Marcus,

Sounds to me very much to me like a blocked radiator. I had a similar thing on my Pug 106 when i first bought it, although i was lucky and there was still half the radiator working so i could just magage to get about without cooking the engine.

Next step is to drain the coolant and give the rad a good flush through with a garden hose (remove top and bottom hoses). If it's bad you may need to back flush it by putting the hose in at the bottom and somehow sealing it so the rad fills and the water spills out the top.

When you re-fill the system make sure the heater is on Hot and you open all the bleed screws, i've never worked on a Polo so i'm afraid I can't help with their locations, but usually they're on the heater matrix pipes and any other high points. Make sure you use anti-freeze at a ratio of 50/50 with water. Once the system is full, run the engine at idle with the expasion cap off until the Radiator fan cuts in and turns off again, keeping an eye on the coolant level all the time, if there is any air in the system it will go down, also keep an eye on the temperature gauge, if it gets too high switch off and re-bleed the system.

Hopefully this'll sort it, if not you'll have to dig a bit deeper!

Let us know how you get on!

Good Luck

Chris

I think the answer lies in fact the cooling fan is not working could have something to do with it don't you think.

The other cause is that you could have blown the head gasget by running to hot the first time and over the next couple of weeks the problem has got worse.

Very common on these are the water pump impellers. They're plastic and they break over time. So it could well be the the coolant is not circulating and as a result your engine will overheat. If you've not had a new cambelt in a while it might be worth doing it and have the water pump changed at the same time.....