GMC Troubleshooting Questions? Ask a Mechanic for Answers
Hello my name is ***** ***** I can help.
Are you setting a P0128 code?
Here are a few things that can cause this problem.
A faulty thermostat I have had to replace the twice. Make sure you are using GM thermostat.
I have had some coolant temp sensor have faulty reading when warming up.
After a radiator replacement. Some replacement radiators may be missing a restriction orifice that is built into the right side radiator tank. The restriction orifice is molded into the nipple that feeds the radiator surge tank.
The engine may not reach operating temperature, or set DTC P0128 due to excessive coolant flow to the radiator surge tank
Let me know if this helps.
Was this helpful?
If not let me know so I can continue to help.