have you checked the seal on the tank cap yet? If it's not sealing then it can cause the water to boil up, the pressure it what stops it boiling up all the time.

I never had this problem with my other engines on the same coolant bottle, the cap doesnt leak water or air from what i can tell.

My mate is coming round with a compression gauge soon, any ideas what sort of readings i should be getting? 1.6 ABU 1993.

it's still worth checking, takes like ten seconds and it will cause he exact symptoms you describe if it's not sealed, all it takes is for the cap to have gone on slightly wrong and the rubber seal not seated or flipped out of its seat.

Whats a good way of checking its sealing at high pressure?

mines the old black lid as well, the blue ones are meant to be better arn't they?

only other guess is it could've iced up - and broken something i suppose

mines the old black lid as well, the blue ones are meant to be better arn't they?

yes the older black ones are known for failing, quite common on golf engines too. Just remove the cap and look at the state of the rubber seal on it.

only other guess is it could've iced up - and broken something i suppose

Like what Pete?

I havn't tried to start it while its been icey with just water in there..

The small pipe on top the coolant bottle is flowing coolant back so the pump is working, going out to check the cap seal now. Fkin rain

i dunno mate... ice can break impellors, pop head gaskets, pipes, crack blocks etc

....No seal, where should it be? The inside or outside?

it goes around the inside circle, hard to tell from the picture but it looks like it's ok.

It should be here:

Ok i got a new cap from the different scrappers, that seems to have stopped the coolant boiling but the car keeps over heating!!

The car goes from 0 to 110 degrees in about 4 minutes even with the stat out!

But for some reason the fan isn't tripping on, the switch works and when turned on with a switch is does nothing to cool the engine!

The bottom rad hose is cool so the rad works but still the engine over heats?

Any ideas?

a blocked radiator perhaps?

water pump? one of my old polo's had a bit of sealant lodged in the return feed to the header tank.

if it's heating up that fast i'd say water pump. do the blowers blow hot?

I had the hose pipe in the top rad pipe and had it coming out of the top of the coolant bottle so doesn't appear to be any blockage.

Plus the bottom rad pipe is very cool.

But i actually took the water pump off and checked the impellers and the bearings and it was fine?

The top coolant bottle pipe is relaying water back so the pump must be working?

yes that should be fine then, i'm sure mine had two fine holes in the plastic water way.

do the heaters blow hot air?

The heaters are working fine, the temp needles moves pretty quick doesnt take long for it to get to 100+

but the bottom rad pipe never gets hots? And you've fluhed the actual rad through (water in top rad connection and it comes out the bottom ok)?

I took the top rad pipe off from the stat housing and put the hose pipe in there, it then started pissing water out from where the pipe was, so that suggests the rad isnt blocked doesnt it?

does the car show any signs of over heating apart from what is says on the gauge? tried a different set of clocks or different temp senders?

I only have these clocks hat i got today from the scrappers, the black sensor was fine in the AEE. Although the strange thing is, when the gauge gets to 110 the fan still hasn't kicked in? It has a new fan switch and the fan works. So could it be lieing to me?

does the car show any signs of over heating apart from what is says on the gauge? tried a different set of clocks or different temp senders?

stage 1 fan speed should kick in at 92 - 97 degrees,stage 2 at 99 - 105. i would say the actual fan has had it if the switches have been changed.try bridging the terminals to the fan switch,if the fan doesnt spin its fucked

Just been out, the gauge went up to 110 and then coolant came gushing out the bottle.

The exhaust manifold is glowing slightly as well... that might be the timing thats out though.