Temperature gauge suddenly drops to zero

[kiwi tonka]

I recently bought an A2 1.4 SE 2002 .Bought as i have always loved the A2, after previously owning an Audi 80 then an Audi A4 and this one has everything i wanted , from climate control , electric windows open sky sunroof & full black leather interior.After i bought it found out it was Battersea Audis demo (hence all the loaded extras).Has one minor problem with the temperature gauge going to the usual 90 degrees then suddenly drops back to zero whilst driving.Other times it rises to 60 degrees then slowly drops back down .I have been told it could be the Temperature Switch. Any ideas as its starting to annoy me.Especially when there's nothing else wrong with it .(Fuels going down fast with the car thinking its temperature is cold).Tempted to try to fix myself as Audi dealer would most likely charge me the earth for just thinking about how to repair it.

[spike]

Hi kiwi tonka, welcome to the A2oc
It's almost certain to be the temp sender. This happened to my car and I changed the thermostat first only to find it was the temp sender
See link for more details
http://www.a2oc.net/forum/showthread.php?t=4664&highlight=sender

Cheers Spike

[monkeyfinger]

Had exactly the same sypmtoms recently on my Passat, and I had to replace the temperature sensor.

[lyndonbuck]

Me too, the dealer repaired under warranty but they broke the thermostat while repairing it - had to wait a day while they ordered a new thermostat - so its probably worth getting both done at the same time. This seems to be a common problem with VWs and Audis