Low coolant light keeps coming on?

Robin Whitworth Statzer · January 6, 2017

Our 2001 Tahoe has a low coolant light that keeps coming on. We just had the head gaskets done, the radiator is only 2 years old (it's the 3rd one) and we just put in a new coolant reservoir. Any ideas why this keeps happening? We top off the reservoir and the light will stay off for a few weeks, but eventually comes back on. TIA!

Coby7 · January 6, 2017

When you replaced the tank did you replace the sensor? The surface of the sensor might be contaminated from the head gasket incident make sure the pick-up surface is clean. May need to soak it in vinegar for 10 minutes.

Robin Whitworth Statzer · January 6, 2017

According to the hubby when we put in a new reservoir tank it came with a new sensor (he had to attached a couple wires)?

Coby7 · January 6, 2017

Did he apply dielectric grease to the pins prior to installation?

Robin Whitworth Statzer · January 8, 2017

Thank you! He did not do the grease on the pins...that will be a next step...

Colossus · January 7, 2017

Ditto on the sensor. Have it tested. Even though it is newer, it can still have gone bad. Might need to hook up a GM Scan tool/Tech II to toggle the sensor or check the readings of that sensor via the Tech II, A good independent repair facility should have the tool. Probably save you some $$$ vs taking it to the stealership.