Noticed over the last few weeks that while im pottering around town at 30/40mph or sat in traffic my aircon is ice cold but as soon as i reach motorway speeds it turns boiling hot and i mean HOT.

Ive resorted to just turning it off on the motorway but earlier on while on a 50mph road i nailed it to overtake a tractor, my speed was in excess of 60mph and the aircon started to go hot while under heavy acceleration. Soon as i was back at cruising speed and in a 30zone it was ice cold again.

Anyone had this before?

Wondering whether one of your vent flaps is opening letting hot air into the cabin. Have you tried it on the recirc setting?

Edited 17 June, 201412 yr by pauldazzle

Yeah i dont think the recirc flap works tbh. I thought it could be that but surely it would still allow for the cold air coming in from the aircon. The hot air coming into the cabin is hotter than the highest heat setting on the car

Could the recirc flap be opening at speed letting hot air in? :think:  Have you got good flow from the headertank return pipe?

Yeah got good flow from that lol. Maybe the aircon needs regassing, it might not be able to cope at higher speeds with the heat generated from the powerhouse lol

Just in case one of the flap valves has failed and is moving in the faster air stream, run the climatronic self test.

Here is my earlier "how to do it" post and following thread:

 

http://www.briskoda.net/forums/topic/209451-climatronic-self-diagnose-mode/

 

Just guessing but if you are low on gas and then run at higher engine/compressor revs, maybe something happens on the air con side?

Ive done a test on it before, think it was 4f7 that came up. The air con system is 11years and 132000 miles old, so theres every chance its low

That code is the recirc flap and shouldnt account for your issue

Ive done a test on it before, think it was 4f7 that came up. The air con system is 11years and 132000 miles old, so theres every chance its low

 

Hex code 4f7 equates to Decimal 01271

 

Ross Tech says this code is for a faulty motor on the temperature control flap:-

 

"01271 - Positioning Motor for Temperature Flap (V68): Faulty Possible Causes

• Wiring/Connectors from/to Positioning Motor for Temperature Flap (V68) faulty
• Positioning Motor for Temperature Flap (V68) blocked
• Positioning Motor for Temperature Flap (V68) faulty

Possible Solutions

• Check Positioning Motor for Temperature Flap (V68)
  • See Measuring Value Blocks (MVB)
  • Perform Output Test
  • Perform Basic Setting
• Check/Repair Wiring and Connectors"

 

Definitely a strong contender for investigation. Speculating, it could be the flap has disconnected from the motor shaft and (dare I say it) just flapping about in the air flow, and so changing the temperature if the air flow increases with vehicle speed.

 

EDIT: Just found this video of the temperature control flap and comments on youtube which may or may not be related. The comments say it works as shown when tested and "I did fix the problem. The servo was at fault after all. I replaced the servo after which temperature adjustment has worked perfectly. What is odd though is how the faulty servo seemed to work perfectly when I was testing it and even for one full week after I had disassembled it"

 

Edited 17 June, 201412 yr by pikpilot

Just to chuck something else into the pot - I am pretty sure that at large throttle openings, the aircon is disabled on purpose....a normal feature of these (and many other) cars....