I recently flushed the cooling system (part of the 90k service) and drove the truck for about 100 or so miles with no problems. It had been sitting outside for a week and when I started it this morning the coolant sensor light came onand the truck would not warm up at all (ambient temp 18deg). No coolant loss, coolant is flowing in to the overflow tank.

Air pocket or thermostat stuck open?? or ??

thanks

Kevin

 

Did you bleed the air after changing the fluid, does your heater blow hot air at an idle, if not you need to do a bleed process so you don't overheat the engine. By the way, a new t/stat would be good at your mileage if it hasn't been replaced. What coolant did you use?

 

Mike:
Thought I had gotten the air out by running the truck with the heat on at idle on a level surface and then opening the bleed screw to let the air out. I drove it with heat on for about 100 miles with no issues (and heat). Is that the proper bleed process? Why does the "overheat light" come on when the engine is stone cold after 10-15 minutes of idling (no heat at all)??
thanks;
Kevin

 

Could just be a bad temp sensor.

 

Mike
Is the bleed technique ok?

 

Update:

Seems that the problem was a thermostat stuck open. Last night the truck warmed up nicely, but the gauge refused to register, light still on. Then 5 minutes into a drive the gauge suddenly snapped to the mid range position and light off. Worked fine today. Will change the Thermostat this weekend.

 

Back to your question, bleed it the way I suggested, doing it 2 times over a day or two.