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'88 vert AC Hiss

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Old Jun 13, 2008 | 10:51 PM
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Default '88 vert AC Hiss

Hello..
I can hear a hiss from my engine compartment when my AC is on..it does not do it at idle..it seems to be ~ every 15 seconds and I can feel a drag in the drive train...any thoughts on what this is?...
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Old Jun 14, 2008 | 05:24 PM
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Originally Posted by Dan87GT
Hello..
I can hear a hiss from my engine compartment when my AC is on..it does not do it at idle..it seems to be ~ every 15 seconds and I can feel a drag in the drive train...any thoughts on what this is?...
...a hiss?....how is your a/c temp?....any oil around any of the fittings or the compressor?..i would think that it would be something else (like the clutch or belt on the compressor or even the air pump) because if you can hear the "hiss" that would seem to me to indicate a MASSIVE a/c leak and if that were true, i doubt that you would get even a days worth of "service" from it...
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Old Jun 15, 2008 | 10:35 AM
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The hissing sound you are referrring to along with the "15 second drag" could be simply needing refrigerant, as the "drag" could be caused by the compressor engaging/disengaging/engaging. Your a/c system might be low causing the a/c clutch to engage and disengage. Start the car and turn on the a/c on to full. Then look at the a/c compressor and check to see if the clutch is engaging. You will see one of three things; 1-the clutch is fully engaged (most likely not), 2-the clutch is going on and off (this most likely be what you are experiencing), 3-or the clutch is not engaging at all. My guess is that you need a shot of freon.
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Old Jun 15, 2008 | 10:50 AM
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Originally Posted by 89 Bob L
The hissing sound you are referrring to along with the "15 second drag" could be simply needing refrigerant, as the "drag" could be caused by the compressor engaging/disengaging/engaging. Your a/c system might be low causing the a/c clutch to engage and disengage. Start the car and turn on the a/c on to full. Then look at the a/c compressor and check to see if the clutch is engaging. You will see one of three things; 1-the clutch is fully engaged (most likely not), 2-the clutch is going on and off (this most likely be what you are experiencing), 3-or the clutch is not engaging at all. My guess is that you need a shot of freon.
^^^^^^^^^^^^^^^^
The hissing sound you are referrring to along with the "15 second drag" could be simply needing refrigerant,
**how's that? a hiss is not needing refrigerant but, because of a possible leak, WILL need refrigerant only after it gets repaired or, will be getting worse..

is not as the "drag" could be caused by the compressor engaging/disengaging/engaging.
**could be the clutch or belt slipping a bit..have even heard of a clutch slipping which could also be the sound made....

Your a/c system might be low causing the a/c clutch to engage and disengage.
**then, what he would hear is the clicking of the compresor in and out and not a hiss...while it is true that a low charge can result in the cycling of the a/c, i do not believe it is indicated here...

Start the car and turn on the a/c on to full. Then look at the a/c compressor and check to see if the clutch is engaging. You will see one of three things; 1-the clutch is fully engaged (most likely not), 2-the clutch is going on and off (this most likely be what you are experiencing), 3-or the clutch is not engaging at all. My guess is that you need a shot of freon
** i believe that he should first TRY and isolate the noise if possible....then, visually observe any junctions/connections to-from the components of the a/c and compresor and determine if any oily residue exists which would strongly indicate a leak that must be repaired...a set of gauges should be thrown on and after determining the ambient air temps, should observe reading on the gauges to determine if low charge...i think the noise he is hearing is either the belt or the ac compressor itself....
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