Hey everyone,

so last year around October or November my car started to randomly overheat if I stay still or drive at a low speed (10-40 MPH). When I went to check to see if my fans turned on they never did although, when I ran the IPDM test they turn on Low & High. I’ve changed the ECT, control module, gutted the thermostat, Changed water pump, burped the system, & wired the fans to run full blast through switch but she’s still overheating.

A couple days ago I ordered a CSF performance radiator & I’m going to get some new fans just in case because this really doesn’t make sense. my question is… has anyone had this problem before ? How did you solve it ?

(I hope this doesn’t matter but I also did a VR30 trans swap with a trans oil cooler)

 

Do you have an IR Gun? Can you confirm you are actually overheating? Could be a bad temp sensor.

If you run the AC Max cold when moving slowly does it still overheat? Fans should be on.

 

No i don’t have an IR Gun. I know that it’s overheating because I had to change my bleeder screw due to it being too hot and it snapped in half. I already changed the ECT maybe I should get an OEM sensor ?

Yes, even if I blast my A/C it’s blows hot air on 60 while I move slowly and starts to overheat. When I start driving a constant 60 MPH or over it blows super cold and ECT stays between 183 & 187 Degrees Fahrenheit. I wired my fans to blow full blast to eliminate the fans from being the culprit.

 

Did you check that the radiator and condenser fins are not clogged? Over time, dirt, bugs, road debris can accumulate and clog the fins which can hinder air flow/ heat rejection.

 

I had a similar issue with an old impala, I replaced the thermostat and thought I burped the coolant system.
Turned out there were still a ton of air pockets inside.

I ended up burping it again by starting with a cold engine and using a spill proof funnel.
Open the windows, get out of the car and crank the heat to max, let the car idle until the heat inside the cabin is as hot as possible. Even if the coolant gauge reads operating temp, keep the car idling with your funnel full of coolant.
Dont bother opening any of the bleed screws, just keep topping off with OEM blue coolant.