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GM Bob
GM Bob, ASE Master Technician
Category: GMC
Satisfied Customers: 1133
Experience:  30 plus years experience as GM technician, ASE Master Technician and GM Certified
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I have a 07 Yukon xl denali on dash it says engine hot turn

Customer Question

I have a 07 Yukon xl denali on dash it says engine hot turn off ac . well its winter .a new thermostat was put in and flush and new anti freeze. its saying engine hot turn off ac again .could there be bad new stat, air lock ,pluged hose??? it worked fine then going down road it did it again, temp gauge goes all the down from 210 whats up
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Submitted: 1 year ago.
Category: GMC
Expert:  GM Bob replied 1 year ago.

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.

Thank you

Expert:  GM Bob replied 1 year ago.

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If not let me know so I can continue to help.

Thank you