I posted on another forum and haven't gotten far, thought I'd give a non-Chevy forum a try.
2016 Colorado, 2.5L WT with 6-speed
I have air in the cooling system and have been unsuccessful in removing.
There is a gurgle from the heater core and the temperature gauge regularly swings from normal to borderline overheating (240 °F).
What I've tried:
No matter what I try, I have the same symptoms- gurgle, cold lower hose, and fluctuating temperature.
Thoughts?
2016 Colorado, 2.5L WT with 6-speed
I have air in the cooling system and have been unsuccessful in removing.
There is a gurgle from the heater core and the temperature gauge regularly swings from normal to borderline overheating (240 °F).
- Heater core has the typical gurgle; the upper radiator hose is warm, the lower is cold (40 to 60 °F). This is a reverse flow system.
- I have heat.
- Temp gauge swings from normal to max. Double verified w/scan tool.
- New radiator cap.
- New thermostat.
- Pulled water pump, it's in good shape.
- Coolant system holds pressure @ 20 psi.
- Cylinder compression good (checking for head gasket issues).
- Pressurized coolant system and checked cylinders for misting w/endoscope. No problems.
- Good coolant color, oil is good, no white smoke from tailpipe.
- No loss in coolant.
- Electric thermostat has 12 V and 5 Hz pulse; removing it from the housing, it heats as it should.
- Radiator is ~4 months old.
What I've tried:
- Using a coolant fill kit.
- Filling on an incline using ramps.
- Vacuum bleeding kit.
- Vacuum bleed kit on an angle.
- Leaving ~1 inch fluid above reservoir seam.
- Warming up and checking for kinked hoses.
No matter what I try, I have the same symptoms- gurgle, cold lower hose, and fluctuating temperature.
Thoughts?