Hissing sound from AC

[jfe1]

Has anyone had this issue before? When I turn the AC on there is a hissing sound coming from the left rear somewhere. Sound like it is coming from either the roof lining or the B-pillar behind the driver's seat. Anny suggestions as to the issue before I start ripping the upholstery apart.

 

[JUST4FUN]

Um post the year please trim line

 

[IMINYOURCHAIR]

left rear could be the ac evaporator expansion valve if it's the '97 to '02. 03+ have the rear hvac on the right side.

basically, you have a little orifice that separates the high/low side of the ac system and the freon and oil will hiss past that where it enters the evap coil to take in heat.

 

[jfe1]

Um post the year please trim line

Sorry for that, it is an '05 XLT.

 

[Static54]

Sorry for that, it is an '05 XLT.

My 2013 does that as well. I don't know if it's ac only but definitely the same issue.

 

[IMINYOURCHAIR]

I don't know if the newer models have it, but the 1st gens have a panel that covers where the blower motor is for the rear ac/heat. on mine you can see the expansion valve there. check there for the noise while the truck is idling with ac on