We just purchased a 2006 F350 King Ranch. When idling at a stop light, we notice that the air coming out of the vents warms considerably and that when we start driving again, after some time, the air cools again. This same thing happened on the 2005 F250 we traded in, but in only occurred in normal A/C mode, so we kept it in recirculate to combat the issue in the F250. The "new" F350 has the issue in normal or recirculate A/C mode. We have an appt to take the truck back to the place of purchase next week. However, I'm concerned that we are going to be told that this is a normal feature of the truck OR it's not going to be noticeable enough to get a service tech to take us seriously. To me, it's only noticeable (and very annoying) when it's really hot out.

Is this a problem with Ford vehicles? Any suggestions?

 

I had the same issue last summer on the 2005 I just traded in.

One would expect the condition you describe to be "normal" on a hot summer day when in fresh air mode, because as you sit still on a calm day with no winds, the temperature in the engine compartment heats up quickly and thus you're trying to cool hotter air.

However, if the same condition exists when you're in recirculation mode (max A/C), then you most likely have a vacuum leak. The vent door that switches from normal mode to recirculation mode is vacuum actuated. A vacuum leak will prevent the door from actuating to fully closed, and if the leak is really bad it won't close at all.

Once I found and fixed my vacuum leak, all was well again and my max A/C acted as it should.

Here's a good way to test for a vacuum leak. When you arrive home, turn your climate control to OFF. Sit there and idle for a good minute or so. Then turn the truck engine off and wait about an hour. When you return after the hour has elapsed, with the engine off and no key in the ignition, just turn the A/C control **** to max A/C. You should hear a hissing sound and your should hear the vent door closing. If you hear nothing, then it's a sure sign that you have lost vacuum to a leak.

The second possibility is that you're simply low on refrigerant. Naturally, your A/C compressor is less effective when it's turning slowly at idle RPMs than when it's spinning at higher cruise RPMs. Nonetheless, the system is designed to provide effective cooling even at idle speeds, but when the refrigerant level is low the difference will be much more noticable. A top-off with one of those bottles from the auto parts store could be of benefit. From my experience, a vehicle that's hit the 5-year mark is usually in need of refrigerant top-off.

 

Mine stays cold at idle. It should not get warm. Have A/C checked for full charge. I'm in the middle of the Sonoran Desert. I can explain HOT if you need me to. haha
06 F350 Lariat, Crew Cab, Dually

 

A common sign of AC clutch failure is disengagement at low or idle speeds. If you vehicle has no vacuum leaks and is full of R134 then I would be looking at the clutch slipping at idle speed. MY truck has done the exact same thing. A short term fix is to take the shim washer out from under the clutch.

 

Baja Daze... I have electronic controls (no *****) for the A/C. With no key on, it does nothing??

Phantom... thanks, but it's hot enuff here in FL. This girl needs her A/C!! :-)

Jimmy... that's EXACTLY what they said the problem was with our F250 and that it was not a part under warranty, so I just drove it with the A/C in recirc all the time (which was better for my allergies anyway).

Well, we'll take it in next week and see what they say. It doesn't have a factory warranty but the place we bought it from offers a 1 yr warranty, 50/50 (we pay half, they pay half). My hubby is pretty good at mechanics... is taking the shim washer out from under the clutch a difficult job?

 

One little bolt.

 

I had the exact same problem with my '06 F350. Worked great going down the road, but warm at idle. I suspected fan problems, but it turned out to simply be an overcharged system. My mechanic bled off some refrigerant to get it back down to normal and now it will freeze you out at idle.

 

It is a common issue for the air gap to exceed the limits, as stated, try checking the air gap of the compressor.

http://springerpop.net/F350/air_gap.html

 

Thanks for the replies! I take it in to the shop tomorrow morning. I'm going to print this page out and take it with me! :-) Of course, I'll let them come up with the solution on their own, but if they say it's fine, I'll be able to talk about the solutions all of you have mentioned.

Thanks again!