I've been lucky so far with problems on my 2000 Magna TJ. Ironically while helping a mate with his broken down car mine started to play up too.

We had been tracing back an ignition problem on his car, using my battery to rule battery issues out.
So here I was letting my car idle to relearn gears and setting up my audio, until my mate noticed my car pissing out coolant.

Turned off the car and had a look in the engine bay. It was super hot, coolant came out the dipstick area next to the fuse box. Waited for it to cool, then turned the car on and checked:
- Thermo Fan (passenger side) not working at all. Not even in conjunction with air con fan.
- Air Con Fan (Drivers Side) works normally
- checked both fan fuses; 20A and 40A. They're fine
- swapped over fan and air con relays multiple times. They all work.

I'm pretty sure thermostat is gone, it shows a constant reading of half way and never changes.

I've read here that sometimes it's the Coolant Temp Sensor going bad.

Is there anything I'm missing?

I needed to replace that thermo on my 1999 TH last year as well.

I think they are just one of those things that die.

I'm pretty sure thermostat is gone, it shows a constant reading of half way and never changes.


Isn't that what a WORKING thermostat does normally? Unless it does so as soon as you turn the ignition on with a cold engine.

Signs of a crook thermostat:
Permanently open: Slow for the temp needle to move, where it points depends on air temperature and how hard the engine works. High fuel consumption.
Permanently shut, partially or fully: Temp rises too high, comes down if the fans kick in or you take it easy.
Normal: Goes up to half way after about 2 km from cold. Stays there no matter what.

I'd be tempted to pull out the non working fan and put 12 volts on it to see if it spins up.

The needle didn't go further than halfway while all the coolant came out the engine bay. That's what strikes me as odd.

The fan itself is workin, I just tested it. Pulled the sensor plug and the fans went on.

The fan itself is workin, I just tested it. Pulled the sensor plug and the fans went on.

Sounds like you'll need a new sensor for starters then... you may still have a bad thermostat though. At least thermostats aren't that expensive - don't know about the sensor.

I just hope it's not the computer. ;)

The needle didn't go further than halfway while all the coolant came out the engine bay. That's what strikes me as odd.

The fan itself is workin, I just tested it. Pulled the sensor plug and the fans went on.

I'd start by replacing the radiator cap, probably not holding pressure - or there may be dirt in it - when it releases too early coolant shoots into the overflow tank and squirts out onto the ground.

"The fan itself is workin, I just tested it. Pulled the sensor plug and the fans went on. "

It sounds as if the electrical connections in teh plug you pluued are crappy. Clean them up and you will probably be OK.

I'd start by replacing the radiator cap, probably not holding pressure - or there may be dirt in it - when it releases too early coolant shoots into the overflow tank and squirts out onto the ground.

Legendary. Didn't even think of that. Replaced the cap, which was pretty feral looking and gave the sensors a good clean while i was at it. And everything is back to normal.