Buick Rainier Parking Heater Failure Fix Guide

I dealt with a similar heating system issue on my 2005 Buick Rendezvous last winter. I have some experience working on cars but leave complex repairs to professionals. The symptoms you describe sound very familiar. My car heater problems were traced to faulty glow plugs in the auxiliary heating system. The repair involved replacing the defective glow plug and running a full diagnostic on the climate control system. Total cost was around 440 for parts and labor. A few questions to better assist: Have you scanned for the specific error code? Does the temperature sensor show normal readings? When did you last have the heater core checked? Is there any unusual smell when using the heating system? These details would help determine if your issue matches what I experienced. While my Rendezvous had similar symptoms, different models can have unique quirks in their heating systems. Having this information would help narrow down whether you are facing the same glow plug problem or if it might be something else in the auxiliary heater assembly. The repair was fairly straightforward once properly diagnosed, but proper testing is crucial since heating system issues can stem from multiple components.

Thanks for your reply. Got it scanned yesterday and error code P0072 came up. Last service was just 3 weeks ago, but they didnt check the auxiliary heater since it wasnt giving trouble then. No weird smells from the ventilation system. The temperature sensor readings jump around a bit, sometimes normal, sometimes way off. The blower motor sounds normal though. Just checked under the car and noticed a small coolant leak near the heater core area. Not sure if thats related but might be worth mentioning. At 164134 KM, I guess these issues start popping up. Really hoping its just the glow plug like in your case and not something major with the entire heating system.

Thanks for those additional details, this definitely helps paint a clearer picture. The jumping temperature sensor readings combined with error code P0072 strongly suggest a temperature sensor malfunction in the climate control system, which is different from the glow plug issue I had. The coolant leak you spotted is concerning and could be related. When I had my heater problems fixed, the mechanic mentioned that leaks near the heater core can affect the whole heating system performance, including the auxiliary heater operation. In my case, the fix was straightforward because it was isolated to the glow plugs. Your situation sounds more complex with multiple potential issues: 1. Faulty temperature sensor 2. Possible heater core leak 3. Auxiliary heater malfunction Based on my experience with similar mileage on my Buick, I would recommend getting both the temperature sensor and the heater core checked first. The sensor is usually a cheaper fix, but that leak needs addressing before it causes more extensive damage to the heating system. The jumping sensor readings were not present in my case, which makes me think your issue might be different from the glow plug problem I encountered. Best to have a professional check the entire climate control system, especially with that coolant leak in the mix.

This seems a lot more complex than I initially thought. Good point about checking both the temperature sensor and heater core, makes sense to tackle both issues at once. Just called my regular shop and booked it in for next week. They quoted about 2 hours labor just for the diagnostic work on the heating system plus whatever parts are needed. The coolant leak has me worried, so better to get it sorted before winter hits full force. The ventilation system still works fine for now, but I dont want to risk bigger problems down the road. Will definitely have them do a complete check of the heat control components while its in there. Really appreciate you sharing your experience, even though my issue seems different from your glow plug situation. At least now I can go in better informed about what might need checking. Will update once I get the actual diagnosis and repair cost.