AC Temp 56 degree after shop diagnosed and recharged it

[Infinity00]

47 Edit: 56 degrees at the vent with 84 degrees outside running max cold setting at night. Does this seem warm? I paid a shop to evacuate, diagnose and recharge. They said it holds 1.8 (kg?) and I had only 0.6 in it. They were surprised at how cold it was blowing with 0.6.

The only thing leaking was schrader valves so they replaced those and topped off the Freon adding 1.2. They said my dirty air cabin filter was making it so it wasn’t as cold as it should be, and it replacing would solve the problem. Still doesn’t blow any colder than it did before they worked on it. I have the rear cool button, does that mean I have rear AC and maybe I need more Freon than 1.8?

 

[Racerman27410]

did they evacuate the system , pull a vacuume and weigh the charge back in? there could be a stuck expansion valve. is the electric aux fan on the condensor running? ...... have you checked the cabin air filter make sure it isnt really dirty? there are several things that can cause a system to not get cold but you really need a pro to figure it out.

 

[Infinity00]

Yeah they did all that and the cabin filter. They said it need 1.2 refilled and it’d been leaking thru the schrader valves which they replaced. The pros worked on it! I’m thinking I need to work on it next, I never let the pros work on my vehicles bcs ultimately I have always had to redo their work regardless...I thought this was something they could do

I’ll check the aux fan, good suggestion

 

[danthemanx07]

47 degrees? Warm? Sounds like it is working well to me. Is it supposed to get colder than that?

 

[Infinity00]

I sure am hoping it does. Doesn’t feel cold when it’s hot outside. The AC thermometer has a green region between 38-42. Does anyone know if it needs more Freon than 1.8 kg? With a rear ac system?

 

[Infinity00]

So I found this chart for amount of refrigerant. I hope it’s wrong, or else the shop I took it to grossly overfilled my GX, and it would explain why they “only” found 0.6 kg of refrigerant in it and were surprised that it was cooling as well as it was. The attached chart shows a quantity of 22.4-24 ounces for a GX with only front air. This equates to 0.635-.68 kg. For one with rear AC, the quantity is bumped up to 28.1-28.9 ounces, which equates to 0.797-.82 kg. The shop added 1.2 kg to my 0.6 kg they pulled out.

Can anyone confirm these numbers? I’ll call Lexus tomorrow to check and look for a sticker under my hood.

 

[langsen]

Double check that the flapper behind the cabin air filter is actually moving when you push the recirculate button. Mine was stuck in the fresh air position, and here in Phoenix that meant that I never got cold air out of the vents.

 

[Infinity00]

Ah , thank you, I’ll check that.
I called the shop and they said they put 1.2 lbs of Freon into it (not 1.2 kg). Regardless, when I mentioned it held ~1.8 lbs, he then said they put the .6 back in that they originally took out. So maybe they did maybe they didn’t. I asked where that was documented and he couldn’t tell me. I’m taking it back in tomorrow for another “diagnostics” to see what they blame for the “leak” they now suspect I must have, even tho they said there were no leaks the first time. As you can see I’m jaded. I never take my vehicles in to shops just bcs of this type of thing, but I thought they could handle the AC where I’m not totally comfortable since I don’t have the gear.

Anyway, thanks for the responses. My aux fans are coming on.

 

[Infinity00]

Got my car back, they think my condenser is clogged. They say the outlet normally get hot and mine were cool after running it for a long time. So the compressor turns off when it shouldn’t because it’s not seeing refrigerant. Quoted $671. I asked what happens if that doesn’t fix it, and he replied they’d do more diagnostics. Compressor is good they are pretty sure. It doesn’t make any noise and seems to be doing what it’s supposed to.

 

[langsen]

They are sure they got the charge weighed in correctly? They vacuumed it down and charged it with the rear AC turned on, right?

Try spraying the condensor with water from a hose while the AC is on and see if the vent temps drop. Seems like if it's clogged then there will be no difference.

I would post over at autoacforum and see if those guys have any ideas. Also, Autozone loans out pretty much all the AC tools, if you decide to learn how to do it on your own.

 

[Infinity00]

I can’t seem to get that forum. I’ll check with autozone, I’m assuming I’ll need something to capture the R134a into. I have everything else but that and a way to get the contained refrigerant back in. I’ll try the hose spraying here in a few minutes and post the results. For anyone else needing the part number for a dual AC condenser, it’s 88461-60091 $294 at Norwalk. $325 at Lexus parts now.

 

[Infinity00]

Is my condenser behind the aux fan, shown on the left of the picture? What’s the other little radiator below the horns on the right side of the picture? Is that the tranny cooler? My hoses coming off the little one below the horns are leaking and I want to identify so I can buy hoses.

 

[captainva]

That would be the trans cooler

 

[Infinity00]

Soooo...I sprayed both just to see what would happen and now my aux fan isn’t coming on anymore. The temp will drop from around 48 to 46 if I gun the engine and with the water on the condenser (without aux fan running). I’m hoping after it dries out the fan will work again!

Update: the aux fan came back on after everything baked in the sun for a while.

With no water on condenser and revving the engine with recirculated air on and max auto cold the vent temp is around 48 and climbing ever so slightly.

With water on the condenser and everything else is the same as above the vent temp drops by 2 degrees.

So what does that mean?

 

[langsen]

When you spray the condenser with water, it can transfer a lot more heat than it does with air flowing over it, so it basically shows you how well the condenser could possibly work. That said, this "test" is not definitive, there is still a chance the condenser is a problem. You would need a set of gauges to troubleshoot this properly. But, since there was such a small change in temperature, I would expect that the condenser is ok, and would start troubleshooting other components.

Did you get a chance to check the recirculator door? You're 100% sure they charged it correctly? The FSM has instructions on how to roughly estimate if the charge is good by timing how long it takes to see bubbles in the sightglass after the system is shut down. Is the compressor cycling on and off? How is your fan clutch?

If they end up taking it all apart, you might consider updating the condenser and expansion valve with the parts listed in TSB AC-003-06.

 

[langsen]

I just went outside and measured the temperature at the vent on mine, but it is 110 here so this may not be useful. Parked, idling, with the doors open and AC on max = 55°F. Driving, AC on max = 50°. Driving, AC on lowest speed = 34°; on 2nd lowest speed = 40°. I realized I never use the max blower speed and usually use the lowest two.

 

[Infinity00]

Well I just called another shop more local to me (and recommended by another reputable shop who people love but who only work on toyota and Honda’s). Anyway, the service guy I was talking to said he’s been working on these for 45 years and it doesn’t sound like the condenser to him unless it was damaged somehow. I’m kinda trusting this guy especially since he said they stand behind their diagnoses and the other shop I’ve been dealing with basically said “it’d rule it out”, when I asked how they handle it if that didn’t fix it. Sooo...yeah I’ll start digging into this more.

I do have gauges. I’m confused, you have it on the lowest setting and it is colder? Should I be testing on the lowest setting? The differential temp for you is amazingly large 110-34 deg. Is that real? I thought max differential temps was closer to 40 degrees. I need to find an FSM

 

[Infinity00]

Re: the recirculating door, I can hear it doing something and the speed changes but I haven’t had a chance to pull the glove box and directly look at it. Compressor is cycling often. Fan clutch seems good. I’ll check the fan clutch better tho and make double sure it’s good.

 

[ship it]

Did you find out what was wrong?

 

[Infinity00]

Nope. Starting to investigate again though. I’ll post up if I find anything. New shop that I took it too last week didn’t find anything wrong. Recharged it and ran dye thru it but said nothing was leaking and the system looked good. It’s only getting to 57 degrees now but it’s been really hot, mid 90s easy but even when it was in the 80s it runs around 57 deg also.

What are your symptoms? Oh, I did find a tsb on the ac for 2003 and 2004, looks like an expensive repair if going that route.

TSB for AC improvement for 2003-2006 GX470:

https://testing-public.carmd.com/Tsb/Download/23919/L-AC003-061