View Full Version : Ventilation fans
Dizzy Ibizzy
30-03-2004, 16:29
Being new on here this is probably considered an old chestnut but any advise would be apreciated. My one year old Ibiza TDi Sport is due for service in the next few weeks and I beleive there is a problem with the heating / ventilation / climate control. When reverse gear is selected the ventilation fans turn themselves up to full blast, select forward gear and the fan returns to its setting. Is this a common problem that I should ask to be rectified at service ?
Apart from that, I love driving it, but the fan is sending me bonkers !
christdi
30-03-2004, 17:40
Mine does the same, I often wondered why that happens. Even when I have it turned up full blast to clear the windows, it always seems to blow much harder in reverse.
not to blow ya head round to see out the rear window is it :p lol
They all do it, though mine doesnt blow at full it just blows a bit harder than what I have it set at. As I understand it, it is to account for the fact that if you are going backwards there is reduced airflow into the system.
Yeh it must do it on all Ibizas with climate control as I experience the fan surge as well.
Just don't drive around for too long in reverse and it won't bother you!!!
Do you know Ive never noticed but then my fan goes up and down like a yo yo anyway seems to have a mind of its own. Somtimes when I stop at a junction it goes off for a second then comes back on I was hoping they are all like that.
On both of my MK4 Ibizas I have never noticed it. Then again I'm never in reverse long enough to think about what my fans are doing.
Welcome to the forum BTW! :)
If your talking about the Climatronic "semi-automatic" ventalation system it's on accont of not wanting to let you poisin yourselves with corbon monoxide as the air coming into the car when backing up can become mixed with your own exaust fumes! So the higher fan speeds you mention are simply the system momenteraly switching itself over to Recerculated Air! :thumbup:
muddyboots
31-03-2004, 11:45
Do you know Ive never noticed but then my fan goes up and down like a yo yo anyway seems to have a mind of its own. Somtimes when I stop at a junction it goes off for a second then comes back on I was hoping they are all like that.
Mine does this too, in warmer weather - did it all the time last summer but stopped as the temps got colder. Really bloody annoying, it's worst soon after startup and also when stopped at junctions etc.
I asked the dealer to investigate, but by that time it had stopped happening. When it starts again and I can demonstrate the problem I'll let them have another look.
I'm driving through Europe mid-summer so really don't want intermittent fans in that kind of heat.
Kind of good to know someone else has this problem....
The fan-speed-up-in-reverse is a standard feature - I posted about it ages back when I first got my car, no-one else had noticed until I pointed it out - then they couldn't stop noticing :p
Mine does the fan speed change during driving as well.
I thought I had it pinned to stopping for junctions but it does it on the move. The fan speed bars on the CC LCD don't change but the air-flow certainly drops.
IIRC, I asked Premier about it and they couldn't find anything wrong...
If you have it on Auto the fan speed changes along with the temperature.
When mine have been off auto they've always stayed at the same temperature and fan speed.
muddyboots
01-04-2004, 11:27
If you have it on Auto the fan speed changes along with the temperature.
Yes I know it should do that, but we're talking BIG fan speed changes (ie from off to fully on & vice-versa) every few seconds, whilst the fan speed bar graph remains unchanged.
I wonder if there are any sensor outputs that could be monitored with VAG-COM, to track down where the fault lies - anyone with VAGCOM care to have a look ? I suspect it could be an intermittent reading from a temp sensor.
Ralph & Chri5B -> Do yours have this problem all the time, or just in warmer weather like mine ?
Yes I know it should do that, but we're talking BIG fan speed changes (ie from off to fully on & vice-versa) every few seconds, whilst the fan speed bar graph remains unchanged.
Exactly what I see - no change in temp or fan speed bars on the display. It just cuts out and then goes again. Easiest to notice if you turn the stereo down a few notches.
I'm thinking it's more during the summer when it's working to cool rather than heat...
Dizzy Ibizzy
02-04-2004, 06:55
Thanks for all your replies, at least I'm certainly not alone with my bonkers ventilation fans ! It would be good if as mentioned someone could check via diagnostics if there is a heat / climate sensor problem, then when it goes in for service I can confidently ask for some sort of corrective action, or face the obvious ' They all do that sir' reply !! Thanks again. :)
Mine does it in summer the most although it has done it once or twice in winter and yes its big changes in fan speed it goes off then comes on flat out then slows down then off again then back on it does it for a while then settles down happens mostly when I stop at a junction for some reason.
muddyboots
06-04-2004, 11:25
I wonder if it's to do with the external temp sensor. The car manual says that the temp reading may be inaccurately high when the car is stood still, I think it gets affected by heat from the car/engine/exhaust/etc - and it seems to be in similar standstill circumstances that we get the on/off fan problems.
Anyone know where the external temp sensor is on the Mk4s ? Maybe the wiring is prone to getting damp or something.
If your talking about the Climatronic "semi-automatic" ventalation system it's on accont of not wanting to let you poisin yourselves with corbon monoxide as the air coming into the car when backing up can become mixed with your own exaust fumes! So the higher fan speeds you mention are simply the system momenteraly switching itself over to Recerculated Air! :thumbup:
This is the theory I've heard, too.
keebo_sioux
07-04-2004, 12:30
i only noticed this yesterday! It really surprised me!
I still can't get over the fact I don't have to do de-mist and de-ice the car myself at all - the windows clear in a second or two (the old mk2 took minutes)!
I wonder if it's to do with the external temp sensor. The car manual says that the temp reading may be inaccurately high when the car is stood still, I think it gets affected by heat from the car/engine/exhaust/etc - and it seems to be in similar standstill circumstances that we get the on/off fan problems.
Anyone know where the external temp sensor is on the Mk4s ? Maybe the wiring is prone to getting damp or something.
Pax side wing mirror (I think!)?
I'd swear mine does it whilst on the move though...
muddyboots
08-04-2004, 11:29
Pax side wing mirror (I think!)?
Flapper -> Any chance of confirming the MK4's ext temp sensor is in the pass mirror ?
heater wise if regulated air con theres 3 sensors
1 by the evaporator 1 inside in the passenger footwell and 1 in the fresh air intake duct
the actual temperature display sensor is same style as the Leon in the mk4 so more likely in the lower NS lower bumper grille area (will be a small dome like a round pencil rubber) with 3 small rectangle clips holding it in
as for the fan speed in reverse- IIRC its the recirc flap closing for fume blocking and sounds like its going faster but it is only slightly as its all blowing internally
try pressing recirc to see if it replicates the same noise
hope that helps
(ps - thanx for the message muddyB :p ) needed to test it
I realise that this Thread is over 2 months old now but my climatronic has just started doing the same. Switching off an dthen on again with no change to the display.
Has anyone had this repaired? If so what was wrong. My SEAT dealer connected the car to a computer this morning and surprise surprise found nothing!
Any pointers would be appreciated!
Thanks
I've noticed mine doing it now everyone's talked about it.
I'm sure it's normal and nothing to worry about.
Do any other VAG cars do this?
muddyboots
16-06-2004, 08:09
Yes mine's doing it fairly regularly now the weather's hotter.
Like last year it's mainly when slowing down/stopping, or on startup.
I assume that the fans should speed up a *bit* when you slow down, to counter the loss of airflow from outside.
But it goes bonkers full off - full on - full off for a while before settling down....
Nac1975 -> I also mentioned it to the dealer last year, they couldn't find anything wrong.
Yeah mine is the same, but I also found that when the weather was really cold and I pressed the demist button the fans didn't get to full speed for ages, although this only happened when the car had just been started. In hot weather the fan speed rises and falls for a few mins every now and than but generally its ok.
I have it several times that the display flickers. The dealer checked it out the other day and diagnosed that the fans to cool the aircon radiator were burnt out. When the display flicker it means that there is fault with the aircon.
Hope it helps.
Niall
mines started playing up again in the hot weather its not a problem as such its just annoying.
muddyboots
19-06-2004, 10:58
as for the fan speed in reverse- IIRC its the recirc flap closing for fume blocking and sounds like its going faster but it is only slightly as its all blowing internally
try pressing recirc to see if it replicates the same noise
Yep, you're right, putting the recirc on makes exactly the same noises as when you put it in reverse. The fan speeds doesn't change, you just hear more noise. Spot on !
With regards to the manic fan in hot weather, the display on mine never changes or flickers, unlike Nialls.