6th Gen ('00-'05): AC problems
#1
07-25-2020, 05:25 PM
AC problems
Change compressor, dryer, and suction lines.. added freon to system and I'm only getting room temperature air... my problem b4 I changed everything.. was that my air would blow cold for a lil bit.. than stop blowing cold... so that made me changed all those parts... now I'm not getting no cold air... what am I doing wrong??.. keep in mind I'm just a dude with tools and watching a lot of YouTube videos... I got help with changing out the compressor... all my parts came from rock Auto..
#2
07-27-2020, 11:17 PM
Did you change orfice tube? And what are you low and high side pressures with outside air temp?
#3
07-30-2020, 06:20 PM
I have a kind of related question. I just ordered an A/C compressor, clutch, and two different sized orifice tubes for my 2001 MOC SS. I hope I ordered the right ones! They both said they would fit??? I will not be putting them in, the mechanic will be doing that, but his quote for the parts was pretty high. I hope I ordered the right one... how can I tell?
#4
08-04-2020, 10:48 AM
finally found the orfic tube.. replace it.. did a vac on it.. blew cool for 20min.. went out.. I gave up and sent it to the shop
#5
08-04-2020, 10:49 AM
I have a kind of related question. I just ordered an A/C compressor, clutch, and two different sized orifice tubes for my 2001 MOC SS. I hope I ordered the right ones! They both said they would fit??? I will not be putting them in, the mechanic will be doing that, but his quote for the parts was pretty high. I hope I ordered the right one... how can I tell?
#6
08-05-2020, 12:57 AM
As a mechanic one of my specialized skills was ac diagnosis and repair. So I’ll ask some background questions.
Even from the factory there were usually 2 different orifice tubes a car could be built with. Best practice is to remove the old one and match the colour and type.
1. How long was the system not in working order?
2. When these parts are removed is there still pressure in the lines when you disconnect things? Or is it properly recovered first?
3. Which type of refrigerant is being used to fill after?
4. Are you using a vacuum machine to pull a vac on the system for a minimum of 45mins before charging with refrigerant?
5. When installing the parts how much oil was added to the system? Too much can cause just as much problem as too little.
6. What type of oil was used?
7. When the ac is turned on are the high speed cooling fans running? Do you hear the clutch cycling? If cycling, time the intervals and tell me the outside air temperature of that day.
8. How much refrigerant in pounds was it charged with?
Lets start with that and see what’s said then move forward.
The reason for the long vac step is vacuum boils off water at ambient temperatures, water and refrigerant create hydrochloric acid when combined. Hydrochloric acid and aluminium are a very bad combination, and ac systems are 90% aluminum.
Even from the factory there were usually 2 different orifice tubes a car could be built with. Best practice is to remove the old one and match the colour and type.
1. How long was the system not in working order?
2. When these parts are removed is there still pressure in the lines when you disconnect things? Or is it properly recovered first?
3. Which type of refrigerant is being used to fill after?
4. Are you using a vacuum machine to pull a vac on the system for a minimum of 45mins before charging with refrigerant?
5. When installing the parts how much oil was added to the system? Too much can cause just as much problem as too little.
6. What type of oil was used?
7. When the ac is turned on are the high speed cooling fans running? Do you hear the clutch cycling? If cycling, time the intervals and tell me the outside air temperature of that day.
8. How much refrigerant in pounds was it charged with?
Lets start with that and see what’s said then move forward.
The reason for the long vac step is vacuum boils off water at ambient temperatures, water and refrigerant create hydrochloric acid when combined. Hydrochloric acid and aluminium are a very bad combination, and ac systems are 90% aluminum.
Last edited by Justin Knight; 08-05-2020 at 01:01 AM.
#7
08-05-2020, 11:35 AM
As a mechanic one of my specialized skills was ac diagnosis and repair. So I’ll ask some background questions.
Even from the factory there were usually 2 different orifice tubes a car could be built with. Best practice is to remove the old one and match the colour and type.
1. How long was the system not in working order?
2. When these parts are removed is there still pressure in the lines when you disconnect things? Or is it properly recovered first?
3. Which type of refrigerant is being used to fill after?
4. Are you using a vacuum machine to pull a vac on the system for a minimum of 45mins before charging with refrigerant?
5. When installing the parts how much oil was added to the system? Too much can cause just as much problem as too little.
6. What type of oil was used?
7. When the ac is turned on are the high speed cooling fans running? Do you hear the clutch cycling? If cycling, time the intervals and tell me the outside air temperature of that day.
8. How much refrigerant in pounds was it charged with?
Lets start with that and see what’s said then move forward.
The reason for the long vac step is vacuum boils off water at ambient temperatures, water and refrigerant create hydrochloric acid when combined. Hydrochloric acid and aluminium are a very bad combination, and ac systems are 90% aluminum.
Even from the factory there were usually 2 different orifice tubes a car could be built with. Best practice is to remove the old one and match the colour and type.
1. How long was the system not in working order?
2. When these parts are removed is there still pressure in the lines when you disconnect things? Or is it properly recovered first?
3. Which type of refrigerant is being used to fill after?
4. Are you using a vacuum machine to pull a vac on the system for a minimum of 45mins before charging with refrigerant?
5. When installing the parts how much oil was added to the system? Too much can cause just as much problem as too little.
6. What type of oil was used?
7. When the ac is turned on are the high speed cooling fans running? Do you hear the clutch cycling? If cycling, time the intervals and tell me the outside air temperature of that day.
8. How much refrigerant in pounds was it charged with?
Lets start with that and see what’s said then move forward.
The reason for the long vac step is vacuum boils off water at ambient temperatures, water and refrigerant create hydrochloric acid when combined. Hydrochloric acid and aluminium are a very bad combination, and ac systems are 90% aluminum.
#8
08-06-2020, 08:55 AM
Never add oil to the dryer, the compressor coming with oil in it is good.
What it sounds like to me are these possible issues, and I would start here because one or more of them will likely solve the problem.
1. The system is over saturated with oil and it’s fouling the orifice tube and pressure switches.
2. The compressor clutch relay is worn out.
3. The system is being over charged with Freon, or you’re using the wrong type and it’s freezing the evaporator into a block of ice.
4. Back to oil saturation, too much is just as bad as too little. Recover the freon, take things apart, drain out as much oil as you can from everything except the compressor. DO NOT add more oil, pull vacuum with pump for 1h continually, give full freon charge with R134a and start system. If the compressor is not chattering it has enough oil.
Going from what you’re saying it sounds like oil saturation to me. So start on that second because the relay is easy to swap with another, like the horn relay. They are the same relay and unless you’re an angry driver the horn relay hasn’t had the same amount of usage.
Please tell me what type of oil you used, the refrigerant type, and if you added any sealers or leak stops at anytime in the cars life.
Thats the one variable I forgot to mention the first time. If it’s had a sealer or leak stop added to it at some point in its life, you’re in a world of trouble to get it to work properly again with big $$$ spent.
Let me know what you find out.
What it sounds like to me are these possible issues, and I would start here because one or more of them will likely solve the problem.
1. The system is over saturated with oil and it’s fouling the orifice tube and pressure switches.
2. The compressor clutch relay is worn out.
3. The system is being over charged with Freon, or you’re using the wrong type and it’s freezing the evaporator into a block of ice.
4. Back to oil saturation, too much is just as bad as too little. Recover the freon, take things apart, drain out as much oil as you can from everything except the compressor. DO NOT add more oil, pull vacuum with pump for 1h continually, give full freon charge with R134a and start system. If the compressor is not chattering it has enough oil.
Going from what you’re saying it sounds like oil saturation to me. So start on that second because the relay is easy to swap with another, like the horn relay. They are the same relay and unless you’re an angry driver the horn relay hasn’t had the same amount of usage.
Please tell me what type of oil you used, the refrigerant type, and if you added any sealers or leak stops at anytime in the cars life.
Thats the one variable I forgot to mention the first time. If it’s had a sealer or leak stop added to it at some point in its life, you’re in a world of trouble to get it to work properly again with big $$$ spent.
Let me know what you find out.
#9
08-07-2020, 11:05 AM
As for myself, I know they checked mine for leaks. It ran cold for a few minutes after they recharged it, (on the way home), but next time I used it, no more cold air. Still blew out lots of air, but not cold. They said it needed a new compressor... wouldn't it need a new condenser also? I don't know enough to ask intelligent questions.
#10
08-09-2020, 08:53 PM
As for myself, I know they checked mine for leaks. It ran cold for a few minutes after they recharged it, (on the way home), but next time I used it, no more cold air. Still blew out lots of air, but not cold. They said it needed a new compressor... wouldn't it need a new condenser also? I don't know enough to ask intelligent questions.
Most shops aren’t aware of the issues they’re causing when they add too much oil to the system. If there was no leak and it worked on the way home, it probably had too much Ac oil added (assuming the blend actuator is still working).
The one other problem is that the compressors used in GM’s are 3 and 5 piston variable displacement designs. There is an internal shaft and depending on the displacement required a sliding bushing allows for that. If the brand new compressors sit on a shelf too long at the part store they lock up and sometimes need a good rubber mallet whacking once they get hot to free it up. Doesn’t work every time but I’d say 60% success. The other 40% gets another comp under warranty.