Recently in my 2011 Volvo C70 with 53,000 miles the air conditioning occasionally started blowing warm on passenger side of car and then occasionally switched to driver side. It was never more than approximately 30 seconds and would then go back to cold. This doesn't happen all the time when I drive the car. Then, when this issue would happen the passenger side would not only blow warm but started blowing "extremely" HOT. It would stay this excessive for about 30 seconds and then blow cold again. If you were sitting in the passenger side it would be difficult to even stay seated.

I first took it to my local shop and they did the following on three different visits over 4 weeks. 1) Checked and added a small amount of a/c freon. 2) Replaced valve core. 3) Replaced a/c hose. All three attempts didn't work. The car was then dropped off at the local Volvo dealership/service center. After the tech diagnosed the a/c system it was determined everything was in excellent condition. All levels were satisfactory and the system has no issues. Tech was confident that there was no need to have the a/c compressor replaced.

They CONCLUDED that the C70 can have this issue when you drive the car and go from stop and/are going slow to then quickly accelerate to a higher speed. They said there is no fix for this problem. Is this diagnoses correct? I am 53 years old and have owned many cars (even a previous Volvo) and have never heard of this. Unfortunately I know very little about car specifics and thus don't know much about car repairs. Any suggestions would be appreciated. Thanks.