Had this problem since i bought the GT last december, but as it was winter, i didn't notice the disadvantages. However, now its summer (supposedly) it's become a bit of a bugger.......

Basically as far as i can remember, on my old Mk3, when the heater was set to cold, cold air came out of the vents aimed at the windscreen and the two aimed at the door windows, and when pointed to hot, hot air came from the same places. Whatever the setting, cold air would come from the adjustable vents.

What i have in my GT is hot air only from the windscreen/window vents and cold air only from the adjustable ones. I just read on another thread that this is normal?!!? If that is the case, then what is the point of the temperature control knob???!?!

Anyway, anyone know what could be wrong here? Cheers..

No idea what's causing it, but I get this too!

it's not normal, the knob should adjust the heat coming out of the top vents. you'll have to start taking the dash apart I guess and make sure the cable from the knob is ok and connected to the heater unit and that the flap inside this is ok

Sounds like the adjuster cable is broken, or the knob is broken where the cable connects - happened to me not long ago. To check, move the knob fully to one position and note what the valve on the passenger side of the heater blower thing is like. Turn the knob the other way and see if the valve moves. If not it's the cable! This could be fairly common as mine had been dodgily repaired once before where the back of the knob was bent.

Hope this helps!

I had a look at mine just now - the knob turns cleanly in both directions, and it pulls the cable through which pulls/pushes the arm on the valve/flap/paddle thing. Must be something else on mine. Where does the blower's cold air feed come from?

Edited 29 May, 200818 yr by steveeeee

Had a chat with my neighbour about this yesterday and he suggested that if the knob is definitely pulling the cable and adjusting the valve, maybe the valve itself is broken as the blower should only blow hot air if there's hot water in the heater matrix. So maybe the paddle inside the valve has broken, or maybe it's not closing all the way and the cable needs adjusting.

Apart from taking the pipe off and having a look at the valve, one way to check this would be to see if the heater matrix heats up with the temperature knob set to cold. I would've thought it'll pick up some heat just from being near the engine, but it should stay relatively cool. If it gets too hot, then water is being let through from the main cooling system.

I assume the blower pulls its cold air from the scuttle area? Which would probably get fairly warm when the engine's hot anyway, especially if the car's not moving?

Does this sound about right? Wiggy, have you had a chance to check your cable etc?

Any ideas? How are you getting on, Wiggy?

i have the heater blower motor out of my polo GT if its any good to you?

pm me if interested

Dan

I've found the problem! Difficult to explain, but the knob is attatched to a piece of metal, which is attatched to a cable which controls the temperature valve. (hope that makes sense...) The piece of metal on mine has snapped, so the knob still turns, but it doesn't move the cable.

Same happened to me, like monkey metal shit on the arm on the knob. New one from the scrappy sorted it.