2006 Hyundai Tucson temp gauge

Just had a new timing belt put in with water pump. Drove it home and the temp gauge flew up to red zone. Took it back they said air pocket in system. Bled the system. Drove home and same thing happened. Nothing changed. Temp gauge elevates past normal and into red zone when I idle or drive slow without air conditioning on. The weird thing if the air conditioning is on the gauge stays at normal longer.

What is the issue? Is it a bad water pump or thermostat? Or something else.

Thank you,

With the A/C on, the electric fan(s) are always running, providing more cooling. These same fans should start automatically when a certain temperature is reached. Check to see that the fan(s) are running when the gauge indicates an overheat condition… If they are not, sounds like the shop may have failed to connect a wire to a temperature sensor that controls the fans. Until the problem is resolved, run the A/C to avoid overheating the engine…I suspect that at highway speeds, there is no overheating problem, correct?

Haven’t taken it on the highway yet. Engine fan is running I can hear it. I’ll have to check if the fan is running when the gauge increases. Worse time is when I’m stopped at a traffic light the gauge moves quickly up past normal into red zone. Thank you.

One more thing to do…With the engine cold, remove the radiator cap and check the fluid level. It should be full to the brim…At the same time, the fluid reservoir (overflow tank) should be 1/3 full.

That description describes a cooling fan issue in a very “textbook-symptoms” sort of a way. The fans obviously work and that’s why having the AC on matters. But the fans aren’t getting the signal to kick on when the coolant temp gets too high.

Makes sense cigroller. Coolant levels are perfect. Yesterday I drove 5 miles, no ac on, stopped at a traffic light for 40 seconds and the gauge immediately climbed to the red zone. I can hear the radiator fan–it makes a loud noise. Are there other fans? Also, what happened. Worked fine before it went into the shop why now is it an issue?

Thank you!

My cars have two radiator fans. Make sure both are running (visually).

Thank you insightful. Happened again. Stopped at a traffic light and right up to the red zone. I had to shut the car off to cool it down. No a/c on.

It looks like your Tucson just has one fan. At this last episode, did you hear the fan running?