Author Topic: Heat exchange / Dash heater  (Read 6348 times)

Offline Notch000

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Heat exchange / Dash heater
« on: December 16, 2020, 08:41:59 AM »
Hi,
I have no heat in my cabin. I've taken it to two garages not this year that have fluffier around the issue and failed to fix anything. The last guys claim the matrix look fine as there is hot water in both inn & out lines and most likely a control valves that stuck and advise me to source this valve.
 
I have look though all the guide but I cannot but cannot find any valve ?? only a heater flap motor, or left right diverter thing ?? my car is an early Axx engine non aircon. Can anyone advise ?

At this stage I going to try flush out the matrix myself over the holidays and possible look at replacement the matrix altogether, Im pretty sure it blocked as the ifst garage replaced thermostats & cleared blocked pipe work due to previous owner using water in coolant. they never looked at heat exchanger.

Offline fakie1977

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Re: Heat exchange / Dash heater
« Reply #1 on: December 16, 2020, 09:09:01 AM »
Does your engine get up to temperature? When I had to change my thermostat because it wouldn’t get up to 90C, I couldn’t get heat into the cabin. As soon as I had it changed it fixed it.


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Offline Notch000

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Re: Heat exchange / Dash heater
« Reply #2 on: December 16, 2020, 09:11:55 AM »
get to temperature, a little slowly tho

Offline titchy

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Re: Heat exchange / Dash heater
« Reply #3 on: December 16, 2020, 09:46:31 AM »
matrix could blocked water in and out but not circulating through

Offline Notch000

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Re: Heat exchange / Dash heater
« Reply #4 on: December 16, 2020, 10:28:19 AM »
is there an ''electronic heater control valve'' with in the system somewhere ? this is waht the last mechanisw was recommending changing

Offline Notch000

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Re: Heat exchange / Dash heater
« Reply #5 on: December 16, 2020, 10:31:03 AM »
i found this tread that might help ?v talk about an air flap that directs air thought the matrix

http://www.vwgolf.net.au/showthread.php?15301-Mk5-Heater-Temperature-control

Offline Notch000

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Re: Heat exchange / Dash heater
« Reply #6 on: January 11, 2021, 01:21:43 PM »
Update:
I pulled the glove box out, and panels off and confirmed there is v hot water in heater core both pipes. Also the exteral recirculation flap motor is working ok, next i need to check the heater hot cold mixer valves. I replaced the pollen filter(really clogged up) and cleared out the scuttle drain under the dash cowl. Still no improvements. The Heat knob (manual) turns a leaver that disappears back inside the dash away into the background somewhere, so i need to pull a few more panels off and see if this is working or not.

Does anyone have a guide or an exploded diagram of this areas ? i am not sure what is easily removable or not !

Offline Notch000

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Re: Heat exchange / Dash heater
« Reply #7 on: January 18, 2021, 08:07:22 AM »
i flushed out the core at the weekend. It wasn't particularly blocked but 15years of S****T & sludge got knocked out all the same. I flushed back and over a few times with a garden hose, duck tape and some 3/4'' ID hosing through the matrix. I also soaked matrix a couple of time's with a kettle of boiling before back flushing. Ive had a decent improvement in the heat output. Its a handy DIY job
I also went digging under dash and confirmed the mixer vents and recirculation motor is working fine, I've definitely a thermostat issue now with the heat. I think il DIY the two line thermostats (DSg) before passing over to mechanic to replace the main one. (look a balls of a job). Temp doesn't seem to get over 80* while moving. Gets to 90 very slowly when idling