I have a 1998 1.4 CL Polo with 40K on the clock. Was having problems with poor starting and excessive petrol consumption (50 miles to £10 of petrol) The car was leaving sooty deposits in the drive after cold starting with strong smell of petrol. The temperature guage was also taking forever to get to normal operating temperature. This site suggested the coolant temperature sensor, but to be certain I would need the fault code. I tried a local garage with diagnostic tester but the tester came up with no faults found .

I went to the local VW dealer and got a price for the sensor which was £31 including VAT but before buying I went to the local scrapyard and got one out of another R reg polo for £2. Installed it in car which then ran perfectly with petrol consumption back to normal and no soot from exhaust.

Many thanks to the site. Hope this is helpfull.