Got the car back from the dealer... I was handed a TSB document, and like a child was given multiple printed pages about how a cooling system works. According to the TSB, our LUW engines are energy efficient, and doesn't "generate the same heat when compared to and older, less efficient engine." "Engine is slow to reach normal coolant operating temperatures should be considered as a normal operating condition".
PI1166C: Vehicle Slow to Heat Up in Cold Ambient Temperatures ? 2011-2015 Buick Chevrolet | gm.oemdtc.com
Condition/Concern
Some customers may comment in cold ambient temperatures on the following:
The engine is slow to reach normal coolant operating temperatures as indicated by the engine coolant temperature gauge.
The air coming out of the heater outlet ducts is not warm enough for their personal preferences.
The vehicle is not warm when using the Remote Vehicle Start feature.
Recommendation/Instructions
The energy efficient engines that these vehicle are equipped with may not generate the same amount of heat at idle that the customer may be accustomed to when compared to older less efficient engines. Additionally, depending on extreme cold ambient temperatures, a short drive cycle under light engine load may also not generate enough heat to reach normal engine coolant operating temperatures as indicated by the engine coolant temperature gauge and therefore insufficient heat from the heater outlet ducts.
Perform the Diagnostic System Check – Vehicle.
If any DTCs are set, Go to Diagnostic Trouble Code (DTC) List – Vehicle.
If no DTCs are set, Go to Step 2.
Verify the coolant in the radiator surge tank is at the correct level.
For vehicles with manual heater control or automatic control in manual mode, instruct the customer that during extreme cold ambient temperatures to place the blower on medium (3) instead of high (6) during vehicle warm-up or remote start. This will result in warmer outlet temperatures sooner. When the blower is operated on high speed (6) with extreme low ambient temperatures, the heater core will pull more heat out of the coolant than the engine can produce at idle or low speed causing the engine and outlet temperature to be slower to warm up.
Note: Automatic HVAC operated in Auto mode is already optimized for lower blower speed during engine warm-up.
DO NOT replace the engine coolant thermostat unless a DTC code is set related to the thermostat, as the ECM monitors the thermostat each key cycle to ensure it is operating within design parameters.
If there are no DTCs, the engine coolant level is correct and the thermostat is diagnosed as operating correctly, then the comment of the engine is slow to reach normal coolant operating temperatures should be considered as a normal operating condition of these energy efficient engines in cold ambient temperatures.
Customer Information
Please communicate to the customer that this condition as described is a normal operating characteristic of their vehicle. It will not impact the designed performance or reliability of the vehicle. Please share this information with the customer, including a copy of this information.
