notcoldenough

I got my Mk 4 (a 1.5L TSI SE Tech) last September but it's only now the weather is hot that I've noticed the air con doesn't seem to be working properly - it's blowing a gale and making a racket but very little is coming out any of the vents even turned up full blast, and after it's been on a few seconds there's a loud clunk like a flap closing. I know you could recalibrate the flaps on the older models, there are plenty of youtube videos for the Mk 3 and it sounds like it would solve the problem, but I can't find a way to do it. Any ideas please? Photo shows the display/menu in the model I have, not sure if all the Mk 4 have the same one.