A/C compressor cycling 2 sec on 5 sec off

[Cstoliker]

A/C does not get cold. The compressor does turn on, but only for about 2 sec before shutting off for about 5 sec, then back on for 2.
I have a pressure gauge and the low side climbs to 45 when compressor is off (Equalizing) and rapidly drops to 25 after the compressor turns on.

Its a 95 XLT 4.0L

 

[Joe Dirt]

The cycling usually means a low level of 134 in the system.

 

[KRWebster]

Does anyone know what the high and low pressure values should be for a properly charged and functioning system (1997 XLT, 4.0 SOHC) with the compressor on and off?

 

[BrooklynBay]

Add a little more freon until the compressor stops cycling.

 

[Cstoliker]

I tryed that first. I bought a 20 Oz can but it did not seam to take much of it. No real change. Could a clogged Orifice tube cause it?

 

[BrooklynBay]

You need to connect a manifold gauge set to compare the high & low side pressures in order to determine if the orifice tube is clogged. You will have to evacuate the system before you replace the orifice tube. They are color coded, so make sure that you replace the orifice tube with the correct color.

 

[Cstoliker]

No matter if i need just an tube or a compressor i will need to Evac the system anyway. So i can visualy inspect the tube. What is the location & color or the one I want to look at?

 

[Joe Dirt]

The orifice tube is not visible from the outside. The system needs to be evacuated it is in an enlarged section of line going from the condenser to the accumulator

 

[Cstoliker]

Crap.. Do I need some sort of special tool to get the quick connect fitting off?

 

[BrooklynBay]

Yes, you need a special snap lock coupling tool.

 

[Cstoliker]

All right, I removed the old tube. It was cruddy but I do not think clogged. I replaced it. Question now is do I spend $30 on freon to find out it was not the problem or just replace the compressor for $180?

The compressor does not show any of the classic signs of failure like Noise, seized or a leek. But as the only moving part, is the likely candidate. Suggestions?

 

[fedyfedz]

Go with the freon get a can of arctic freeze from pepboys and it comes with a gauge. I did this to my 2002 v8 2 days ago and a/c blast's cold air now before that it was just hot air. Once the system cycles on push the button until it cycles off then stop then complete steps multiple times. Also with the ac on max blasting the whole time. It took me about 20 minutes to empty a 22 oz can into my system. The can i got was designed by NASA and has 21oz of freon and 1 oz of sealant that seals any leaks and the can is proven to make a/c 50% colder 50% faster when my x sits for a day in the hot sun as soon as i turn it on it takes 16 secs to get ice cold i timed it hahahah

 

[Cstoliker]

The system is completely empty since I changed the orifice tube. Should I add oil and how much?

 

[fedyfedz]

The artic freeze comes with oil mixed in I dont think you will have to add any oil. Mine had a drop in it and i just put the can it works great

 

[Cstoliker]

I recharged system. It took just over 2 12oz cans. A/C works great now.
I do have some concerns though. The system was opened and exposed to atmospere, i did not evac, just closed and charged. I used the artic freeze 134 wich says it has additives to remove moisture and reduce acid. Each 12oz can says it contains 1oz oil and 11oz refrigerant. So i effectively 2 oz oil. I am assuming the system retained most of it oil as the liquid oil settles in different parts of the system and would not come out with the gas when dischaged.

So from a line disassembled pressure less system I added about 24oz of 134, & 2oz oil. It is working. It was 98 today and it was more then adequate. But do you think it will be ok or could I be doing alot of damage. The truck has 190k on it so I do not expect it to last 10 years.

 

[96eb96]

Its not ok, but it will probably (fingers crossed) give you a few years. You are compressing air and moisture now, and I believe that affects oil flow as well.

If you do it right the next time be sure to replace the dryer tank.

Then again, many techs balk at adding anything into a system but pure R134a (some will not touch a system with additives), but lots of people do it and it seems to work.

 

[Glacier991]

<sigh> If you open the system it needs to be evacuated before you recharge. I won't repeat the littany of problems that NOT doing that can produce, but moisture from the air will create acid in the system, and acid will...well... let's just say that a couple years of service will be a good estimate... could go longer. But when it quits it will be fubar.

 

[scapino]

Is this related to my A/C problem?

First, this thread is 5 years old so I'm not sure if anyone is still following?

I've got an '05 Exp Sport Trac that I bought new (original owner). :yelexp: I don't normally use A/C, instead preferring to have the windows down. Buy my G/F likes A/C so I guess I like A/C too...

Anyway, I turned on the A/C for the first time this year and get very little cool air. I just assumed that I needed a recharge so I bought the recharge kit from AutoZone. When I plug in the pressure gauge to the Low Pressure Port, turn on A/C to max, and wait for pressure to stabilize - only it does not stabilize.

I hear the compressor kick on and pressure rises to 55psi. Then the compressor kicks off and pressure drops to about 15psi. Then the cycle repeats; compressor on for 10 seconds till it hits 55psi, then off 3-4 seconds till pressure drops to 15psi. And the blowing air is only mildly cooler than ambient.

Any thoughts on what the problem is??