highEasy 30 minutes–3 hours (DIY or shop) Community experience2,404 views
Source: Widely reported by owners. Not a GM statement. Confirm with a qualified technician.
When to stop driving
Pull over and turn the engine off if the temperature gauge reaches the red or you see a high temperature warning. Don't open the coolant cap while hot.
Symptoms
- Temperature rises in traffic but drops when moving
- Fans don't run when the engine is hot
- A/C blows warm at idle
- Only one fan runs
Likely causes
- Failed fan relay
- Worn fan motor
- Bad coolant temperature sensor
- Blown fuse or wiring problem
- Low coolant
What to check
Diagnostic steps, in order. Stop if any step needs tools or skills you don't have.
- 1Check the coolant level when cool.
- 2Turn on the A/C and see if the fans run. On many cars, the A/C triggers the fans.
- 3Check fuses and swap a fan relay with a matching one to test.
- 4Listen and look for fans that run slowly or not at all.
- 5Have a shop check the temperature sensor and fan wiring.
Possible solutions
- Replace failed relays or fuses
- Replace the fan motor or fan assembly
- Replace the coolant temperature sensor
- Repair wiring
Parts commonly needed
- Fan relays
- Fan motor or assembly
- Coolant temperature sensor
- Fuses
Warning signs
- Gauge creeping up at idle
- Fans louder or noisier than before
- A/C cooling poorly at idle
Prevention
- Check fan operation regularly
- Keep coolant fresh
- Keep the radiator and condenser clear of debris
Information here combines factory data and owner experience and may not apply to your exact car. For brakes, steering, suspension, fuel or anything safety-critical, consult a qualified mechanic. Read the full disclaimer.
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