A/C rarely putting out cold air

[pet575]

2004 4.6L v8; 204k miles

I'm having issues with the coldness of the A/C. It is blowing mostly warm to hot air at idle. It will become cold if you're driving at about 1,500-2,000 RPM but then will get warm again over 2,500 RPM.

The interior fan is blowing just fine. I checked the refrigerant level and it was at 55 PSI. I'm lost as to what is causing this. At idle and when not quite up to temp, the coolant line that runs across the top of the radiator/fan shroud assembly will rattle and vibrate. The sound has no effect on the temperature of the air though. I have a video of it that I'm trying to figure out how to post.

Anyone have any ideas on where to start? My first guess is compressor fan clutch but is only a guess. Thinking of surrendering early on this one and just taking it to the shop first thing in the morning to have them diagnose it.

 

[pet575]

For some reason the A/C worked a little better today so I haven't surrendered yet. I've done some poking around on the interweb tubes today and determined that I need to look at whether hosing off the condenser while running at idle will cause the air to get cold and that I also need to check the gap on the A/C compressor clutch to make sure it is not worn to the point of engaging poorly.

 

[pet575]

Here's a link to the video. Hopefully it can be viewed by all:

Video of vibrating coolant line

 

[pet575]

Nobody has anything on this?

 

[pet575]

Small update. I cleaned off my condenser and checked to make sure I didn't have the compressor clutch issue that some Fords in this year range are known to have. Minimal improvement (if any at all). System is most definitely full of freon.

I'm now starting to wonder if I don't have some type of vacuum/blend door type of thing going on here. I also now have a tapping/thumping noise from the rear fan area and it seems that the noise only takes place at idle speeds. Also, when I turn on the rear fan everything gets warmer. And when things get warmer it feels like the warm outdoor air with humidity-not just raw hot air or air that is slightly warmer.

I've thought about the possibility of a bad fan clutch. However, cold air performance is still great with higher RPMS and not necessarily only because I am traveling at speed. And it will still get VERY cold driving on the highway. Oddly, though, sometimes the coldest air I get is when I'm coasting to a stop after letting off of the gas. Sometimes even at idle after making that stop I get decent cold air.

There is really no rhyme or reason to whether I'm going to get cold air if I'm in stop and go traffic or idling. I still can't figure out a pattern to it. But I will undoubtedly get cold air on the highway.

I really don't want to get ripped off at Midas or the stealership on this one. Please help!

 

[pet575]

Still no resolution to this problem.

Question:

Would a worn A/C compressor clutch cause what I described above? Asking because I have a random chirping sound coming from under the hood that I have determined to be related to the compressor. Not sure if it is the bearing or the clutch going bad, but it does NOT occur when the A/C is not turned on. I've tried to monitor it closely but the chirping is so completely random I've not been able to see whether the compressor clutch is engaging when it happens. It may only chirp 1-2 times during an entire drive, and it seems to only take place at idle speeds.