i asked this over on seatcupra.net but not having much luck
seem to have a strange heating issue. car warms up as usall no problems nice hot air then after around an hour of driving all of a sudden it goes cold. after another 10-15 mins it got hot again. im guessing i could have some air in the coolant system? anyone had this before?
I doubt air in the system would take an hour to materialise!
Are you using the 'auto' setting? Guessing you have a Seat - so I'm not 100% familiar with their HVAC controls - but basically, turn the heat setting to the max heat (HI on the Golf GTI with dual-zone climate, and the red blob on lesser spec 'climatronic' Golfs) - and leave it there. Because when you use anywhere between full hot or full cold (say 21degC on the heat setting) - the heater will blow out toasty hot air (once the engine coolant has been heated up) - and continue to blow toasty air until the cabin temperature reaches 21degC - then the air coming out of the vents will cool down. If, say you then happen to drive between some trees or in a hidden dip where the outside temperature can get noticeably cooler - suddenly toasty air will come out of the vents again.
HTH, and let us know how you get on.
