Cabin ventilation blowing hot not cold.

E

eddthezed

Member
Hello folks,

Apologies for joining the forum with a problem straight away

I have a 2015 2 litre folding hard-top Z4. E89 I believe (not good on bmw numbering )

With heater temperature control at minimum temperature, 16, hot air blowing out. Can't get cold air.
Air con off. Fans work okay. Same result with roof down.

Looking on line I can see plenty articles on other bmw models mentioning heater control valve as being a problem in this situation. Can't find the valve, if it exists on this model.

Would appreciate any assistance before I go to the Big Money Wallet dealership

Many thanks.
 
Is it actually heated air that's blowing out, or just the warm air from outside? My first guess would be that the A/C has failed in some way, maybe through a drop in pressure or a hole in the A/C heat exchanger. Kwik fit are pretty good with doing A/C regas - might be worth going there at a first attempt; they won't charge you if they can't make the air cooler!
 
Many thanks.

With air con on – Coolish air blowing out side vents and middle vents. However foot well and vents near key fob blowing out roasting hot air.

When air con was off, took roof down all vents blowing out hot air.

Air con was re-gassed, as recommended, when the car was two years old.
 
Many thanks for your response ronk.

Set to blue.

I had a look at the parts pictures on one of the on-line manuals. The whole set up looks quiet complex.
 
@ronk out of curiosity what does that wheel do.. I never even took notice of that, before till you pointed it out always used the left and right dials.
 
It bleeds hot or cold air to the vents - I tend to use it only when it gets very hot or very cold. More often when I remember !
 
I don't think there is a hot water valve on these cars, instead it works by actuators moving 'doors' or 'flaps' within the HVAC box to control where hot air and cold air goes.

It sounds like your problem is with one of these actuators not functioning correctly, hence hot air blowing where it shouldn't. If you plug a code reader in, it MIGHT tell you one has failed. Unfortunately you'll likely have to pull a lot of the interior apart to get at any of them.

This should show all the different actuators;
http://www.realoem.com/bmw/enUS/showparts?id=LM72-EUR-10-2009-E89-BMW-Z4_35i&diagId=64_1709
 
Many thanks for your post Player 1.

From research I’ve done, I’m in agreement with you.

I popped in to visit an independent bmw specialist. He put me in touch with the person who does his diagnostic investigation. He also talked about flaps, motors/actuators.

Car booked in for Monday.
 
Car now fixed.

The car was put through the diagnostics. It threw up quite a number of errors that related to the ventilation system. eg blending-flap motor.left, blending-flap motor.right, fresh-air/recirculated air-flap motor,
defrosting-flap motor, footwell-flap motor, ventilation-flap motor.

He reset the complete car system and also the ventilation system.

He then turned his attention to the car battery. Diagnosis was that the battery was not looking good and was on its way out. He mentioned that in such situations the engine starting battery drain could be sufficient to lower the voltage enough to upset many systems on the car. Hence the battery was probably the initial cause of the problem.

With the heating/ventilation system now working okay it wasn’t necessary to pull the dashboard apart to get at everything. This would have been the next step and not the easiest of jobs.

Anyway, battery replaced, wallet emptied, but all systems looking okay now. :D
 
Hey guys, I'm having similar issues with e89 35i. The car blows hot air when it fully warm. The problem was present right since I've bought it, but in summers it's quite annoying. No errors sadly in IHKA (climate control) module. Yesterday checked with my laptop and a thermometer: when it's 22 Celsius outside, but the car blows 40 degrees hot hair. I've checked the flaps by pressing the buttons and saw their level change in the tool. The evaporator temp is 40 degrees as well, why could it be? Does anybody has any other idea, what could be the problem?

IMG_0849 (1).jpgIMG_0851 (1).jpg
 
eddthezed said:
Car now fixed.

The car was put through the diagnostics. It threw up quite a number of errors that related to the ventilation system. eg blending-flap motor.left, blending-flap motor.right, fresh-air/recirculated air-flap motor,
defrosting-flap motor, footwell-flap motor, ventilation-flap motor.

He reset the complete car system and also the ventilation system.

He then turned his attention to the car battery. Diagnosis was that the battery was not looking good and was on its way out. He mentioned that in such situations the engine starting battery drain could be sufficient to lower the voltage enough to upset many systems on the car. Hence the battery was probably the initial cause of the problem.

With the heating/ventilation system now working okay it wasn’t necessary to pull the dashboard apart to get at everything. This would have been the next step and not the easiest of jobs.

Anyway, battery replaced, wallet emptied, but all systems looking okay now. :D
Click to expand...
Above account has saved me a lot of time (and money!). Having searched for heater control valve in engine bay of UK spec 2012 2.8i E89 I realised there wasn't one. Quick look on here, and bearing in mind starting hasn't been great this week, I bought and fitted a new battery today and everything's back to normal; thanks edd.
 
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