL
Avatar
JOCOBUCK
Sometimes my coolant temp drops to 160 and the ac stops working and the fan constantly runs. I disconnected the neg battery cable and it resets for a lil while. The sometimes I see the temp going towards 210 and I hear what sound like a knock and the upper radiator hose will be extremely tight and I have to burp it at the reservoir to get it back right
May 9, 2026 at 8:49 PM
Advertisement
Avatar
STRAILER
  • ✓ASE Certified Mechanic
  • 54,487 POSTS
  • ASE Certified Mechanic
This sounds like the engine coolant thermostat needs to be replaced which can close down the coolant flow. Here is the location for a 3.6 liter since you didn't say the size of the engine so you can swap it out, drain the coolant first and disconnect the battery. You will need to remove the intake manifold as well.
Image (Click to enlarge)
Professional Diagram for 2CarPros Members
Click here to log in and view diagram.
May 10, 2026 at 6:07 PM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.