Failed cooling fan, relay or sensor
Electric fans are controlled by a temperature sensor and relay. Any of the three can fail. Turning on the A/C should make the fan run — if it doesn't, that's a strong clue.
Low coolant and leaks
Coolant leaks from hoses, the water pump or the radiator itself are common in Central Texas where 100°F summers stress plastic radiator tanks. Look for pink, green or orange puddles under the car.
What to do right now
If the gauge climbs in traffic on MoPac or I-35, turn off the A/C and turn the heater to full hot — this pulls heat from the engine. Pull over safely if it reaches the red. Never open a hot radiator cap.
Get it fixed by a mobile mechanic
Matt Mobile Mechanic of Austin handles this at your home anywhere around Austin:
Popular areas: Austin, Round Rock, Pflugerville, Cedar Park, Leander, Georgetown
Frequently Asked Questions
Can I add water instead of coolant?
In an emergency, yes, but have the system properly filled soon.
How much does a cooling fan replacement cost?
Typically $250–$700 depending on the vehicle.
Can overheating damage my engine?
Yes — continued driving can warp the cylinder head or blow the head gasket.