strange heater characteristics

[gazjones]

now that the cold weather is hear ive noticed something strange about my heater. when i have the heater on hi to warm myself up and im driving along its fine lovely and hot but if i coast for a bit and let the engine idle it goes alot cooler, did think it was the engine cooling down during coasting. but i even does this when stationary so i have to verly lightly blip the throttle then full warmth comes back.
any ideas why id does this as the engine cant cool down that fast, only think i can think is if the heater is on full and engine is idling the water pump is not pumping fast enough to meet the demand of the heater.
cheers gaz

 

[richardcupra]

Just noticed that mine is doing the exact same thing, asked one of our techs and he said it does that so when idling the car isnt putting fumes into the cabin.

 

[pine]

I have similar probablems("manual climatronic"): during summer it could suddenly star heating, when it's supposed to cool and now when heating, I get cool breezes one's in a while. VAG/SEAT tech said that the little motors that move the linkage etc. are broken or kind of 'missfire'. Need to changed..haven't done it yet, waiting to either freeze to during winter or get the heat-treatment next summer..

 

[rashcupra]

try bleeding your coolant system as air locks can cause the heaters to under acheive hot?warm air!

 

[gazjones]

thing is its ben serviced in last 2 months that should have been checked i would have thought worth a try though think ill ask seat if its normal

 

[rashcupra]

chances are coolant has been changed and not bled properly maybe apprentice worked on it?

 

[BIGAR]

only think i can think is if the heater is on full and engine is idling the water pump is not pumping fast enough to meet the demand of the heater.
cheers gaz

That's right mate the water is pushed around the system via the water pump when you are on low revs the water pump is pumping at a slower rate, all cars have experience the same to a lessor/greater degree, its when you can get no heat in that's when you should start $hittin it.

 

[BIGAR]

Just noticed that mine is doing the exact same thing, asked one of our techs and he said it does that so when idling the car isnt putting fumes into the cabin.

sounds like a typical technician, has he finished his YT placement yet.

 

[mexicorich]

Make sure you are not actually low on coolant!

 

[moditsteve]

i have a similar prob sometimes say i have it set to 21 it is warm but other times at the same temp its blowing out Cool air ?? very confusing (and yes this is when the car is warm lol ) i just turn theheaters up to compensate for the cool air coming in

 

[rashcupra]

moditsteve and gazjones have either of you tryed bleeding the coolant system?

 

[gazjones]

no not bothered to, wasnt as bad today

 

[rashcupra]

lol! could be your answer if it keeps playing up when you turn all your fans off do you still get air coming thro the faster i go the harder it gets its so annoying!!

 

[gazjones]

no fans are ok its just the loss of heat on idle

 

[rashcupra]

yer i know just i have this problem where when i turn the fans off they dont

 

[moditsteve]

how do u go about bleeding the coolant system ? thanks