Yo! Done a search, but can find exactly what Im looking for.
While driving home just before, I relised my temp-gauge was creeping past half, I got home and noticed that the radiator overflow bottle was boiling! And spilling water onto the drive-way. I noticed the fans wernt kicking in either, but these were replaced not so long ago.

I just checked it now, and the radiator is full of coolant, and the overflow bottle is on the "Full Line"? Weird.
I replaced the water pump last week aswell as the WP Belt, any of this be a factor??

Im thinking maybe a blocked hose? Or a new Radiator Cap?

Any help guys would be appreciatedl.

is your thermastat opening? I had an issue in my old car where the thermostat was sticking a bit and caused the car to get hot, might not be an issue with magnas so take it as general info

No fans = boil

Do they come on with the aircon and if so does the temp drop

The relays in these are crap, get yourself some first gen relays and try them

turn your AC on, and see if the fans come on.

if they dont, its a relay somewhere, or bummed fans.

if they do, turn the ac off, let it warm up to about half way, maybe more. feel the top tube and the top of the radiator. does it feel hot?

maybe the thermostat (drivers side of the intake manifold) is not opening. when the engine gets to operating temp, this is meant to open to pass water through.

also try this: with the car cold, take the radiator cap off, and turn the car on. keep an eye on the temperatures, as well as the coolant in the top of the radiator. if the coolant doesnt move at all when the car is warmed up, chances are its a thermostat...

yeah, if i turn on the aircon, the fans will work, but they will not kick in themselves when they are supposed too.

yeah, if i turn on the aircon, the fans will work, but they will not kick in themselves when they are supposed too.

then its either the thermo fan switch or the relay that controls the fans. I've had both go on me on separate occasions, i just ran aircon until i could get it to my mech and have it fixed. If you're more mechanically minded than me though, that's all you'll need to replace :)

1) Relay
2) Thermostat
3) Faulty Fan Motors
4) Faulty temp sensor

Check the fan relays. Sometimes relays sick.

er, I meant sometimes relays stick. haha

My Magna's all went through his too. The fans didn't come on under normal load but there was water on the ground, radiator was full or near too, but the car was not overheating till water level in radiator had dropped a bit more.
I fixed the problem with a new radiator cap and replaced the expansion tank cap and seal.
I replaced the radiator cap first and it slowed the water loss, but where the condition of the expansion seal was cracked and fractured, it was not allowing water to be drawn back to the radiator when it cooled. So, everytime it got driven and more so on hot days, more coolant went to the expansion tank until the tank overflowed leaving water / coolant on ground ( also my daughter overfilled her tank thinking it was the washer bottle). By not drawing back to radiator, the level eventually fell below operational requirements, allowing the temp to rise.
Could be worth a check on that little plastic cap and seal, cost me thirty odd dollars for three of them ( well we got 3 magna's in this household :nuts: ) and they are the complete unit, siphon cap and seal.
It fixed all three magna's here anyway :D Hope this might help you out.

Cheers,