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Aircon and heater doesn't work

Discussion in 'Leon Mk3 (2012-2020)' started by Scott_FR, Sep 3, 2016.

  1. Scott_FR

    Scott_FR Active Member

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    Since picking the car up, I noticed the aircon wasn't working. Hooked it up to VCDS and it tells me the gas pressure is too high. Hoping that will be a simple case of getting the system drained and refilled with the correct amount of gas.

    Decided I'd give the heater a go to see if that is working. Absolutely nothing! Absolutely no warmth whatsoever. Only thing I can think is that there is air in the heater matrix and it needs bled. But judging by the disgusting colour of the coolant (I guess this should be bright pink??), I doubt it's ever been drained.

    And as an added kick to the plums, it appears the previous owner decided to keep themselves warm on long journeys by chain smoking everywhere they went. I assume it was a driver and 4 passengers, all constantly chain smoking. Without doubt, the smelliest smokers car I have ever experienced! Removed the pollen filter... Could have rung the tar out of it! :censored:
     
  2. Scott_FR

    Scott_FR Active Member

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    Oops, forgot to ask the question... Are there any common faults on the 2.0tdi which would cause the heater to not work?
     
  3. dw911

    dw911 Active Member

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    I'm guessing you bought the car without seeing it or maybe you left your nose at home when viewing it ;)

    Has letting gas out the air con system fixed the fault? if not it's likely to be the sensor that measures the pressure in the system that's faulty

    Is the vcds not showing any fault codes for the heating system ?
    I'd say, assuming the fan works and you can get cold air, then it's probably more likely to be a fault with the a mixing valve or a valve that moves to direct hot air to the vents from the matrix, or maybe the valve that controls hot water to the heater matrix, assuming the Leon has such a valve.

    Normally if you have an airlock in the system, the whole system tends to overheat and read high on the temperature guage
     
  4. Scott_FR

    Scott_FR Active Member

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    I think the car must have had all doors left open before my arrival and given a major burst of air freshener immediately before my arrival. Wasn't for about an hour that the smell became noticeable. After the 3 hour drive home, I had to change my t-shirt it was so minging.

    No other fault codes from HVAC. Fan is working, although did seem weak until I removed the pollen filter. You can hear the duct flaps moving around (and get a different minging smell) when switching to recirc and going from cold/hot on the climate unit.

    Don't really fancy risking removing gas myself as:
    A) Don't want to risk frostbite
    B) Wouldn't know how much to release
    C) Think of the poor polar bears/it's illegal
     
  5. niggle

    niggle Rollin' on 17s, baby!

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    Valet Pro sell an enzyme based deodoriser. Give all of the absorbent interior surfaces a spray with the deodoriser and then leave the car locked up for a day or so for the enzymes to work their magic.
     
  6. Scott_FR

    Scott_FR Active Member

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    Already paid a detailer to give the whole interior a good going over. The plastics were literally thick with tar. He cleaned all plastics and glass, wet vac'd the carpets and seats, then used an enzyme solution everywhere including the headliner. But no bueno.

    But it's given me a good clean starting position. Going to try Ozone shock treatment, which I'm confident will work, as they use that to get rid of burning smell in fire damaged houses, etc.

    No one heard of issues with the heaters before?
     
  7. Scott_FR

    Scott_FR Active Member

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    I'm going to have a go at flushing out the heater matrix. Can't see how a 3 year old heater matrix could possibly have got blocked, but struggling for any other ideas at this point in time.

    Coolant is orangey in colour and stinks as well (although from looking at a number of engine bay pics on here, the orangey colour doesn't seem uncommon - which is a concern, given G13 is bright pink!). So that will be getting drained and refilled.
     
  8. dw911

    dw911 Active Member

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    Are the pipes to the heater matrix both hot, I'd be looking to see if I could get at the heater matrix if that's hot your issue is something else, I'd do that before flushing the system.
    Start with the simple things or you could just expend a lot of time on money and still not get to the cause
     
  9. Scott_FR

    Scott_FR Active Member

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    Was hard to tell the other day, as everything in the engine bay was hot. Couldn't tell if the pipes were hot because they were filled with coolant at 90 degrees, or whether they were just hot due to radiation from within the engine bay.

    The car runs at a perfect temperature, so I have ruled out an issue with thermostat or water pump.
     
  10. dw911

    dw911 Active Member

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    Hitachi
    Yes it's probably better to measure on the joints as it goes through the firewall with a laser thermometer if you have one, return should obviously be fractionally lower than the flow in your case.
    You said your showing no heater fault codes, that tends to rule out an actuator or similar, now assuming you have hot water flowing through heater matrix, I'd be thinking that the flap that directed air from the blower through the heater matrix into the car is not working, maybe something has snapped or simply come detached, or something along those lines.

    Just to add, from what you said the car was very very heavy with nicotine, that could be enough to gum up sometime like a heater flap, it's pretty sticky stuff
     
    #10 dw911, Sep 6, 2016
    Last edited: Sep 6, 2016
  11. Scott_FR

    Scott_FR Active Member

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    Sadly my peasant's toolbox doesn't extend to a laser thermometer. :)

    Agree that the tar from smoke is very sticky, but I doubt sticky enough to overpower an actuator. And given there is dual climate controls, surely unlikely it would have stuck vents for both sides in place?

    Looks like there is very little room for manoeuvre under that dash.
     
  12. dw911

    dw911 Active Member

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    Thats fair enough, although you can get one from maplin or online from China for a fiver, not great but would do the job.

    The dual control would make no difference as it's only likely to be one main flap of the heater matrix ,then other flaps further down the line to mix for dual contols etc or something along those lines
    Don't think it's an actuator, that should show as a fault code, but you may have snapped something or something has come loose.
    The mating surface of these flaps normally have a foam gasket, I've seen then stick shut if contaminated and or left in the closed position for a long time so I'd say it's feasible
    Ever tried opening a double glazed window in say a pub or factory smoking room, that will give you the idea of how sticky fag tar can be :D

    Access is as you say not easy, but if you have heat to the matrix that would be the next place to look as if you have heat to the matrix the only other cause I can see is that blown air not being sent where it should or through the matrix by the flaps
     
    #12 dw911, Sep 6, 2016
    Last edited: Sep 6, 2016
  13. Scott_FR

    Scott_FR Active Member

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    Had a look behind the glovebox today when I had a spare few minutes. That heater matrix isn't going anywhere without a full dash strip., and no access to flap actuators either. Crossing my fingers it is just a blocked matrix (but on the other handx hoping it isn't!).

    Got a load of service items arriving for the weekend. Just hope wifey doesn't go into labour first!
     
  14. Solo

    Solo Active Member

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    I had this problem with my golf tdi. Turned out to be a broken heat exchanger. Dealer replaced it under warranty.
     
  15. Scott_FR

    Scott_FR Active Member

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    The heater matrix is the heat exchanger. It's effectively just a small radiator that lives in the air ducts.

    What age/mileage was your golf on when they did it? Would be amazed if one had managed to corrode sufficiently to get blocked up in 3 years, but that could be exactly what has happened.

    Unfortunately for me, i'm the 2nd owner, and it hadn't been serviced exclusively by Seat, so don't think I would have any chance of getting anything done under warranty.
     
  16. Solo

    Solo Active Member

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    Indeed. My golf was about 2 and a half years old when it broke. Middle of winter too which was no fun, especially as I had to wait a month for the dealer to fit me in. Mileage was about 55k at the time and the car had been serviced by main dealers at the required intervals (long life schedule). I did get a low coolant warning a week before it stopped working but I topped it up and it remained fine afterwards. It took the dealer a week to fix it as apparently it was a nightmare to get at it. They replaced the coolant bottle at the same time. Or, they had the car for 4 days doing nothing and did it in a few hours on day 5?!
     
  17. Scott_FR

    Scott_FR Active Member

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    That is shocking! Feels like it's possibly confirming my worst fears.

    What a fool I am for not checking the heater worked on a 25 degree day in August! :)
     
  18. Scott_FR

    Scott_FR Active Member

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    Update time...

    Managed to squeeze in a service on the car, all filters and fluids.

    First task was to drained this disgusting looking coolant;
    [​IMG]
    [​IMG]

    It stank to high heaven!

    This is the colour of the stuff that came out, alongside some BARS to flush the system out with, and the lovely new G13 which was due to replace it.
    [​IMG]

    Before adding the coolant flush, I thought i'd see if the matrix was blocked. I'd run some water through it and see if it came out the other side. Simple stuff. That is, until I realised it was going to be difficult to get to the matrix connectors on the bulkhead. Cue a Scrapheap Challenge style rummage around my very cluttered garage!

    Managed to find an old coolant hose from an old S4 which i'd dismantled. I then had to figure out how i'd attach it to the hose. Realised I had a drain unblocking attachment on the pressure hose. It was too small a diameter for the coolant hose.
    [​IMG]

    A quick bit of bodging with some electrical tape later...
    [​IMG]

    Got it connected to a matrix connector and tried to run the water through off tap pressure. It barely trickled out. So I gave it a little burst with the pressure washer switched on and...
    [​IMG]

    Lovely, so we had some flow, but not much. At least i'd be able to run the coolant flush through the system which would hopefully clean up any remaining blockages. I attached the hose to the other matrix connector and back flushed it. Switched between them a couple of times to ensure i'd got everything out which I could.

    Reattached the hoses, put the flush stuff through, refilled the system with water and brought the car up to temp. This stuff lets you leave it in for a couple of days, so I took the car out on the road, running it at high revs to keep the water pump pressure up higher to try to dislodge more crap. It seemed like I might be onto something...

    I finally had a bit of warmth through the heater vents, although it was pretty asthmatic in its delivery.

    Came home, dropped the fluid again, refilled with water, got it back up to temp again and finally dropped that fluid as well. Finally, put all the G13 in, then topped up with water. Success!

    The following day, went for a drive. Vent temperature seemed week. The following day... stone cold again!

    But, i'd run out of time to progress any further. Just as I was tidying up my tools, the wife popped her head out of the front door. She had just dropped some fluid of her own. She was in labour!
     
    #18 Scott_FR, Oct 3, 2016
    Last edited: Oct 3, 2016
    LouG likes this.
  19. Keyzer Soze

    Keyzer Soze Active Member

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    Congrats, but you're going to need a working heater if you're transporting a baby.

    Sent from my Nexus 10 using Tapatalk
     
  20. dw911

    dw911 Active Member

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    Congratulations :)

    Could it be heater matrix circulating pump has failed, or maybe is gummed up with all the muck you found in there?
    If that pumps not working, you won't get any heat, as the main engine water pump can't circulate water through the heater matrix on its own
     

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