Coolant error

[steve184]

This morning when i started my car, i got the red coolant error come in in my DIS. I immediately stopped and physically checked the coolant level under the bonnet and the level was where it should be. The error had cleared by the tie i had closed the bonnet and got back into the car.

Any ideas what this might be?

 

[BigBird]

Temporary airlock? Or the sensor probes on the expansion tank on their way out? This kept happening to me with my old Golf mk4.

A replacement expansion tank including the probes was under £20 & a cinch to fit. Cured the issue.

 

[steve184]

Do you have to replace the whole expansion tank? Presumably you have to drain the coolant system too and refill afterwards?

 

[c_w]

Trying putting a bit more in, mine has done this on and off recently but *seems* to have stopped when I went beyond the tank seam.

 

[BigBird]

Do you have to replace the whole expansion tank? Presumably you have to drain the coolant system too and refill afterwards?

The tank comes complete with the probes built in. I just lowered the coolant level by removing any fluid in the old expansion tank with a syringe, then swapped the tanks over and topped the fluid back up. Really easy.

This obviously came after a few weeks of getting the DIS message and checking the fluid levels all the time.

 

[steve184]

Trying putting a bit more in, mine has done this on and off recently but *seems* to have stopped when I went beyond the tank seam.

Bit odd - why would it think the level was too low - if it was indeed between the markings where it should be - don't want to overfill it as this can cause leaks to develop can't it?

 

[c_w]

I know - it may be coincidence but it hasn't come on again, I filled it up to 3/4 with some anti freeze.

 

[Baffles]

Had the same issue a few weeks ago - Audi ended up replacing the coolant bottle and sensor as they were faulty.

 

[mikejclark]

I read on another post to scrape the prongs inside the tank with a screw driver. it seems a build up of something on the metal breaks the circuit fooling it into thinking there is no coolant. worked for me anyhow

 

[dantdi]

Had this problem myself this morning. so just cleaned contacts on probes.
Hope thats sorted it.

 

[Virdee]

As many have said you can clean the contacts or replace with new tank to cure the problem. New tank ain't that expensive anyway. Circa £25. Plus you get the added bonus of a clear new bottle!

 

[Silky-S3]

I used to get this every winter with my old A3, only when it was cold. I think its just a sensor error/being slow due to the cold. Never happened when warm.