(help heater problem )

bokbok · Post by **bokbok** » Sat Aug 26, 2006 11:09 pm

i just got my g40 today but it does not blow cold air ?? when i put the fan on 1 2 or 3 it works fine but if i turn the hot to cold knob it stays the same warm air. is it the heater martrix ??? or the hot and cold knob f**ked ? thanks

SpikeyG40 · Post by **SpikeyG40** » Sun Aug 27, 2006 3:26 pm

mine does this occasionally. after a little while though it seems to change to how it should be!

Might be worth checking that there is no air in the system. there is a small bleed tap on the heater matrix under the scuttle cover, this is meant to be blead when the anit freeze is changed, if its not they usually get an air lock and i think this stops the system from working properly!

hope thats of some help!

pettsy · Post by **pettsy** » Sun Aug 27, 2006 5:25 pm

Just to point out that warm air won't actually come out of the main air vents either side of the dashboard if thats where you've been checking? It only comes out of the screen vents,the small vents just above the vents either side of the dash and the floor mounted vents.

Pettsy

bokbok · Post by **bokbok** » Sun Aug 27, 2006 7:35 pm

yes it comes out of the little vents not the big ones, but as i have noticed today it does not want to go cold it does what it wants when it is warm air it wont go cold and then some times it blows cold when the engine is fully warmed up and i want warm air ??? any ideas lads

Coops · Post by **Coops** » Sun Sep 24, 2006 1:45 am

cud be a heater matrix issue? can be a common problem in other cars? not sure bout polos cuz am just learning!

Tahrey1043 · Post by **Tahrey1043** » Sun Sep 24, 2006 6:58 pm

it's controlled by some kind of wire arrangement (like the clutch, throttle, or a set of bicycle brakes) that could be a potential troublespot - it had gone a bit funny on mine by the time i sold it (after i had the dash apart replacing the radio aerial) and stuck slightly halfway & wouldn't turn the full distance to cold, but still worked fine. yours may have become disconnected or snapped (it seems the system puts tension on the wire to go from hot to cold, and the spring is at the business end rather than the knob).

if there's hot air coming out of ALL the vents though, something more fundamental is screwed up. The "face" vents NEVER blow hot by design, their air feed (supposedly) bypasses the heater matrix.

bokbok · Post by **bokbok** » Mon Sep 25, 2006 9:48 pm

i sorted one problem and got another ?? i changed the thermostate and bleed the matrix and it has been blowing red hot air and running fine but when i try to put it on cold its still hot air and idea,s ??cheers

edjohnson · Post by **edjohnson** » Thu Oct 19, 2006 11:35 am

Er, the cold air comes from the large vents under the hot vents, there the FRESH AIR VENTS. You need to move the round slider round and you will have plenty of said cold air.

No Car Yet · Post by **No Car Yet** » Thu Oct 19, 2006 11:59 am

there is a falt don`t go buy a new 1 jus keep trying it

No Car Yet · Post by **No Car Yet** » Thu Oct 19, 2006 12:00 pm

there is a falt don`t go buy a new 1 jus keep trying it

minis84 · Post by **minis84** » Tue Oct 24, 2006 11:19 am

You will never get *cold* air from a Mk3 heater even if you turn it to cold.

All the cold knob does is close the valve on the heater matrix, meaning hot coolant is stoppped from going into the matrix. The coolant still in the matrix will cool down due to the air being blown through it (exactly like a radiator), however it won't get much colder than normal ambient temperature.

Your best bet for cold air (as already said), are the fresh air vents in either side of the dash, these basically feed straight from the plenum chamber and will always give nice fresh air.

Keep your heater on hot, it'll help with the cooling of the engine as well.

blighty · Post by **blighty** » Wed Dec 27, 2006 2:45 pm

i have similar problem, all i get is clod air coming from my air vents (the adjustable ones) although i get warm air from the static ones, which heat the window up. any ideas? lol

minis84 · Post by **minis84** » Wed Dec 27, 2006 4:19 pm

try reading my previous reply above yours!!

blighty · Post by **blighty** » Wed Dec 27, 2006 4:45 pm

that doesnt make any sense to me, as i DONT get hot air, i ONLY get COLD air

minis84 · Post by **minis84** » Wed Dec 27, 2006 7:57 pm

the air coming through the adjustable vents is air at ambient atmospheric (outside) temperature, there's no way you can get hot air through those vents because they're connected straight to the plenum chamber via the heater blower, but not via the matrix.

The small vents just above the adjustable vents, the windscreen vents, and the feet vents are all fed by air from the blower which has first passed through the heater matrix, hence they blow warm air, and the adjustable ones don't.

My personal preference is to have the heater on number 1, halfway between the screen and my feet to keep things warm, and then the drivers side adjustable vent fully open to provide a nice bit of cool breeze to keep me awake - works really well! Obviously in the hot summer the air coming through the adjustable vents will be warmer as the outside temperature is warmer!