All 9×1 platforms (981 and 991) have very poorly designed radiator fan shrouds in the forward section of each front wheelhouse. These open design shrouds/ducts allow debris, rocks and fresh asphalt to get thrown, or basically fed directly into the Air Conditioner (A/C) condenser/radiator fan motors, which most always completely destroys the cooling fans and most importantly the cooling fan electric motors. Without a properly operating A/C condenser fan(s) this can cause excessively elevated A/C system pressures which leads to elevated temperatures and then this undoubtedly leads to A/C compressor shut down.
It is possible to have a PDK equipped 9X1 with complaints about a symptom that particularly occurs when taking off from a stop. Test drive the vehicle, when the brake pedal is released, the RPM’s might fall and then stabilize again before the car takes off from a standstill. If you experience these symptoms, both the A/C condenser fans are probably seized, thus causing a disproportionate drag on the engine. This excessive drag is caused by the combination of excessively high A/C compressor head pressures which also creates increased load on the charging system at idle; the end result is that the Digital Motor Electronics (DME) Control Module cannot maintain the nominal 650 rpm while the clutches for the PDK are engaged. The A/C condenser fans/motors should both be replaced, the fault codes cleared and the adaptations properly performed, and this should clear up these running issues and symptoms.
The usual operators’ complaint is when the A/C outlet air temperature warms at idle speed, or you may simply retrieve fault codes P1460 and P1466 which are stored in the Controller during a Vehicle Analysis Log (VAL) creation, also known as a controller interrogation. At the end of the day, replacing the A/C condenser fan motors is not the proper fix; it is simply correcting the symptom. The obvious valid repair would be for the fender liners and shrouds to be re-designed. There is a Technical Service Bulletin (TSB) numbered WE21 relating to this issue, it only pertains to the 2014/2015 GT3’s, but unfortunately not for any of the other 9X1 platforms.
Living in snow country, and many of our cars are driven year-round (they’re all-wheel drive right?) we see a lot of radiators and condensers covered in muddy slush from winter use. I am surprised we have not run into this issue as of yet….. What would be really cool is if there was a removable screen, similar to a snow screen found in many Audi air filter intake ducts, that could be removed from the underside of the lower splash shields and cleaned/ replaced.