A/C is not cold when idle

Good morning.

If the unit works when off idle going down the road, it sounds like the compressor is working.

As far as at idle, is the cooling fan working pulling air through the radiator?

Are the fins of the radiator and the AC condenser free of all dirt and debris? Common problem for this issue.

Do you have gauges to test the high and low side pressures at idle?

Roy

I checked for the debris and dirt and it is free and the condenser fan is working when the A/C is on.
The mechanic guy only checked the low pressure and he said the level is good. Is it important to check the high one as well? And if it is on what level it should be? I do not have the gauge but if if can get so I can check.
But he said your compressor qualification is not good. So I am not if it is true or not. He said the compressor need to be replaced, but I do not think this issue is due to compressor.

Notes:
Sometime when the weather is not that hot it is cooler than hotter weather.

You cannot tell Freon level from pressure.

Yes, you must check the high side as well. Would love to know these pressures while it is idling.

You need a new shop that knows about AC. The shop you were at does not know how to check the AC system.

Roy

Oh okay, then how do I check the Freon level then?
Definitely I am going to look for another shop.

If you have a site glass on the dryer, you can tell if it is clear with the AC on.

Beyond that, you need to recover the Freon and measure it against what is supposed to be in the system. There should be a tag under the hood as to the amount of Freon required in the system.


Roy

So you mean this issue is not related to compressor right? Just want to make sure because I do not want to get fraud by the mechanic.
What do you mean by site glass on the dryer?

Once I know the pressures I can answer about the compressor. At this point I doubt it is.

On the receiver dryer there may or may not be a sight glass to see the Freon. It will be on top of the dryer.

Roy

Okay, I took it to another mechanic and looks like the high pressure pipe has oil all over it especially from the bottom near to compressor. And he said the pipe need to be replaced as well as the compressor. I attached the picture aa shown below the leak part marked with arrow.

The line looks like it is leaking but why did he tell you the compressor?

It could very well be low in Freon from the leak.

Roy

I told him why I need to replace the compressor if the leaking is from pipe he said it was due the compressor fault. But I did not believe him I think he was trying to rip me off.
And he checked the low pressure from Freon he said it is okay.
So but most likely the leak is near to compressor end to high pressure pipe.
So I am not sure what to do.

Compressors do not cause a leak from a line. It is the line that has worn out.

Looking at low pressure is not an indication for Freon level.

Roy

So, I only need to repair the high pipe the end of the pipe that goes to compressor it has all cover like an oil.
I told him to check the high pressure as well using a gauge he said it does not need only low pressure needed for measuring Freon in a low pressure and he said its around 55-60 psi and there is no problem with Freon level.

He is wrong with not checking the high side. The low side is too high. It should only be 25-35 lbs. 50-55 lbs is too high. That indicates either a bad expansion valve or too much Freon.

Roy

But what about the hissing sound when AC is on? Is that due to that leak as well? I can hear it from inside and outside.

It could be but I am not there to hear it so anything I would say would be a guess.

Roy

I could wrong ng about the 50psi because it has other unite so it maybe another unite like a metric system I did not see it very clear I may go for another mechanic.

I just want to make sure that hissing sound is not from the compressor. The sound is exactly like this one in this video.
https://youtu.be/kbjmouPllSs

That is the sound of Freon flow. It may be low in Freon from the leak.

Roy

It is exactly what did you said. I took it to another mechanic he said Freon is less than a half because of the leak and yea he said the hissing sound is from compressor because there is not enough Freon to push that is why it makes that noise hissing sound, but there is nothing wrong about compressor but he is going to check anyway he is going to repair it after tomorrow then I am going to post the results.
it is going to cost me about $80.00.
Pipe = 25$
Freon=40$
Labor =8$
Thank you for your time. I learned a lot from you.

You are welcome.
Roy

Okay guys, long time no see. after i fixed those now the problem has come back again. went to mechanic he checked pipes no leak and Freon level is okay. he said this could be the compressor issue. just to remind the issue here the cooling air is cold when i drive but when idle or in a traffic area it became hot a little bit sometimes. it becomes so hot like the A/C is not on at all .
Just wanted to know if this issue is due to compressor or not before i replace it?
Thanks

Before you do that, try this:

Open the hood with the A/C on and the engine idling and spray the condenser with a garden hose and see if the air inside gets nice and cold.

Let me know what you find.

Roy

Okay. if i did that what will be the next? Probably going to do that tomorrow because it is night here.
Btw already checked the fan and it’s working fine and the condenser is clean from dirt.

One step at a time.

The next is pressures at idle. I need the high and low side pressures at idle.

Roy

After that happened i use push auto at 23 c. but now i have lowered to low and it is working fine. the air is cold. I sprayed the water to condenser now it is cold i has been idle for like 5 minutes.

Pressures?

Roy

Well, I cannot check the pressure by myself. i already checked before he said it was fine.

I need the pressure readings. that was then and this is now.

Roy

Well, i guess i have to take to a mechanic.

You can rent a set of gauges or buy a cheap set from Harbor Freight.

Roy

Okay, i will try to rent one and then going to post the results.

Sounds like a plan.

Roy

One note; when i start the car turn on A/C on i hear a hissing noise. It only happens occasionally.

That could be just the Freon.

Roy

So that is natural right? And lets say both low pressure and high pressure are in normal range that is going to be the compressor issue then right?

No, not at all. Let's cross that bridge when we come to it.

Roy

Oh, Okay. i am going check it after a couple days. thanks for the help.

You are welcome.

Roy

Okay, here the results looks like they both are in normal range.
But he said your compressor is getting weak and it’s an electric compressor not the clutch one and not sure what are those. He said since we are in summer and it is about 45c here so it kind of normal for those electric compressor.

Okay, no, they are not normal at all.


the low side is way too high. It should be 25-30 lbs. You are at 60.

You need an expansion valve and a dryer.

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

Roy