Water/coolant light

[magicdaps10]

In the last week my collant light has come on when i start the car.The light then goes off after about a minute and does not come on until i leave the car over night.

Its an Audi a3 1.9tdi 2005 plate.

Could it have anything to do with the cold weather kicking in?

p.s
There is water in there!

 

[RonS3]

It's a common problem which is easy to fix. The probe in the coolant tank become slightly corroded and it seems to be the cooler weather which exposes the problem more (not sure why) Take the cap off the tank, scrape the two probes with a knife or similar and the problem should dissapear. The probes pass a current between them through the water so you need to scape the sides closest to each other if you see what I mean. I've done this on a mk5 golf and an 8P A3, worked on both and hasn't come back on either for many months

 

[magicdaps10]

Cheers Ron and done what you said.

It only comes on in the morning and started on weekend when obviously the weather has got a tad colder.Will probably have to find out if the scrapping has done the job in the morning and hopefully no coolant light will come on!

Have read into it and it does as you say seem to be a common fault.Also read that a little top up of water will sort the problem so also put a teeny top up of water in the tank.

If it doesnt work then obviously i would say a new sensor is required?
Would you know if its a hard job and how much would a new sensor cost?

 

[RonS3]

I'm confident it will be gone in the morning, I don't think you can buy the sensor on it's own as it's part of the coolant reservoir.