No heat, no AC at 50,000 miles
More times than I can recall I read about how all modern BMWs have cooling system issues. I was convinced I was going to be replacing the water pump on the 335 but it never happened. The cooling system never crossed my mind on the Buick until Charlotte got home and informed me the cooling fans kept running after she turned off the car. They were still running when I went out to the garage to see what was going on.
After doing some research I found the thermostat is a common failure on the LGX v6 engine in the Regal. I like to monitor issues like this to ensure it is repeatable. It took some time for it to happen again and by then we were into winter so I was hopeful it would work well enough until spring when we had other cars out for the summer to drive while the Buick went under the knife.
The issue slowly kept getting more frequent and then started triggering a check engine light that required that be cleared then it would be fine for a week or two again.
Fortunately the issue stayed manageable until spring. The thermostat is buried in the valley of the engine so to replace it you have to drain the coolant, remove the intake, throttle body, intake manifold, loosen coolant crossover tube, along with assorted wires and small coolant hoses.
The fuel mixture is rich when coolant is low so pulled a plug to make sure it looked good.
Really buried in there.
New thermostat on the left, original on the right. It appears something in the coolant got stuck to the old one which presumably is what is making it stick. I never put dexcool back into cars when I drain it, always refill with the all makes and models yellow stuff. Hopefully that solves the issue for good.
With the new thermostat installed and everything put back everything worked as expected again…except for the AC. As the title says and I mention in the clip above, the AC was also not working. I attempted to troubleshoot that but was stopped in my tracks when I realized the Regal uses the new 1234yf refrigerant. I only have tools for R134a AC systems. So we dropped the car off at the neighborhood repair shop. They found the refrigerant charge was low so they recharged it. Hopefully that resolves the issue for a good while, but it obviously leaked for a reason so I expect it will need to be recharged again and eventually fixed.
I don’t normally post about normal car repairs but I found it interesting (and disappointing) that both the cooling (and heat) system and AC system had issues in only 50,000 miles so I thought I’d share.
