AC not blowing very cold
 

2017 Q7.

Noticed the AC really isn't blowing cold.

VAG shows the compressor is kicking on - but the temps from the vent are MUCH higher than my Q5 (1st pic vs 2nd pic). The refrigerant pressure is also much lower. Maybe a sign of low refrigerant?


https://cimg2.ibsrv.net/gimg/www.aud...d4a1389d95.jpg
Q7
https://cimg3.ibsrv.net/gimg/www.aud...2ad31aa083.jpg
Q5

Just noticed the same last week and the dealer said the freon level was low, so they recharged the system and pressure tested (no leaks) and now it's blowing nice and cold again.

something is definitely wrong here.

i don't understand why a 5 year old car needs a refrigerant top off unless it is leaking... did they dye the system and check for leaks?

They said they tested and found no leaks. FWIW, I have 130k miles and it’s ~100+ degrees here from June-September, so the system definitely gets a workout. Even though it’s technically a closed system, evaporation and small leaks over all that time can and do happen. In fact, it happened on my 2012 Q7 after a few years as well.

ok good to hear. makes sense. when I had issues on my 2017 they used a dye and I came back a week or two later and they found something leaking and replaced some seals and I was more or less good to go. that car did not cool as well as my 2018 does now, that thing blows ICE COLD and I will be happy as long as it stays that way.

Anyone know what the pressure should be? My Q5 is very cold at 16.8...

I will probably find an indy to re-charge the system - vs paying the dealer - I'm guessing it's a complete rip $$ to do it there. But I'll call them first and see.

VCDS screen probably showed the refrigerant pressure on the high side. 11.8 bar or 171 psi on the liquid line is definitely low for R134a. For ambient temperature between 85-95 F, the refrigerant pressure on the high side (liquid line) should be in the range of 220-270 psi. It is best to trace the leak and fix it first, but if the leak is small over a long period of time, you can get by by just recharging or adding refrigerant on the low side (suction line) to no more than 50 psi, Below are links to the charging port location and procedure: