Coolant Temperature Sensor

[Ridg]

right pretty sure my coolant temperature sensor has gone as the temp gauge is either at 0 (or whatever unmoved is), 90^o or decides to move from rest to 90 and back during the drive. eg its working then stops then works.

I've checked the Haynes and read up on how to change it, but can't quite see where it is, to check the connection / change it.

Also are there any implications of running the car with a broken temp sensor? as my next service is in 3K (about 10 weeks) so could i wait till till then?

[GarryR]

Don't think it will affect the running of the car, the only thing i was concerned about was if the engine overheated or i ended up with a leak in the coolant system. took it to my local mechanic who's a VW specialist and he replaced and fitted it for £26. not had a problem since!! 
This is a common fault but not too dear to fix.

[Ridg]

This is a common fault but not too dear to fix.

yeah i'd read that it was quite a common fault and that it can be as simple as corrosion on the plug that can be cleaned off, but can't find the bugger to clean it 

[kalu]

The temp sender is very easy to change, Just pop off the engine cover and look to the N/S of the cylinder head and you will see a coolant pipe. The sensor lives in that pipe, all you need to do is unplug it and and remove the securing clip. It will then pull out, be sure to have the new one ready with a new seal so you can quickly pull out the old one and push the new one in. This way you wont loose too much coolant.
Also before starting make sure the engine is not too hot and relieve any pressure in the cooling system by removing the cap.