help needed,

[antz]

went out this morning to my car and started her fine , then al off a sudden the temp warning light comes on and i get a nig stop sigh flash up on the dah, have checked my coolent level and that seems fine, any ideas? ive switched the car of strait away to check but not sure what could be,

car is a mk4 gti 20v turbo v reg

hope you got some ideas peeps

[Rhyso]

sounds like a faulty sensor in the coolant tank - common problem

you can either try and clean up the prongs or get a new bottle from VW for no more than £15 

[antz]

is that the sensor on the out side of the tank? ive started the car back up and diconected teh sensor but it made no diff

noticed the stop also said check coolant wich i no the level is fine

[richw911]

is that the sensor on the out side of the tank? ive started the car back up and diconected teh sensor but it made no diff

noticed the stop also said check coolant wich i no the level is fine

As Rhys says 

Its the metal prongs inside the expansion tank. Get a new one from VW for around 10 pounds

1JO 121 403B 

[Rhyso]

is that the sensor on the out side of the tank? ive started the car back up and diconected teh sensor but it made no diff

noticed the stop also said check coolant wich i no the level is fine

disconnecting the sensor will tell the car there's a problem so its no use unplugging it

[Ant1981]

Open the tank, scrape the prongs with a screwdriver and job done. It's simply just a layer of corrosion on the prongs.