Buick Regal GS Overheating Tied to Grille Shutter Failure

I had a similar issue with my 2015 Buick LaCrosse Hybrid. Having some experience with thermal management systems in hybrids, I can share what worked for me. My car showed almost identical symptoms, overheating issues combined with the check engine light. After getting a diagnostic scan, the shop identified a defective electromechanism in the active grille shutter system. The flap motor wasnt responding properly, preventing proper airflow management to the cooling system. The repair cost came to 590 for parts and labor, which included replacing the faulty flap motor assembly. The repair solved both the overheating and check engine light issues. To better assist with your specific case, could you share: Current mileage on your Regal? Any other warning lights besides check engine? Does the overheating occur more during city driving or highway speeds? Have you noticed any coolant loss? These details would help determine if youre facing the same underlying issue. A proper diagnostic scan would be essential to confirm if its indeed the flap motor causing your cooling system problems.

Last service was at 121336 KM and the issues started shortly after. The overheating happens mostly in city driving, and yes, Ive noticed minor coolant loss. No additional warning lights beyond the check engine light. Recently checked the air intake system and everything appears clean, though the thermal management system still seems compromised. Getting it scanned later this week to confirm if its the grille shutter causing these cooling system problems.

Sounds very similar to what I experienced with my LaCrosse. The timing and symptoms match up, especially the city driving overheating and minor coolant loss pattern. When my flap motor started failing, it also caused the most issues during low-speed driving when airflow was more dependent on the active air flap functioning correctly. The mileage is also in the range where these thermal management components typically start showing wear. My diagnostic scan revealed fault codes related to the grille shutter position sensor, which was preventing proper cooling system operation. Based on your description of clean air intake but compromised cooling, Id bet youre dealing with the same flap motor issue I had. The active air flap control system is crucial for maintaining proper engine temperatures, particularly during city driving when natural airflow is limited. Once you get the diagnostic scan results, look specifically for codes related to the grille shutter system. If confirmed, the repair should be comparable to what I paid, and it should resolve both the car overheating and check engine light issues. Would be interested in hearing what the scan reveals. Keep in mind that continuing to drive with an improperly functioning thermal management system could lead to more serious issues.

Perfect timing on getting the car scanned this week. Thanks for detailing your LaCrosse repair experience, really helps knowing the fault codes pointed to the grille shutter position sensor in your case. The symptoms matching up, especially during city driving, makes me more confident its likely the same flap motor issue. The price point of 590 for the repair seems reasonable if thats what it takes to fix both problems. Will definitely get those specific thermal management codes checked during the diagnostic scan. Makes sense about the active air flap being extra important at low speeds when theres less natural airflow. Been limiting my city driving until this gets resolved to avoid any bigger issues. Will update once I get the scan results and confirm if its indeed the grille shutter system causing these cooling problems. The fact that your repair fully resolved similar symptoms gives me hope for a straightforward fix.