Ac not cold at stops.

Last week I was driving with ice cold ac coming off the highway, we came to a stop and the air was warm. Any time I was driving the air was ice cold, come to a stop it was warm.

I changed out the fan clutch and it’s still doing it. Check Freon level at my friends shop and it was good. Swapped in new fuses and relay with no change.

I’m not sure what else it could be and trying to get this figured out.

 

Check that condenser, radiator, and between them is clean. Mine is like that, moving nice and cold, stopped cool. I suspect the valves in compressor are getting worn. How many miles do you have?

 

What are the air temps where you are at? Once the air temp gets to a certain high the AC has reached its limit to cool the interior. Also could be debris in the evap coil. But it could be just too hot out. An A/C shop should diagnose it better.

 

^This.

 

There's not enough airflow from the clutch driven fan to allow the AC to operate at the proper temperature it needs to in order to cool down the interior at idle. The fan simply doesn't spin fast enough based on the idle RPM these trucks run, which is why the moment you get moving it gets super cold again.

This issue gets discussed every summer and there's not much you can do about it outside of going an electric fan setup which would be the true fix or installing a pusher fan which 50/50 it actually gives you any noticeable results.

 

Isn't there a tsb for this and people have had this fixed by dealership?

 

Temps outside were 75-85.

has around 220k on it.

this is the first time it has done this since I’ve owned the truck.

 

Give the condenser and radiator a good cleaning

 

Really need to see what your pressures are doing idling vs driving, poor A/C performance at idle only is most often caused by:

Low charge
Condenser or radiator that is clogged with dirt or debris
Weak compressor
Failing expansion valve
Faulty fan clutch

Sounds like you have already addressed some of these, if I were diagnosing it I would put gauges on it, drive it, and see what the pressures do driving vs idling and proceed based on what I saw there.

 

75 to 85* is white a wide spread. Anything above the mid 80's and these trucks will be taxed. Which is BS in itself considering how "good" these trucks are supposed to be as a whole.

 

With engine idling, spray the condenser with a hose. If the cooling gets better you're looking a heat exchange issue at condenser. Might be dirty or corroded. Or look into one of those pusher fans

If that doesn't help, double check the refrigerant charge level.

Also keep in mind that its not just the speed of the belt driven fan that goes down when rpms are low but also the speed of the compressor. It simply doesn't move the same volume of refrigerant at idle so efficiency drops.

 

Amazing how many things can be fixed with a cleaning, and if necessary for the component, a lubing.
Agree with others, clean the condenser, radiator and area between.

 

I put the gauges on this morning, driving around 3000 rpm at 82 degrees low side was 19 and high was 175.

I talked to my friend and he said at that rpm and it should be around 120-140 on the high side like his tacoma. I’m thinking it couldn’t hurt to clean the condenser and radiator to help with the air flow.

we checked the ac compressor shims(in tolerance), and clutch was working.

so I will have a cleaning project this weekend and will keep y’all updated.

 

Underserviced/low refrigerant will also cause higher discharge temperatures and poor performance.

 

I don't think any of the Asian automakers ever did A/C as well as US manufacturers, especially GM. The A/C in my old Sonoma would literally freeze you out of the cab no matter how hot it was. Never had that issue with ANY Japanese truck of any type.

The other issue, cabs keep getting bigger and bigger and the A/C system hard bits stay the same. Sorry, can't put a 2 ton condenser in a house that needs a 4 ton unit and expect it to cool well and a vehicle is no different. Even paint color makes a huge difference as a dark color needs more cooling then a light color like silver or white.

 

Mine has done this since I got it. If sitting stopped for any length of time, I shift to N and run the RPM's up to 1,000 or so. I have to say my 2000 Chev silverado would freeze you out even on 100deg plus days, at idle. Toyota built the AC system just barely big enough to do the job.

 

They actually make a condenser coil cleaner for cleaning residential AC units that you can get at HD or Lowes. Comes in a spray can. I have used that with good results. Spray it on and try not to get it on the paint. I highly recommend removing the grill (it's two bolts and two plastic pins) so you can get better access to the area. Let it sit for a bit and then take a spray attachment on the hose and blast the hell out of it. You should be able to see through it when you're done. If there's stuff inside that keeps light from shining through air won't get through either.

 

UPDATE***
Cleaned the condenser over the weekend. The low side was reading 21 and the high side dropped to 129 after the cleaning at 80 degrees outside. Ac is ice cold, at stops it’s cold now.

I’m thinking the radiator may be my issue now. Idk if it’s slushy or coke but when cleaning the condenser out I had a lot of sticky blue dirt coming out in chunks. I got as much of it out as I can but some spots wouldn’t let light through. If I’m going to take it apart I would replace it with a koyo or something better.

 

Git one like they have across the Border...Méjico Tacos

 

From what I have read, pressure readings at 85f on average should read 220-250psi on the high side and 45-55 psi on low side. I'm not sure about the blue dirt. Could be a small refrigerant leak (oily) causing a chemical reaction with the aluminum condenser while collecting road grime and bugs. Speaking of, I use a coil cleaning foam on the condenser, radiator and trans cooler once a year. Remove the grill, spray it on , let it sit a little while and then gently wash it off and repeat the process. You do not want to bend the fins on the condenser or the radiator with a hard stream of water. The first time I did this the AC temperature dropped 5 degrees. I haven't cleaned it yet this year, but did a temp check over the weekend and my AC was blowing 43 degrees (center DS vent) while cruising through the neighborhood. I also added a pusher fan (just to the left of the trans cooler) to help when in traffic, or in West Texas or AZ where it's Africa hot!