GolfGTIforum.co.uk
Model specific boards => Golf mk7 => Topic started by: willni on 21 December 2021, 14:27
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Hoping someone could shed some light on this issue.
My heater started to blow cold air lasts night when it’s set at 21 degrees, which to me is fairly warm. I removed the silica bag when I got the car at 4k miles and that was 6k miles ago. When i removed it it was all fully intact so I’m struggling to think what it could be.
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A nightmare, I dread this happening.
Have you run an OBD scan to see if anything shows up?
Only from prior forum postings, I have seen the first point to check is the heater matrix under the dash in front of the gear lever.
If you still have warranty running, it's not so much your problem?
Are the pipes or pipe warm going into the heater matrix?
Maybe flush out and refill the cooling system as a starting point.
If pipe is warm and heater matrix is still cold maybe it is clogged.....
Let's hope it was, but was that the original coolant tank you took the silica bag out of?
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Could also be an issue with item 15. Heater support pump or 17. Coolant shut off valve??
(https://i.postimg.cc/9QBX5gRm/Screenshot-from-2021-12-21-15-28-17.png) (https://postimages.org/)
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If you turn it up to max heat does it blow hot, I know mine when it gets up to temperature it blows cooler air do keep it at temp selected
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First thing to try is a climate flap reset before doing any needless work.
Press and hold the AC button and the button for the air to come out the middle vents until they start flashing. It will make a few noises ans the flaps cycle and see if that helps.
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I hadn't used my heating over the summer and when I first started to use it few months back had the same issue. I to had thoughts of blocked heater marrix but after a few weeks it seemed to sort itself and now all seems to be working.
It's still not a patch on my wife's 4 year old Polo's heater, virtually instant heat and would put you out of the car if turned full up.
Plus the Polo's bonnet release feels so solid and positive unlike the Golf's.
Wished they'd fitted all similar in the Golf.
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Cheers folks, I'll run a VCDs log and do a Climate Flap reset later on and report back. It seemed to be working better last night, I have a temperature laser gun somewhere so I'll add that into the mix to be more precise than "That feels colder/warmer"
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Update, VCDs Log shows no issues with the car except low voltage to the headlights for some reason, I've performed the Climate Flap Reset so will let you know later if it has worked when the car heats up.
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My Clubsport has expansion tank 5Q0 121 507 G and upon closer inspection has the dreaded tea-bag.
I mean, had a dreaded tea bag.
10 mins later and it's out, fortunately no signs of tears to the bag.
(https://i.postimg.cc/W1PG4Vwb/20211222-112600.jpg) (https://postimg.cc/xctJsWZW)
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I find the heating on this car to be a bit erratic and it often feels too cool. Unless it's my age of course! My B6 Audi rarely needed to be set over 21c, then I got my PP which needed to be on 22c, this one often needs to be on 23 and is regularly on 24.
Hopefully the 'flap reset' will work, I had to change an actuator in my Audi as it had failed and was only allowing air out of one set of vents so could easily be the hot air input stuck closed.
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Have to agree with Watts, my A4 B7 heater was scalding hot and didn't need to be set as high as 23/25, yet my Golf is set to 25° and is nowhere near as hot.
I think it has something to do with the right hand air duct behind the dash not being adequately insulated and "loses" the heat on its way to to the vent.
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I'd be much the same, set it at 24 until the car heats up then drop it down to 19-21. In the mk5 golf I'd never venture over 21 degrees it was like a hair dryer, and the heated seats you needn't lean forward :grin:
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mine was the same last year in winter I wouldn't heat up I had the heater matrix reverse flushed it was manky lol. works a treat now
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Thanks for the advice everyone, the Climate Flap Reset fixed it and now it's a toasty 21 degrees and not 17 degrees pretending it's 21 :smiley:
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How do you reset the flaps Will??
Do you need VCDS??
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How do you reset the flaps Will??
Do you need VCDS??
No I used Finglonga's method:
First thing to try is a climate flap reset before doing any needless work.
Press and hold the AC button and the button for the air to come out your top vents until they start flashing.
It will make a few noises and the flaps cycle and see if that helps.
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Like this?? -
https://youtu.be/KJhaL65HL9Q
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Yep that's it, much easier to see than explain.
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Glad the reset seems to have done the trick. :smiley:
Got me worried so that's why I checked for the silica bag, as it's something I've been meaning to do.
For anyone who's interested in checking to see if there's a bag in the expansion tank, its difficult to see until you actually syphon the antifreeze out the expansion tank, then you can see it in the top left.
I clamped off the bottom feed pipe just in case the bag split whilst trying to get it out.
Gonna try the reset in the morning for no other reason than to make sure mines correct.
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Hello all,
thought I'd revive this thread, as I have the same issue.
I tried a flap reset and hot air only comes out on the vent nearest the passenger door. If I close the vent, some heat come to the middle 2 vents, but none to the drivers side.
Would this be blocked heater matrix perhaps?
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Started my car a couple of days ago to defrost it and it was bowing luke warm at best so did a VCDS scan. Sods law now is that my "Heater support pump" is showing open circuit and I need to have a look at it. Never happens in the Summer does it. :grin:
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Aux pump replaced and old one was completely dead but still only luke warm air so Heater Matrix replaced as well and it is now like a furnace.
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Hello all,
thought I'd revive this thread, as I have the same issue.
I tried a flap reset and hot air only comes out on the vent nearest the passenger door. If I close the vent, some heat come to the middle 2 vents, but none to the drivers side.
Would this be blocked heater matrix perhaps?
Did you ever manage to resolve this mate?
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That's so funny, as no I did not, then forgot about it, then today it's not blowing hot again.
I found this thread via google, forgot I had even asked this question, and did a flap reset and it no better.
So will need to investigate further!
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I scanned with OBDEleven, two faults!
(https://i.postimg.cc/3rZxyDb1/temp-Imageyg6lj-G.avif) (https://postimages.org/)
any advice guys?
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That is the same code I had P16C1 00 - Open Circuit and replacing the Aux pump fixed it.
When you turn the car off can you hear the pump running still, should run for around 5mnuites after shutdown to cool the Turbo. I noticed mine was silent when shut off and that is why I did VCDS scan.
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Thanks @Finglonga.
I haven't heard that, but I will check.
Did you have also not hot air in the car too?
Can I ask how much it cost to get to changed, Stealer or independent garage?
Do you know the exact part they replaced?
Looking back I see you had heater matrix replaced too, was that pricey?
Cheers!
That is the same code I had P16C1 00 - Open Circuit and replacing the Aux pump fixed it.
When you turn the car off can you hear the pump running still, should run for around 5mnuites after shutdown to cool the Turbo. I noticed mine was silent when shut off and that is why I did VCDS scan.
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Dupe post
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I noticed a couple of weeks ago that the heater was blowing colder air coming from the right centre and drivers side vents. From posts on the forum I started doing the climate flap reset procedure everytime I was driving the car and it seems to have worked, the vents are giving more heat now.
Might be worth repeating the reset over and over more times.
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Thanks @Finglonga.
I haven't heard that, but I will check.
Did you have also not hot air in the car too?
Can I ask how much it cost to get to changed, Stealer or independent garage?
Do you know the exact part they replaced?
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Went to independent as MUCH cheaper, he uses only Genuine VW parts, the heater was blowing cold. Replaced the pump and it was slightly better. The heater Matrix was then replaced and it was like a furnace. Can be replaced without taking the dash out as well if you use a good mechanic.
I would check with the VIN for the exact part as sometimes VW revise the parts. As for the price,not a clue sorry.
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Thanks very much.
Garage already mentioned it’s a dash out job for matrix, so I guess to need to find a better garage.
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Only need to remove the Glove box and it can be done from there. There was a video on Youtube showing how it was done. Last thing you want is the dash out as it can introduce all sorts of rattles.
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Finglonga is correct, no need to remove the dash, the heater matrix can be replaced without the dash having to be removed.
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Thanks all.
An independent specialist VW garage has quoted me £1100 inc vat for a labour and parts for a new heater matrix and heater support pump using genuine VW parts. I got the parts cost down a bit, still looking at £980.
Found this great video of how to do it...
https://www.youtube.com/watch?v=Yh8BwjJgkiI
I believe the matrix is either Valeo or Denso, available in UK from stealers for £366 inc vat or various sources for £200.
The heater support pump I believe is either Bosch and Pierburg, and around £70, or less from non VW sources.
I have found the parts on AutoDoc, much cheaper, but think they come from Germany, around £75 for matrix and £30 for pump.
So just thinking about if I want to tackle myself, anyone got any good parts sources recommendations?
cheers!
EDIT:
After some more digging, there is a Valeo official store on Amazon and the part is £75, bonkers!
https://www.amazon.co.uk/Valeo-715303-Heating/dp/B019IPPWZK/
It's £198 at Euros!
https://www.eurocarparts.com/p/valeo-heater-matrix-214440135
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Just get the pump done first as that may fix it 100% without the need for a Matrix and the extra cost.
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Thanks, I was thinking that, I found another video of someone doing it, seems straightforward.
However isn’t that pump meant for when you are parked with the engine off, I didn’t think it did much with the main heating system ?
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With it not working it can obstruct the flow to the Matrix I was told. It is to cool the Turbo by circulating water but remember it is also designed to keep the heater working on stop start cars when the engine is off.
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Thank, makes sense.
I fished the tea bag out yesterday and it wasn’t split, so hope it’s just the pump, not the matrix.
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Mine was the heater support pump, matrix was fine.
However the Right temperatures flap positioning motor makes a noise and doesn’t direct the warm air to drivers side, so having that replaced next!
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I had the right temperature flap motor replaced too today and reset with VCDS, has now finally solved my issue of no hot air, combined with the previous replaced heater support pump!
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UPDATE:
History so far, heater blowing intermittent cold air for ages.
Faults found with:
Heater support pump
Temperature flap positioning motor
Both replaced and faults cleared.
After above, it was blowing hot about 80% hot, but only on passenger side, drivers side was lukewarm warm at best, after engine running for 30 mins.
However took the car out early yesterday for 50 miles on motorway, it was -1 outside, and it never got as hot as when the above was fixed, barely warm.
On the way home in late evening it was 7 degrees outside and it got a little bit warmer, but not like it was after above two parts were replaced.
I keep thinking it is the matrix, but tea bag is has been removed and wasn't split, plus my mechanic says unlikely, as both pipes to the matrix are burning hot.
Rescanning again this morning and this fault has reappeared:
Activation A/C compressor
Fault code: B10A911
Just found this, might be pertinent:
https://static.nhtsa.gov/odi/tsbs/2014/SB-10070416-2280.pdf
I checked and I have AC firmware version 0805 and the newest is 1001
Answers on a postcard.... :laugh:
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My GTD from 2016 has FW 1001 (H03), but my GTI from 2018 has FW 1801 (H04); so obviously, 1001 is not the latest firmware. But someone else needs to advise how to update it...
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Thanks, I guess that service bulletin is old!
But wouldn't your 2018 car be a 7.5, might be different?
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Yes, 2018 GTI is Mk7.5 with firware 1801
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I've been thinking, it can't be the firmware, as it worked fine in my ownership for 7 years!
So it has to be something else, but I am at a loss to understand what.
Anyone else got any ideas?
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I'm thinking now that it might be the heater control valve:
https://www.vwvortex.com/threads/diy-coolant-shut-off-valve-n82-heat-taking-a-long-time-to-come-on.9493028/
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I or my mechanic still can't get the bottom of the issue, of the main heat coming out of passenger side, and it being like warm drivers side.
Found this today in the footwell, maybe it's fallen off something behind the dash?
(https://i.postimg.cc/P5PR3vZT/temp-Image-JNH2g-A.avif) (https://postimages.org/)
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That looks like the little cog on the glovebox arm that slows down it's opening.
I guess you or your mechanic have had the glove box swung all the way down as part of the investigation.
This cog can fall off if you don't unclip the arm properly before swinging it all the way down.
I would say you problem sounds a lot like an actuator problem.
If there is hot water at the matrix but not at the vents then I would think the control flaps that mix the hot air from the matrix with the cold air intake, to get the desired temp, and then distribute it are not effectively working.
Diagnostic scans will only show electrical problems with the actuators, if the actuator has become disconnected form the flap then it will move as per the electrical commands but the control flap will not.
Only my 2p worth, but hope it helps.
good luck!
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Thanks, yes I thought it might be from glovebox!
We already replaced the right temperature flap motor (VW part 5Q0907511K) and that stopped the clicking noise in the dash and cleared the fault.
Actuator sounds probable, but we can't see any issues with the other ones that are visible, so it must be deep in the dash. Hence we are a bit stumped about how to get to it, unless if you take about the headunit you can get to it? Anyone have an exploded view of the that area?
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Download the workshop manuals too see whats what behind the dash and how to take it all apart.
https://www.dropbox.com/scl/fi/9frg8zxrgde7cja32c4n1/2017-VW-Golf-GTI-Manuals.zip?rlkey=7dagos7l6rwnc1th7imk824i0&e=1&dl=0
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Thank you, very helpful!
Download the workshop manuals too see whats what behind the dash and how to take it all apart.
https://www.dropbox.com/scl/fi/9frg8zxrgde7cja32c4n1/2017-VW-Golf-GTI-Manuals.zip?rlkey=7dagos7l6rwnc1th7imk824i0&e=1&dl=0