Hi,

 

I've got an Octavia II 2.0 FSI on a 55, and when I stop, there's a bubbling/gurgling noise from the expansion tank.

 

It's bubbling around the small pipe that feeds into the top of it, cautiously removing the filler didn't stop it, it just carried on bubbling and gradually stopped, no steam flying out and no suspicious smells like exhaust gas.

 

No overheating either, and the water level is about half way up the expansion tank.

 

Any ideas?

 

Thanks!

Iain

Sounds like it is thermastat or air lock is heater blowing hot air when upto temp.

Yes, air lock is one thought I had, I'll try the heater next time I'm out, as I bought the car only six weeks ago there hasn't been any need for the heater yet...

 

As it'll be going in for a service soon, I'll probably get the coolant changed anyway as it's a muddy brown colour

Had it serviced today, turns out it was a cracked coolant filler bottle