A/C Troubleshooting Saga Continues.....
07-04-2005, 11:16 PM
#1
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Thread Starter
A/C Troubleshooting Saga Continues.....
My original problem is that the A/C does not blow as cold as it used to.. Just barely cool.. and the low pressure line is not FREEZING cold when running..
Ok, I cleaned the condensor and Radiator today.. But that seemed to only make a nominal difference.. However I noticed some more things that may be significant!
On I put the gauge on the Low pressure side and watched it while the air was on high..
It would start out at about 35psi and then start climbing to about 50psi then the Fans would kickk on and the pressure would start dropping back to 35..
BUT.. I noticed that the Compressor NEVER shut off.. It stayed on the ENTIRE time.. I have never seen this on other cars... The compressor is supposed to shut off periodically? right? If it is not then what could be wrong?
Ok, I cleaned the condensor and Radiator today.. But that seemed to only make a nominal difference.. However I noticed some more things that may be significant!
On I put the gauge on the Low pressure side and watched it while the air was on high..
It would start out at about 35psi and then start climbing to about 50psi then the Fans would kickk on and the pressure would start dropping back to 35..
BUT.. I noticed that the Compressor NEVER shut off.. It stayed on the ENTIRE time.. I have never seen this on other cars... The compressor is supposed to shut off periodically? right? If it is not then what could be wrong?
07-05-2005, 02:21 AM
#2
Burning Brakes
You might have air in the system. It is also possible your orifice tube is plugged. What was the history just before the system started to stop working properly? Was it opened up. Do the fans cycle on and off?
07-05-2005, 09:03 AM
#3
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Thread Starter
Originally Posted by white90conv
You might have air in the system. It is also possible your orifice tube is plugged. What was the history just before the system started to stop working properly? Was it opened up. Do the fans cycle on and off?
Never opened or leaked... Just slowly stopped getting real cold...It a 2000 with 30,000 miles..
07-05-2005, 09:27 AM
#4
Drifting
[QUOTE=On I put the gauge on the Low pressure side and watched it while the air was on high..
It would start out at about 35psi and then start climbing to about 50psi then the Fans would kickk on and the pressure would start dropping back to 35..
BUT.. I noticed that the Compressor NEVER shut off.. It stayed on the ENTIRE time.. I have never seen this on other cars... The compressor is supposed to shut off periodically? right? If it is not then what could be wrong?[/QUOTE]
You should only use pressure #'s when the fans are running. If the fans are off the condensor is not effective and your pressures will be off. 35 is an ok reading. On a very high temp day it might not cycle. You don't have your high side pressure. This will tell if the orifice tube is plugged. If your high side is in the "225 - 265" or so range your refrigerant system should be working properly. It is also possible not to "ice" up given a hot enough day with low enough humidity. What is the temp of the air comming out of the coldest duct. Use a stick thermometer and put it into the vent. Use high blower with both doors open. Also did you drive and test the a/c after cleaning the condensor. 99 Nassau Blue
It would start out at about 35psi and then start climbing to about 50psi then the Fans would kickk on and the pressure would start dropping back to 35..
BUT.. I noticed that the Compressor NEVER shut off.. It stayed on the ENTIRE time.. I have never seen this on other cars... The compressor is supposed to shut off periodically? right? If it is not then what could be wrong?[/QUOTE]
You should only use pressure #'s when the fans are running. If the fans are off the condensor is not effective and your pressures will be off. 35 is an ok reading. On a very high temp day it might not cycle. You don't have your high side pressure. This will tell if the orifice tube is plugged. If your high side is in the "225 - 265" or so range your refrigerant system should be working properly. It is also possible not to "ice" up given a hot enough day with low enough humidity. What is the temp of the air comming out of the coldest duct. Use a stick thermometer and put it into the vent. Use high blower with both doors open. Also did you drive and test the a/c after cleaning the condensor. 99 Nassau Blue
07-05-2005, 11:03 AM
#5
Race Director
Thread Starter
[QUOTE=jimcork1]
You should only use pressure #'s when the fans are running. If the fans are off the condensor is not effective and your pressures will be off. 35 is an ok reading. On a very high temp day it might not cycle. You don't have your high side pressure. This will tell if the orifice tube is plugged. If your high side is in the "225 - 265" or so range your refrigerant system should be working properly. It is also possible not to "ice" up given a hot enough day with low enough humidity. What is the temp of the air comming out of the coldest duct. Use a stick thermometer and put it into the vent. Use high blower with both doors open. Also did you drive and test the a/c after cleaning the condensor. 99 Nassau Blue
Never drove it and tested it. I checked it in the garage idling. VERY HIGH Humidity and about 85 in the garage..
Also why did the compressor never shut off?
The Air coming out of the vent I need to check with a thermometer.. But just going by feel.... I' guess 68 to 72... I thinks it;'s supposed to be closer to 55 right?
Originally Posted by On I put the gauge on the Low pressure side and watched it while the air was on high..
It would start out at about 35psi and then start climbing to about 50psi then the Fans would kickk on and the pressure would start dropping back to 35..
BUT.. I noticed that the Compressor NEVER shut off.. It stayed on the ENTIRE time.. I have never seen this on other cars... The compressor is supposed to shut off periodically? right? If it is not then what could be wrong?[/QUOTE
It would start out at about 35psi and then start climbing to about 50psi then the Fans would kickk on and the pressure would start dropping back to 35..
BUT.. I noticed that the Compressor NEVER shut off.. It stayed on the ENTIRE time.. I have never seen this on other cars... The compressor is supposed to shut off periodically? right? If it is not then what could be wrong?[/QUOTE
You should only use pressure #'s when the fans are running. If the fans are off the condensor is not effective and your pressures will be off. 35 is an ok reading. On a very high temp day it might not cycle. You don't have your high side pressure. This will tell if the orifice tube is plugged. If your high side is in the "225 - 265" or so range your refrigerant system should be working properly. It is also possible not to "ice" up given a hot enough day with low enough humidity. What is the temp of the air comming out of the coldest duct. Use a stick thermometer and put it into the vent. Use high blower with both doors open. Also did you drive and test the a/c after cleaning the condensor. 99 Nassau Blue
Also why did the compressor never shut off?
The Air coming out of the vent I need to check with a thermometer.. But just going by feel.... I' guess 68 to 72... I thinks it;'s supposed to be closer to 55 right?
07-05-2005, 04:18 PM
#6
Burning Brakes
If the AC is on high and the temps are hot enough the compressor will run continually. Something you said did catch my attention: when the AC is on HIGH and RECIRC the fans should be running the whole time, not cycling off and on. Is this the case?
07-05-2005, 04:41 PM
#7
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St. Jude Donor '08
Your getting some very good advice here. Jumcork1 and T56gen3 are RIGHT on the money! I also believe tht when the AC is ON the fans should run all the time!!!
I was always under the belief that the difference between the outside and air out of the center vents on high speed was in the neghibor hood of 20 deg difference.
I just went out and cranked up the 02 Z06 and fired up the AC. The fans (BOTH) came on FAST and then kicked down to (BOTH) on low. As the coolant temp got up to 190 deg (fans are programmed to come on there) they both went to high. The out side temp was 83 deg @ 78 percent relative humidity. The Inside center duct (fan on high and system on recirculate drivers door open) dropped right down to 55 deg. The AC compressor NEVER cycled off. There are come AC systems (not in corvetts) that use a cycling clutch method of regulating evaporator temp and discharge pressure. The C5 is NOT a cycling clutch system. If your clutch ever cycles, it normaly indicates that your are very low on freon.
Bill C
I was always under the belief that the difference between the outside and air out of the center vents on high speed was in the neghibor hood of 20 deg difference.
I just went out and cranked up the 02 Z06 and fired up the AC. The fans (BOTH) came on FAST and then kicked down to (BOTH) on low. As the coolant temp got up to 190 deg (fans are programmed to come on there) they both went to high. The out side temp was 83 deg @ 78 percent relative humidity. The Inside center duct (fan on high and system on recirculate drivers door open) dropped right down to 55 deg. The AC compressor NEVER cycled off. There are come AC systems (not in corvetts) that use a cycling clutch method of regulating evaporator temp and discharge pressure. The C5 is NOT a cycling clutch system. If your clutch ever cycles, it normaly indicates that your are very low on freon.
Bill C
07-05-2005, 05:53 PM
#8
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Thread Starter
Originally Posted by Bill Curlee
Your getting some very good advice here. Jumcork1 and T56gen3 are RIGHT on the money! I also believe tht when the AC is ON the fans should run all the time!!!
I was always under the belief that the difference between the outside and air out of the center vents on high speed was in the neghibor hood of 20 deg difference.
I just went out and cranked up the 02 Z06 and fired up the AC. The fans (BOTH) came on FAST and then kicked down to (BOTH) on low. As the coolant temp got up to 190 deg (fans are programmed to come on there) they both went to high. The out side temp was 83 deg @ 78 percent relative humidity. The Inside center duct (fan on high and system on recirculate drivers door open) dropped right down to 55 deg. The AC compressor NEVER cycled off. There are come AC systems (not in corvetts) that use a cycling clutch method of regulating evaporator temp and discharge pressure. The C5 is NOT a cycling clutch system. If your clutch ever cycles, it normaly indicates that your are very low on freon.
Bill C
I was always under the belief that the difference between the outside and air out of the center vents on high speed was in the neghibor hood of 20 deg difference.
I just went out and cranked up the 02 Z06 and fired up the AC. The fans (BOTH) came on FAST and then kicked down to (BOTH) on low. As the coolant temp got up to 190 deg (fans are programmed to come on there) they both went to high. The out side temp was 83 deg @ 78 percent relative humidity. The Inside center duct (fan on high and system on recirculate drivers door open) dropped right down to 55 deg. The AC compressor NEVER cycled off. There are come AC systems (not in corvetts) that use a cycling clutch method of regulating evaporator temp and discharge pressure. The C5 is NOT a cycling clutch system. If your clutch ever cycles, it normaly indicates that your are very low on freon.
Bill C
So my A/C only comes on initially with low fan... Then it jumped to high fan and continued to cycle high and low fan to regulate the pressure...
So the one this I never really checked.. was those DAMN DAMPER DOORS! If I find out that all this is because one was stuck in mixing mode I am gonna be PIAZZZED!
How can I visually check the doors before I just bring it to an A/C shop?
But the doors still don't explain why the low pressure hose is not FREEZING! FU$%K I hate this...
07-05-2005, 10:06 PM
#9
Race Director
Thread Starter
Originally Posted by Bill Curlee
Your getting some very good advice here. Jumcork1 and T56gen3 are RIGHT on the money! I also believe tht when the AC is ON the fans should run all the time!!!
I was always under the belief that the difference between the outside and air out of the center vents on high speed was in the neghibor hood of 20 deg difference.
I just went out and cranked up the 02 Z06 and fired up the AC. The fans (BOTH) came on FAST and then kicked down to (BOTH) on low. As the coolant temp got up to 190 deg (fans are programmed to come on there) they both went to high. The out side temp was 83 deg @ 78 percent relative humidity. The Inside center duct (fan on high and system on recirculate drivers door open) dropped right down to 55 deg. The AC compressor NEVER cycled off. There are come AC systems (not in corvetts) that use a cycling clutch method of regulating evaporator temp and discharge pressure. The C5 is NOT a cycling clutch system. If your clutch ever cycles, it normaly indicates that your are very low on freon.
Bill C
I was always under the belief that the difference between the outside and air out of the center vents on high speed was in the neghibor hood of 20 deg difference.
I just went out and cranked up the 02 Z06 and fired up the AC. The fans (BOTH) came on FAST and then kicked down to (BOTH) on low. As the coolant temp got up to 190 deg (fans are programmed to come on there) they both went to high. The out side temp was 83 deg @ 78 percent relative humidity. The Inside center duct (fan on high and system on recirculate drivers door open) dropped right down to 55 deg. The AC compressor NEVER cycled off. There are come AC systems (not in corvetts) that use a cycling clutch method of regulating evaporator temp and discharge pressure. The C5 is NOT a cycling clutch system. If your clutch ever cycles, it normaly indicates that your are very low on freon.
Bill C
In fact now that I think about it.. The radiator actually had more crap on it than the Condensor... Which I realize was blocking the heat transfer from the condensor all the way through the radiator..
So what I have now..is.. It feels much colder on the Passenger side...(Almost the 55 degree mark) I am only going by feel in comparison to my daily driver but.. more like maybe 60ish.... But the Driver side STILL feels 10degrees warmer
Even on recirc...
07-05-2005, 11:22 PM
#10
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Location: Anthony TX
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St. Jude Donor '08
My 98 and 02 Z have (KNOCK ON WOOD) have never had issues with the AC or HVAC system other than a clogged air box drain. I will need to dig DEEP into the service manual to give you any info on this issue.
I just found out that I need to make a trip to Portsmouth NH tomorrow for business and I wont be back until late Friday. Please be patient.
If you check and clear all codes and then disconnect yoyr battery, it might help. Sometimes that works to sync the doors in the air box.
BC
I just found out that I need to make a trip to Portsmouth NH tomorrow for business and I wont be back until late Friday. Please be patient.
If you check and clear all codes and then disconnect yoyr battery, it might help. Sometimes that works to sync the doors in the air box.
BC
07-05-2005, 11:25 PM
#11
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Thread Starter
Originally Posted by Bill Curlee
My 98 and 02 Z have (KNOCK ON WOOD) have never had issues with the AC or HVAC system other than a clogged air box drain. I will need to dig DEEP into the service manual to give you any info on this issue.
I just found out that I need to make a trip to Portsmouth NH tomorrow for business and I wont be back until late Friday. Please be patient.
If you check and clear all codes and then disconnect yoyr battery, it might help. Sometimes that works to sync the doors in the air box.
BC
I just found out that I need to make a trip to Portsmouth NH tomorrow for business and I wont be back until late Friday. Please be patient.
If you check and clear all codes and then disconnect yoyr battery, it might help. Sometimes that works to sync the doors in the air box.
BC
07-06-2005, 09:02 AM
#12
Drifting
Originally Posted by chuckster
So what I have now..is.. It feels much colder on the Passenger side...(Almost the 55 degree mark) I am only going by feel in comparison to my daily driver but.. more like maybe 60ish.... But the Driver side STILL feels 10degrees warmer Even on recirc...
Even on recirc...
99 Nassau Blue
07-06-2005, 10:50 AM
#13
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Thread Starter
Originally Posted by jimcork1
If you are getting 55 or so while driving in Florida,, your refrigerant system is working. Now to check your damper system. Perhaps others can help here,, fortunately my dampers still work. But if you have dual zone a/c you might try turning the temp to full cold and make sure the dampers are open for the air flow temp sensor to measure the air. My wife likes to close them totally off therefore the air doesn't pass through the duct and she still wonders why she can't warm it up.
99 Nassau Blue
99 Nassau Blue
Yep I have Dual Zone... and on full cold.. yet the Driver side is still warmer... So if anyone can help me get at the damper doors to take a look see.. I'd appreciate it..
