I have a 2006 screw with the 5.4 and I get a hissing type noise from the A/C. It cycles every 7 seconds and sounds like it's coming from the far passenger vent area. It sounds like it's recharging itself or something. I've taken it into the dealer and the first time they said it was the vacuum driven system then the second time they said it was the freon recharging itself. Is every 7 seconds a little to often? It seems to get louder the longer I drive. Needless to say after a four hour trip to the beach hearing this hissing every 7 seconds drives me crazy. It will hiss then stop for seven seconds then hiss again. Anyone??? Thanks.

 

I don't know about you but outside of the truck with the air on i can hear a clicking noise maybe about every 30 seconds. Do you have that too?

 

I've got the loud clicking noise on my '06 5.4L Screw and the hissing sound on my '06 5.4L Expy. Dealer tells me both are fine.

 

I never got out to listen but I will now to see if the clicking is there. Every 7 seconds seems a little much to me.

 

I get the clicking noise as well in my 05 SCrew FX4 when the A/C is on, but it is not cycling every 7 seconds. that seems a bit excessive.

 

This may not be the case, but I had the same problem with hissing a few months back. Every time I turned on the fan, the hissing got louder. I looked and looked and almost tore apart my dash. Then, I noticed the sound was coming from a bottled coke I had in the cup holder in front of the vent. Yes, I felt dumb. The noise was from a partially opened and partially shaken coke bottle. This probably is not your problem, but I thought it was worth mentioning.

 

I was just curious if you ever got this problem resolved, as my 07 Lariat screw does the same thing, but for 5 seconds, with 5 second intervals.

 

The clicking noise you hear on the outside of your truck is nothing to worry about

 

My 07 Lariat also makes the intermittent "hissing" noise. I figure it is compressed refrigerant going through an expansion valve, but I do not hear it on my buddies 2004 XLT F-150. Maybe it has something to do with the automatic A/C control system.

 

I hear it on all my newer ford vehicles so I guess that is just the way that it is, which is fine with me.

 

Do they all have auto climate? Just curious, because my 07 MKX doesn't make the noise, just my F-150.
Thanks

 

The 03 excursion and 05 f250 have auto climate but the 06 f150 does not and they all seem to make the some noises with the air on.

 

If you have the EATC then yes it is normal, the computer will control the ac and do a bunch of different thing to control the ac, one thing is to put in on 60 degrees and press the vent button with the max ac/recirculate button, this eliminates the AUTO function, which is the computer controlled function

 

Mine does the same hiss thing. I brought it to the dealership and they couldn't duplicate the noise.

 

My 2006 FX4 does it too, i have the auto climate control thingy too, i only notice when the radio is off though, and that is not very often so it doesn't really bother me too much!