Hello all!
I am new to the forum and would be greatly appreciated if someone could help me... I inherited my pops 2006 Lucerne CXL with over 140k miles. Now, it hasn’t been driven for like 4 months. When I drove it, it was working fine during the end of the winter month of January, 2019 and during the summer of the same year. Until this fall up to now, it overheats slowly upon cold start. It overheats, then the abs traction disables and the engine light comes on P1258.
So I pull over so I won’t overload it and damage it. I let it cool down for about 5 - 10 minutes... Then I drive away, the temp needle bounces back and fourth and the engine light turns off. One minute it overheats, the next it operates just fine (after stoping and driven around for a lil while). I’ve change the thermostat (3 times) and water pump but want to change the coolant level sensor but not sure if that would fix the problem. Also, after this coolant problem, just a lot of other items starting failing. Any help would be appreciated!!!

**Update**
Lately after stopping and going, it only overheats in slow traffic. But once I drive on the highway, the temp gauge slowly goes back to the middle.

Sounds like you may have a restricted radiator. We shoot the temperature of the inlet and outlet and see how much heat it'* removing.

I would check and see if the cooling fans are working

I tend to agree with BossHog39 ^^^^^^^ , sounds like cooling fans to me.

yeah I want to say the radiator as well but I have to do a flush on it in order for it to work

I wanna agree as well but the fans are both kicking on when needed. You can even hear it while the vehicle in motion. 🤷🏽‍♂️

Shouldn't be able to hear it while driving. They aren't that loud. Have you checked actually seen them running with your eyes?

well they are not that loud but I did see them both turn on while the hood was up.

Ah okay. Was it able to cool itself down and then turn the fans off at idle?

If so then next assuming the coolant is full you should do what carfixer007 recommended above ^^^^^^^ : check and see if the radiator is plugged up be checking the inlet and outlet temperatures.

the fan works fine! I am leaning more towards the radiator because that does makes sense with the flow restriction. Plus I’ve check the top hose with is boiling hot and the bottom is cool.