Model S60 AC Intermittent and Making Noise

[rjcampeau]

Last summer during a really hot day (40+C), my AC just stopped working, which was quite scary because we had to get our 5 week old baby home asap before the car got too hot. According to the teslafi log, it got up to 36C inside. Later that day I hopped in my car and it worked just fine and we didn't have issues until a few weeks ago.

Now it seems to flake out on moderately warm days, but will sometimes blow cold just fine. At my last service appointment they said the coolant was full and they couldn't find any issues. When the AC is working it makes a squeaking noise (video below), which service must have missed.

Before I go back, I feel like I need to have a more solid idea whats wrong - any ideas?

 

[DerbyDave]

There is a chiller that cools the high voltage battery and a valve that controls how much cooling goes to passengers and the battery. I feel sure it will always prioritize the battery over passenger comfort if necessary. Maybe the chiller or the control valve is not working. The noise might be a bad compressor, pump or fan motor. If the fan isn't working right, you will definitely get hot. Does the noise vary with the fan setting, or is it constant?

 

[rjcampeau]

There is a chiller that cools the high voltage battery and a valve that controls how much cooling goes to passengers and the battery. I feel sure it will always prioritize the battery over passenger comfort if necessary. Maybe the chiller or the control valve is not working. The noise might be a bad compressor, pump or fan motor. If the fan isn't working right, you will definitely get hot. Does the noise vary with the fan setting, or is it constant?

It makes that noise when transitions from blowing warm when it should be blowing cold, to blowing cold like it should. Then it usually goes away or happens every now and then when blowing cold. Blower fan speed doesn't seem to make a difference.

I think I can rule out shunting AC to the battery as a cause, it's supposed to warn you when it does that and it shouldn't be doing that when ambient temp is like 18C!

 

[DerbyDave]

The battery is also cooled more when driving very aggressively, in hot weather, a battery issue, and when supercharging in summer when all the fans come on in your car. If there is something wrong in the sensors or control of this process, your interior AC could suffer.

 

[rjcampeau]

The issue was:

Correction: TXV Valve Evaporator (Remove & Replace)
Correction: Sensor - Pressure and Temperature - Low Pressure (Remove and Replace)

Back on the road for $1200 CAD