Heater Not working Properly

[jakroyd11733]

Hi,
I have made the venture in to the Audi owners elite and i have an issue with my heater.
I have a 2004 A4 B6 S line with climate control/air con style heater.
My issue is, it wont blow hot air and also i cant change the direction of the air... it only blows out of the 'face' vents (ones in the dash, 2 in the middle, one on each side by the windows). At this time of year not being able to de-mist the screen is starting to get frustrating.
I have looked across some threads and i can see that there have been issues with blocked heater matrix and also the actuator motors which may be the route cause of my issues..... I removed the glovebox last night and gained access to the motors / motor arms on the passenger side
Before i go and start ripping things to pieces to much can any one offer me come advise on the following:-
1. What motor / Arm operates what? - i have a green arm, a red arm and also a motor in the middle which looks to be straight onto a flap?
2. Are there more motors on the Drivers side which could also be an issue?
3. What motor operates the Hot/Cold valve / where is this located? (of not answered in point 1)
4. Does anyone have a wiring diagram for the heater system so i can check out the feeds etc.

Thanks

[mikeybutch]

The cold air is likely to be a failed thermostat.Check the pipes to the bulkhead.If the both get hot/warm quickly then it might be the matrix which is a bigger job but vigourous back flushing might help but not the best weather for that.It seems unlikely that all the flap motors are stuck.Start with the green one which is for the demister.New ones are expensive.I regreased mine 2ys ago and it still works but I move it regularly which seems to help.There are guides for this.THere is a central flap to regulate the heat intake which you can reach to feel if it moves but it seems that motor is more reliable perhaps cos the heat stops the grease hardening.Finally I wonder if there is a fuse for all the motors which may be why they are all stuck

[jakroyd11733]

Hi,
Thabks for the reply.
I have got the motors working now in the passenger footwell. The demister on (green arm) was seized solid. Took it off cleaned it and replaced it. All seems good. Also did the other 2 while I was there.
I still cant get hot air though. .. I removed the outlet pipe from the heater matrix (under the bonnet) no water coming out at all... seems I need to do a matrix flush 😣. I'll do that this week and see how I get on! Fingers crossed.

Problem I think I now have is... After rebuilding the motors I don't think the flaps are going through their full travel. Is it possible I have rebuilt them wrong and the sensors are now out (fully open and fully closed) - can anyone help me on this one??

Also, I removed the centre motor which had a wheel on it and 2 grooves which operates 2 arms simultaneous to operate the opening and closing of the centre vents.... I moved the arms to make sure there were free and also cleaned the motor... can anone advise the correct setup for its motor too???
What position should each arm be in when the ventire button is off?


Thanks
Joe

[mikeybutch]

Setting the motors can be done with VCDS otherwise its trial and error.Good luck with the matrix try flushing both ways it does work sometimes

[jakroyd11733]

Hi.
Forgive my ignorance.... what is VCDS??
Also where can I get this from?
Thanks

[mikeybutch]

This is the diagnostics cable that checks all VAG cars.If you cant access one you need to do some fiddling with the settings

[Crasher]

Heater matrix blockage on these is very common, thankfully not too difficult to change. I have never had any success trying to flush them out.

[jakroyd11733]

Hi,
What sort of a job is it to change in the case it is irreparable?

Also... to do the reset on heater flaps will the Vag com lite version be ok or do I need the expensive version? 😮
Thanks
Joe

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[Crasher]

VCDS Lite won't do Basic Settings.

The matrix slides out (just) and back in (just), make sure you use a new fitting kit or it ****** boiling water all over your feet!

http://i222.photobucket.com/albums/dd20/Crasher1964/8Ematrix2001-2008_zps012a93c5.jpg (http://s222.photobucket.com/user/Crasher1964/media/8Ematrix2001-2008_zps012a93c5.jpg.html)

[jakroyd11733]

VCDS Lite won't do Basic Settings.

The matrix slides out (just) and back in (just), make sure you use a new fitting kit or it ****** boiling water all over your feet!

http://i222.photobucket.com/albums/dd20/Crasher1964/8Ematrix2001-2008_zps012a93c5.jpg (http://s222.photobucket.com/user/Crasher1964/media/8Ematrix2001-2008_zps012a93c5.jpg.html)
Is that picture from the drivers side footwell??

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[Crasher]

Yes, the pedal box makes it close to being impossible to get out but with a little "persuasion" it can be tilted down and scraped past then back the other way.

[Teflon Shoulder]

I have got the motors working now in the passenger footwell.

There's another motor (yellow arm) on the drivers side that controls the heat for some of the outlets. It's a pain to remove unless you like being upside down in the footwell.

[jakroyd11733]

There's another motor (yellow arm) on the drivers side that controls the heat for some of the outlets. It's a pain to remove unless you like being upside down in the footwell.
Thanks.

I will have a look under the drivers side and see if everything is operating ok

With no watwr coming out of the heater matrix outlet I am guessing this will be my issue... fingers crossed I can clean it out... If not it sound like a PITA jon to change!!!

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[jakroyd11733]

Good evening all....
I have played about with some of the motors ad also removed the heater matrix pipes and flushed it out... I seem to be getting water now through the matrix now...
My only concern is there is nothing the unless you rev it to around 2500 revs.
I think I have seen some forum posts saying that if you see this it is likely to be the water pump as they came with plastic fins on when new and can break up....
Anyone gt any thoughts on this before I start taking the front end to pieces.
Thanks

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[Crasher]

The matrix pipes will flow even if the core is blocked solid, it is an anti burst design, it is pointless trying to clean it.

[jakroyd11733]

The matrix pipes will flow even if the core is blocked solid, it is an anti burst design, it is pointless trying to clean it.
Why do you think there is no flow unless I rev it???
Water pump??
Thanks

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[Crasher]

That is how they are, the water pump is engine rev linked, not constant flow-it's deceptive.

[mikeybutch]

Probably cos the flow is still badly restricted .If the pump had failed it would soon overheat.Unless you can feel some real heat now its odds on that the matrix will have to come out.Some say they have flushed it but they must have caught it early and been lucky

[Crasher]

A couple of years ago I managed to get a bit of flow back for a bloke who simply couldn't afford to have a new matrix, I put some rad flush in and he took it away and after a week or so it started to produce some heat but it must have some flow to be able to get into the capillaries and work.

[jakroyd11733]

I can feel some heat but it is no means really hot as u woukd expect it to be.
It will do fo now.
Might have a go at the matrix after the winter has passed.
Thanks all for you help.

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[Crasher]

Might have a go at the matrix after the winter has passed

Que :confused: