Temperature gauge

[lee3671987]

Hi all

I've got a slight issue with my jzx100 temperature gauge (factory), it's started moving up and down while driving. It would reach red bar in 5 seconds and then randomly dropped half way.
This only happens during low speed or idling.
However i don't think it's overheating as I've been driving it for days now without showing any signs of overheats.
I've also checked if there's no leak anywhere and the coolant is all topped up.
I was thinking of replacing the thermostat tomorrow, does anyone else have other suggestion?

[woggin]

sounds like air in the system, tried burping the system?? unlikely to be cap/thermostat, but never hurts to replace it!! could b a contact issue one the sensor

[jondee86]

If the gauge is working correctly, the needle should not fluctuate rapidly. There is enough thermal inertia in the sensor housing to slow down the sensors reaction to temperature variations, and the needle will move quite slowly. If the needle flicks quickly between random readings (moving as quickly as it does when you turn the ignition off), then it is an electrical fault. Try tightening up the sensor wire where it clips onto the sensor, and if that doesn't help, try another sensor.

Cheers... jondee86

[lee3671987]

all good now, it was air in the cooling system....after i bleed the radiator temperature is back to normal again, thanks guys