Roscoe5

Member
Hi, only had the p38 one week and trying to sort problem with internal fans not running. Had fans out cleaned checked they are all ok. I think I have narrowed it down to the distribution flaps. All other blend motors seem to be running fine. Temperature is good etc. Anyway the distribution flaps seem to work when you first power the system up but then as you go to feet only heat or feet and windscreen then back to forward heat the flaps down lift up again. They are not getting caught on the box from what I can see. It's like the motor is forgetting where it's settings are.
Is there anyway of resetting these without having the dash out?
Kind regards
 
Distribution motor has a lot more work to do that the blend motors. Distribution flaps tighten up making it stall. Only proper way of freeing them is to strip heater but that is a big job. Can be cycled with diag that would also point you in the right direction. But only real way of knowing is to remove the motor and see how free the blend flaps are. If they are tight free them off. Can sometimes be done by fitting a self tapper between the two heater halves to spread them a bit. But does not always work.
 
Wasn't there a 'Self-Tapper Screw' mod to free up the distro flap??
 
Wasn't there a 'Self-Tapper Screw' mod to free up the distro flap??

Self tapper screwed into to open a gap between two heater case halves. Tried it on mine didn't work, it was a tight quadrant on mine. If the quadrant is remove is MUST be correctly aligned with marks on front and aft gear wheels in both directions.
 
Is the book symbol showing on the HEVAC screen ?
Yes book is showing as soon as ignition on, wont run anything. If you disconnect white connector on hevac and plug back in with ignition on it all comes to life until the next time you cycle the ignition. Can hear all blend motors working while book symbol is up though.
 
Distribution motor has a lot more work to do that the blend motors. Distribution flaps tighten up making it stall. Only proper way of freeing them is to strip heater but that is a big job. Can be cycled with diag that would also point you in the right direction. But only real way of knowing is to remove the motor and see how free the blend flaps are. If they are tight free them off. Can sometimes be done by fitting a self tapper between the two heater halves to spread them a bit. But does not always work.

From what I can feel the flaps seem to be moving freely from looking inside with a borescope. It seems that the motor just keeps going even when the flaps are fully closed. You can hear it straining then it stops. After that the flaps won't raise again.
 
It sounds as though the control pots , or at least 1 has gone us these tell the motors where the flap is.
 
This is what I need then! Hopefully can have a play around with it on a diagnostic. Now just need to find somewhere that doesn't charge silly money just to plug it in
 
First thing you should purchase is a Nanocom. I resisted for a while but once purchased, wondered how I managed without.

Even helped me with some preventative maintenance, too.
 
I had the same 'stiff flaps' problem, tried the screw bodge but couldn't lever the 2 halves apart, so reverted to drilling 2mm hole in the bits of the airbox you can access by taking the centre vents out and removing the switch panel on the centre console. Then bent the thin tube of a can of silicone oil to 90 degrees and squirted it through the holes in all directions, while turning the grey toothed actuator thing at the RH side back and forth (as shown on the vid) - it gradually eased and got much looser. It's been fine now for a few months.

Good luck.
A
 
Easy way to prove whether it's Flaps or Motor, is to remove the motor first, and try moving the flaps by hand. You will feel straight away if they are sticking. Take out the instrument panel, and then you can undo the two screws holing the distribution motor. Then move the grey flap gear to see if it's sticking.

I eventually found mine was the flap-shaft, and not the actual flaps, so no "screw method" would have worked. The fix for this was to remove the dash, and then remove the heater box. Then I dismantled the box, and drilled the flap-shaft holes about 0.5mm bigger to allow free movement. Proper fix, and no problems since. While the dash is out its easy to either replace the heater o-rings, or do the "Audi Heater Core" swap.
 
Last edited:

Similar threads