I'm Fffffffeeeezing!

C

copperband

Member
Hi,

First post and yet another one related to the mundane subject of the cabin Climate control.

I basically have no heat at all.
Temp reads 90.
Fans all flow and change direction according to the relevant button press.
Garage has checked it and said the fault code 710 is coming up that the heater flap positioning motor (v107) - blocked or no voltage
Also fault codes 727 and 601 potentiometer in positioning motor for defrost flap and central flap - open or short to plus (intermittent).

garage recommends that we start by changing the heater flap motor - part no: 6Q0 907 511 A https://www.ebay.co.uk/itm/232621787938?ViewItem=&item=232621787938

I'm hopeful it might just be this but also wondering if I should change the other motors too.

I am also not convinced that there climate control module itself is working correctly.
Reason I say this is because if I switch it to manual then often, if I change just the temp side, it also changes the fan speed after a few seconds or a bit longer. This would be expected if it was on Auto but not on manual where I would expect the change in temp to be independent of the fan speed?

Any thought or advice gratefully received.

Car is Blue Storm 1.6FSi
 
I have recently had the temperature control flap motor changed and all is well. If your existing motor cannot be freed by going up and down the temperature band on several occasions then you may need a knew one. The motor is accessed after removing the glove box and should take around an hour and a half to remove the old and fit the new. It does not require the removal of the dashboard as some garages may suggest.

The temp flap motor is black coloured and sits next to the positioning motor which is white coloured. If you feel the positioning motor is faulty then they are easily changed at the same time.

Please be wary of buying second hand on ebay... a used motor may suffer similar defects after many years of use.

Cheers

Dave:)
 
I would invest zero money and a bit of time to exercise the temperature flap.

On a journey with a passenger in the front, just ask them to switch the temperature to maximum and leave it for a second or two, then switch it to minimum heat and leave it for a second or two.

Exercising the flap has definitely worked for me on two cars so far, one wouldn't go cold and the other wouldn't go hot.

I tried the above and got instant results (well after several minutes of exercising it.
The other I exercised for almost an hour, then gave up, only for it to work perfectly the next morning and it stayed that way until I sold the car weeks later.

So before you take a hit on the cost of replacing it, it is worth trying the "no cost" option first.

Steve B
 
Thanks for the replies.
Birchall, I've done what you suggest already quite a few times as I hoped that it might respond to a little exercise.Alas not though.
The only time I have a little warmth back was when an Auto electrician started taking it all apart and said nothing was wrong with the flaps opening and closing, he believed it was a blocked heater matrix. He started taking the car apart and then advised me it was going to be 8 hours labour to get to the matrix and back again. I asked him to put the car back together and pay him for his time so far. In the process he found the expansion bottle was cracked and so he replaced it along with the cap and coolant. After he'd done that the car was warm for a few days?

Special edition, thats very helpful on which colour is which motor. I have actually removed the glove box, but such is my amateurish skills or car knowledge that I could actually work out where these motors are! I tried online to find a video showing me but had no luck.
I'm a bit torn on the ebay parts thing. On the one hand the part is likely to be 15 years old like the one coming off my car, on the other it's £10 - £20 vs £165 new from Audi!
 
Hi Copperband,

Just a minor point which will probably not matter. In your first post you quote a part number for the flap motor ending in A. Your eBay link part number ends in B. Check this out, but 7zap.com does not show B used on the A2 but only A and D (which goes to year 2008???). B might well be compatible but it would worry me.

Andy
 
Andrew said:
Hi Copperband,

Just a minor point which will probably not matter. In your first post you quote a part number for the flap motor ending in A. Your eBay link part number ends in B. Check this out, but 7zap.com does not show B used on the A2 but only A and D (which goes to year 2008???). B might well be compatible but it would worry me.

Andy
Click to expand...
Thanks Andy. I noticed that too on 7zap. Strangely they have a label for A, C and D and then one with no letter, but no B?! The dates also seem to be a little off. My garage says that the fitment is the same, most likely that the supplier of spec changed and hence the letters?
 
Hi,

there are two designs of flap motors used in the A2 and they are not interchangeable, both physically and electrically (the plug is a different shape).

During MY 2004, the design was changed so you need to check your VIN or the part number of the existing motor to make sure a replacement is the right one. The wrong one will simply not fit.

Both early and latter parts are shared with other VAG models (Polo and Fabia mainly) so should be readily available. The earlier design to my knowledge has not been superseded by a latter part. It is no-longer used on any current car and isn't in production. The latter part fitted in A2s has been discontinued. An alternative part is available new, but its a universal rather than an exact like for like replacement. The alternative part omits the lining up guide points on the gear that the original A2 specific part has. It will work fine but is slightly harder to fit.

The temperature control motor is designated V68. V107 as quoted in the original post is the one that turns the windscreen demist air on and off. The part number quoted 6Q0 907 511 A is for the earlier, pre 2004, V107 motor - the windscreen demist. If you have having temperature problems, I would not have thought that changing the windscreen demist motor would help.

For temperature problems I would think that the V68 motor ought to be looked at. This is 6Q0 907 511 for early cars. Note that a lot of the motor part numbers are very similar. That doesn't mean that the motors are interchangeable as each has a unique drive and fixing mechanism.

This post describes the climate control system and the various motors used:

https://www.a2oc.net/community/index.php?threads/anatomy-of-the-a2-climate-unit.25089/#post-197128

regards

Andrew
 
This extremely helpful, thanks for taking the time to write Andrew.
It confirms a few things. My car has the motors on the left of the pic so i must have the pre MY2004 motors. This makes sense as the car is 53 plate.
I took the glove box out this afternoon and tested a few things:
Recirculation flap functioned fine on the left.
On the right, when i pressed the button for the screen demist, the white cog turned fine.
When I dropped the temp from the lowest to the highest, the other flap also opened and closed.
the fan speed changed without me changing it which I thought was odd as the temp was not set to AUTO function?

So it seems the motors (assuming there are just those 3) are working as they should but the air is still very cold.

I am now back to thinking it's nothing to do with the motors and something else?
The auto electrician said he thought it was the head gasket over pressurising and thats why the expansion tank cap had split and lost all the fluid.
Following his fitting of a new one, the heating worked like a dream on the way home?
 
I think the fan speed is automatic on manual too. I'm sure mine has the fan at low speed when the engine is cold, picks up when it's warm enough to blow at 23.5 and then slows when the car warms. I always thought auto had to do with air distribution but I'm prepared to believe that mine is just bust.


Sent from my iPad using Tapatalk
 
If the flaps are ok then it could be either a blocked Heater matrix or even an air lock. Have you tried running the car for a while with the cap off? That might just free up the air lock if there is one.
Last resort is the sensor that determines the cabin temperature. But they can be tricky to change.
Steve B
 
Last edited:
Birchall said:
If the flaps are ok then it could be either a blocked Hester matrix or even an aur lock. Have you tried running the car for a while with the cap off? That might just free up the air lock if ther is one.
Last resort I’d the sensor that determines the cabin temperature. But they can be tricky to change.
Steve B
Click to expand...
When you say cap, do you mean the cap on the expansion tank?
 
Yes,

That allows a better circulation of the coolant and is one way to release an air lock.

If you can massage the pipes close to the heater matrix that might help.

But if you have been able to feel that the matrix is getting hot, then it is not an air lock anyway.

One other thing to check, not that it would make a lot of difference is the pollen filter that is under the glove box
That can become blocked with leaves and muck and so can restrict the air flow and hence reduce the heat output?

Clutching at straws, yes, but is not that easy to resolve unfortunately.

Steve B.
 
Unlikely to be a blocked heater matrix if it functioned correctly on the way home from the mechanic. Has the cap subsequently "blown"? Can't get my head round the mechanic's verdict of a leaking head gasket over pressurising coolant system being the problem. I would ask why this has stopped the cabin warming up? But the fact that it blew the cap is a problem in itself. Maybe Steve's suggestion of faulty cabin temperature sensor bears investigation.

Andy
 
I fear that the leaking head gasket is unlikely, there would be other symptoms, such as a creamy substance in or around the oil filler cap, over heating, lumpy tick-over signs of oil in the water etc.

Steve B
 
copperband said:
This extremely helpful, thanks for taking the time to write Andrew.
It confirms a few things. My car has the motors on the left of the pic so i must have the pre MY2004 motors. This makes sense as the car is 53 plate.
I took the glove box out this afternoon and tested a few things:
Recirculation flap functioned fine on the left.
On the right, when i pressed the button for the screen demist, the white cog turned fine.
When I dropped the temp from the lowest to the highest, the other flap also opened and closed.
the fan speed changed without me changing it which I thought was odd as the temp was not set to AUTO function?

So it seems the motors (assuming there are just those 3) are working as they should but the air is still very cold.

I am now back to thinking it's nothing to do with the motors and something else?
The auto electrician said he thought it was the head gasket over pressurising and thats why the expansion tank cap had split and lost all the fluid.
Following his fitting of a new one, the heating worked like a dream on the way home?
Click to expand...

Hi,

I have never quite understood Auto, its more to do with automatic air direction control than fan. Quite how it knows that the air should go to the windscreen or the face I don't know!

The fan speed is adjusted automatically so if the engine is cold but you want heat, it will keep the fan speed low until the engine warms up so cold air isn't blown in and increase if more heat (or cold) is needed in the cabin depending on the set temperature and actual temperature. The fan speed control buttons allow you to override the automatic fan speed setting.

It is common for a motor which has a fault for that to be vibration sensitive. The motor can work fine when tested with the car stationary but exhibit a fault when the car is moving and being shaken by the travel over the road. As the flaps are relatively fragile and the motors have a high torque output, if the climate control detects an issue with the motor or position sensor, it will switch off the motor immediately and it will remain off until the ignition is turned off and back on again. The prevents the motor from potentially destroying the flaps or linking mechanism if there is an obstruction or out of position gear. It means however that the flap will stay in the position where it was left when the motor was disabled. The flap isn't stuck, the climate unit has decided it doesn't want to move it. A common result of this is the cabin actually being too hot. If the motor works when the car is stationary, it will move the flap to the full heat position as the engine is cold. Once the car is moving, a fault is detected and the motor gets switched off. The flap never moves from this position. As a result, the delivered heat never gets backed off and you end up having to drive with the windows open in winter!

As you are getting cold air rather than hot air its probably not the motor. To rule out any air temperature sensor miss-reading, set heat to HI. When set to the HI position, the temperature flap will be on the full heat position regardless of any temperature readings. VCDS can also read the outputs from all the sensors to check for sensibility.

One thing you can check if you think there is a temperature sensor issue, the main cabin temperature is read by a sensor on the climate control panel. Its behind the grill you can see in the center above the buttons. For it to work correctly, there is a small fan motor that draws air through the grill and over the sensor. If the fan isn't turning then you may be getting a cabin temperature miss read (e.g. too high). Setting the heat control to HI will override this though. This fan runs all the time so could wear out or get bunged up with dirt, fluff, pet hairs etc.

regards

Andrew
 
Last edited:
So tried a few of your suggestions today.
I took the bonnet off the car and then the cap off the expansion bottle.
As I did that I noticed there was already a pink crust on the outside of the bottle. A bit odd, considering it was only replaced a few weeks ago?
Anyway, ran the car to warm up to 90 degrees and here are my observations:

The coolant level was constantly changing, it never went lower than the minimum level but would go up to Max and then beyond and overflow, it would then drain back to the min level again. This repeated in a cycle.

The cabin temp didn't change at all (stayed cold).
I changed the temp and the flaps moved as normal, although interestingly, when the cap was off the bottle the flaps only opened and shut at the opposite ends of the temp range. With the cap on the bottle, when I changed the temp it moved more gradually, within the temp range?

Outside the car and where the air intake is I noticed interestingly that the air here was a mix of cold and warm, it seemed to cycle a bit but there was definitely quite warm air when i put my hand into the air intake. I can't really work out why there would be any warm air there as it should be drawing air in right? Or does it draw outside air in and expel air too?

Either way the overflow tank behaviour was not what I expected and still nothing got warm inside the car?
 
Hi,

interesting symptoms. On the climate control front, the temperature flap will be all the way over to the full heat position when the engine is cold on all set temperatures other than "LO". If the gauge was showing 90 at the time however, it should not be doing this. However, the temperature sensor which the engine and other computers use to read the water temperature isn't the same one as used to run the gauge on the instrument panel. Sometimes one can break but the other is fine.

There is clearly something up with the coolant though. Either there is a blockage, caused by air or even a physical obstruction (e.g. dirt, sludge) or there is a problem with the water pump. Do you know when the water pump was last changed? The blades are made of plastic and can break off if the pump is old. If you have lost a few blades then the water flow will be poor, particualy when engine revs are low like idling. This would cause poor water flow, no heat in the cabin heater and the water boiling causing overpressure and coolant loss. Also engine damage if allowed to persist.

regards

Andrew
 
ajsellors said:
Hi,

interesting symptoms. On the climate control front, the temperature flap will be all the way over to the full heat position when the engine is cold on all set temperatures other than "LO". If the gauge was showing 90 at the time however, it should not be doing this. However, the temperature sensor which the engine and other computers use to read the water temperature isn't the same one as used to run the gauge on the instrument panel. Sometimes one can break but the other is fine.

There is clearly something up with the coolant though. Either there is a blockage, caused by air or even a physical obstruction (e.g. dirt, sludge) or there is a problem with the water pump. Do you know when the water pump was last changed? The blades are made of plastic and can break off if the pump is old. If you have lost a few blades then the water flow will be poor, particualy when engine revs are low like idling. This would cause poor water flow, no heat in the cabin heater and the water boiling causing overpressure and coolant loss. Also engine damage if allowed to persist.

regards

Andrew
Click to expand...
Thanks for those thoughts Andrew.
What’s your view on the warm air in the intake duct, is that normal?
 
Also and to answer your question about the water pump...this is actually quite interesting as the water pump was changed with the cam belt 3 months ago and it was straight after that work that the heating issue began.
 
copperband said:
Also and to answer your question about the water pump...this is actually quite interesting as the water pump was changed with the cam belt 3 months ago and it was straight after that work that the heating issue began.
Click to expand...
When changing the water pump it is easy to get air locks, so if it was fine before then I would suggest that may be what happened. But you have tried releasing the air lock without success.

Steve B
 
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