1998 S70 Hot AC with icing AC lines and hissing sound

aong · Post by **aong** » 30 Aug 2014, 17:33

I have been driving my 98 Volvo S70 since it was new, and I love the car. Recently, the AC started to blow hot air after 10-15 mins of driving. I added Freon and it was around 35 psi. Still, it did not correct the situation. I opened the hood and I notice there was ice on the AC lines. Please see attached. After I turned off the AC and the car, I heard a hissing sound from the dash or the hood. Any idea on what the problem may be? I a newbie to AC. Thanks for all the advises.

Post by **Ozark Lee** » 30 Aug 2014, 18:30

Is the cabin blower running and is the cabin air filter clean? A lack of air flow over the evaporator in the cabin of the car can cause it to freeze up.

The hissing after you turn it off is the refrigerant going back to the accumulator, it is normal. Some of them even whistle when you shut them off.

...Lee

aong · Post by **aong** » 01 Sep 2014, 13:12

Thanks for the help. Cabin air filter was the cause. It was too dirty.

Happy and safe driving everyone!!!