Ok, so i have aan annoying problem with my A4.. Occasionaly the heating stops working, if i go from LO (17 degrees) to say 24 it gets ever so slightly warmer, but not even luke warm... Unless i go up to HI (30 degrees) then it blasts out heat. Even if i go from HI to 29 it almost goes ice cold again. Whats wrong? It seems to do this more often when outside/ambient temp is warm like today when it was around 18c while driving... Havent checked any faultcodes and as it is a 2001 B5 it has the newer klima controll and i dont know if it is possible to diagnose through that. Any tips are appreciated.
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Heating problems B5 A4
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Heating problems B5 A4
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there is a known heating problem by audi 80 b4 typ and audi a4 that the little heating radiator inside the ventilationbox is getting clogged,no circulation at all
You can try flushing it with a garden hose
or try a cooling water flushing agentaudi coupe quattro b2 2.2 20vt project (573hp-626nm)
TWINCHARGED power,zero lag
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Forgot to mention i flushed it last year... Might be time to reflush it though. But if it would be clogged, then i suppose i shouldnt have any heating when i put in on HI? If it's on HI i get good heating.
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External tempsensor? As in outside temp? Or am i being an idiot now?
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Outside temp sensors on B5s often go wrong cos they're mounted just behind the lower rad grill.Last edited by newsh; 22 April 2014, 00:09.
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Is the front facia (in my case wood look) just clipped on? Have heard about that fan/sensor before... When should the fan be activated? Or is it activated as soon as ignition is on?
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Originally posted by fish View PostIs the front facia (in my case wood look) just clipped on? Have heard about that fan/sensor before... When should the fan be activated? Or is it activated as soon as ignition is on?
John
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Hi
Just went trough something similar on my B4 climate.
I reckon 90% it's a partially blocked heater matrix, why partially?
On mine the cold/not hot air issue was more from the lower ducts and less on the upper ones.
This depends on where the ducts are connected on the main central door on the air box.
If you have a noticeable (hands should be sufficient) difference of temperature from the three grids/vents on the dash
I.E. central (colder) grids and left (warmer) and right (warmer then the left) then the lower part ot your heater matrix it's blocked.
The temperature flap on the airbox deviates the air blow against or faraway from the heater matrix.
Then if you put on HI all teh airblow will go trough the heater matrix, when you start to calibrate a different temperature all starts to be affected by the clogged matrix and where it's blocked.
I hope I've been clear enough....
YOu can see the airbox and the central main duct and the temp flap on the airbox on this thread:
http://www.s2forum.com/forum/showthr...886#post774886
here my symptoms and the solution:
http://www.s2forum.com/forum/showthr...t=47071&page=2
Note that I changed:
The two internal temp sensors (believe B5 has only one in the dash with the little fan)
The two external sensors the one in the front behind the bumper and the one below the cabin filter (pity to get at it!)
But no avail.... It was the heater matrix original part fitted in 2009....
Hope this helps
Stefano
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Also the foam can fall off the flaps so they don't work properly.
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Originally posted by quattro-nick View Postthere is a known heating problem by audi 80 b4 typ and audi a4 that the little heating radiator inside the ventilationbox is getting clogged,no circulation at all
You can try flushing it with a garden hose
or try a cooling water flushing agent
Originally posted by johne View PostYour internal temperature sensor - the one behind the grill just above the climate control unit - is blocked by dust or the fan behind it that draws the cabin air over it has failed.
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Originally posted by fish View Post... Unless i go up to HI (30 degrees) then it blasts out heat.
John
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Ripping the center console apart today, i can feel the center axel for the little fan spinning with my finger, i will see if it is fluffed up with dust. Will also check the flapmotors. I dont think it is clogged as i i flushed it with kaustic soda last summer, (its for cleaning drains = disolves most gunk) also, if it was clogged i doubt i would get burning hot heat when on HI. I will let you know what happens. Thanks once again.
Kris
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