Just bought a used 05 Grand Caravan. Whenever the AC is on you sometimes get a strange hissing noise. The noise always comes from the passanger side but somtimes it comes from the rear vent near the tailgate or up front under the glove box. The dealer I bought it from is trying to tell me it is normal and nothing he can do, but this noise can be heard even when the radio is on. Has anyone come accross this problem or know what is causing it? Thanks!
s38638i
04-04-2009, 09:41 PM
the freon in the ac system is low, it still my cool but will stop cooling soon, probably your rear ac lines are leaking.
Rick99
04-05-2009, 07:51 AM
There is a level of hissing that is normal when an A/C system is working right. The places you described are where the A/C evaporator cores are (two on your van)-- the refrigerant may make a hissing sound as it sprays into the evaporators. It shouldn't been too loud though. You'll just have to use your judgment on that. If you just bought it from them, they should be willing to check it out for you-- use their machine to recover the charge to see how much is in there-- if less than a full charge they should check for leaks, repair and recharge for you.
blakej59
04-20-2009, 06:14 AM
my 2001 has jsut started hissing loudly from the heater box when the AC is on. When you get to highway speeds, it stops. AC works good but gets weak and starts the hissing when you stop at a light. Sounds like a vacuum leak inside the heater box. Is there a servo inside that might be leaking? How do I access this box to see what's inside?
