Hello everyone, this is my 1st time on this forum and i hope i can find my answer here. If i can't then i really think im doomed!

I'll give you a basic description of my problem and pray that everyone can help me!

I have a Skoda Octavia 02 Tdi , iv been driving it now for over a year and what's been happening recently is that i drive on average 70-75mph and the temperature guage from 90 (ie in the middle where it should be) will start moving towards 100 110 and carries on increasing. As soon as i put the heater on around 26, 28 Temp and the heater kicks in (blows warm air) then the car temperature guage goes back to 90, where it should be.

But then the problem doesnt stop there, soon after 5 maybe 10 and sometimes even less that than, my heater on 28 or 29 will Stop blowing warm air and it will start cold or normal air even though its sets to 29 or hi. Then the car temperature guage will start rising again from 90 and increase until 110 and 130.

Before when i kept fiddling around with the heater to make sure its working so that the temperature would go down the temperature guage was to a degree controlled and the car drivable.

But now suddenly the hot air has Completely stopped working. Just normal or cold air blows, whether im driving for 5, 15 or 40 minutes, long or short distance, i just get cold air. As such my temperature guage keeps going up until the dreaded red icon and sharp teeeeh noise comes up on the dashboard saying they car has overheated completely.

Im Sorry if this is in the worng area of the forums.

Please please help and guide me to the best solution. I recently changed the hazard switch as it kept giving a clicking noise and my indicators stopped working. Now thats fixed and this temperature problem really makes my car impossible to drive because its over heating!

Pls help thank you in advance for everything!

Guys, is this partly down to the Coolant Temperature Sensor?

i hope i can find my answer here. If i can't then i really think im doomed!

It sounds like a problem with your waterpomp or with the thermostaat. You are not doomed just go without hesitation to the garage or the dealer.

I'll vote for the waterpump

Sounds more like a thermostat.

I take it the car isn't an Octavia II then?

Thank you for the replies, the water pump was changed last year when i got the cambelt changed as well. So i dont know, do you think it could be the head gasket? or just a simple thermostat fix?

If your heater is not giving hot air ever then that would indicate gas in the cooling system and no coolant passing through the heater matrix. With the engine cold, start the car with the coolant cap off and see if you can spot any gas bubbles coming up through the coolant (sure fire head gasket leak). Is the car losing coolant? If not, then it could be simple air lock in the system - if it is then it is likely the head gasket gone.