Water temp warning light and needle. Pls help

[Vin-R]

Hey guys,

Need your help please. Recently ive nocited that every now n then, my water temp needle drops from like 90 to about 75-80, then slooowly bringe itself back to 90. This has been happening for a few weeks now.

I checked coolant level and it was fine. However went on a long trip at the weekend, and went to start the car today, and the water temp WARNING light was flashing. Opened the bonnet to find that all the coolant has gone?????

How could this have happened?

Cheers

 

[Russler]

You need a new thermostat

 

[towcester vag]

diag check the temp sensor first these are common

 

[Vin-R]

Ok so a faulty temp sensor and thermostat would cause needle to drop an then back up??

Also would these faults cause the coolant level to just drop quickly. Because b4 the long journey at the weekend the level was fine. And this morning it was literally at MIN.

 

[LEE69]

Where as a the water gone?
Look for tell tale signs of crystallisation.

The temp gauge dancing like that is the stat.

 

[Vin-R]

Coolant was just just under the MAX level on saturday when i went to london from coventry.

This morning it was barely above minimum. And the RED WARNING light flashed up on the water temp gauge

Where would i look out for crystallisation?

Thnx

 

[LEE69]

On any coolant hose/join, pump might be leaking too, matrix can leak in the car

 

[Vin-R]

Hmmm ill have a look. In the mean time ill have to pick up some G12 coolant from TPS and top it up.