Coolant temp sensor or expansion tank?

[MajorBrownEye]

Greetings!

Whilst I was out driving today, a warning light came on. It was orange on the right hand side of the dashboard and I can only describe it as looking like a motor, but not like the illustration in the handbook, which has like a spark or bolt of lightning going in to it. The handbook was no help, translated from Spanish it says "if it flashes there is an excess of contamination". It wasn't flashing. Hmmmmm.

I suppose I should say I have a 2004 1.9 TDI 90hp.

I pulled in to a workshop that was open and the guy hooked it up to the computer which told us the coolant temperature was too high, it wasn't. He diagnosed the sensor in the expansion tank, fiddled with the electrical connector and managed to cancel the warning. He advised changing the tank as a whole unit.

A quick glance on eBay shows a few of these but loads of temp sensors.

Does anybody have any experience of this? Do I need to change the whole tank or can I change the sensor only? Am I OK to ignore it until it comes up again?

All advice gratefully appreciated.

 

[747_727]

It's a water level senser in the expansion bottle. The 2 pins corrode and cause the red light on the temp gauge to come on. I don't know if they cause the other light to come on though. You can clean the pins with a small wire brush. But if the problem is temperature related it won't be anything to do with the senser in the tank.

 

[MajorBrownEye]

Nice one, thanks.

It's behaving at the moment, so I'll worry about it as and when it comes up again.

 

[gazz]

You may find the following site useful, it tells you quite a bit about the type of light that is displaying.
It is aa1car.com

Just type in engine check light on.