Mechanics

SERVICE ENGINE SOON - COOLANT TEMP L

2001 Buick Park Avenue

Engine Cooling problem
2001 Buick Park Avenue 6 cyl Front Wheel Drive Automatic 115000 miles

Hi, the service engine soon light is on and I had AutoZone put their gizmo on to tell me what the code was. They said Coolant Temperature Low was the indication. Indeed, the temp used to hover in the 180s or higher but now it doesn't get much above 150. I opened the hood with the engine running and the electric radiator fans are on. Coolant level is fine. I haven't driven the car for a couple months, it had a bad front bearing, but this wasn't a problem until after leaving the garage with a new bearing. Any idea what it could be? I am suspecting that the computer controls the fans, and when it sensed the coolant temp not reaching setpoint, it locked the fans on to prevent overheating. Could this be as simple as a bad thermostat?

3/24/08 - Found the problem. Indeed the car is smarter than I gave credit for. When the computer sensed that the coolant temp never reached some setpoint, it decided that maybe the sensor was bad, and turned on the Service light and locked the cooling fans on to prevent overheating. I replaced the thermostat, reset the code, and it is running great, without the cooling fans (until they are needed)!
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Hookedonfishing
March 20, 2008.



Yes, the thermostat is the most common problem. Most people automatically replace the coolant temp sensor, but they rarely ever fail.

Dennyp
Mar 29, 2008.