Overheating problems with A/C on
08-10-2012, 08:15 PM
#63
From your earlier description is sounds like you were describing what the blue arrow is pointing to. The Red arrow shows the Safety Valve. The Blue Arrow shows an optional port for a pressure switch. It's just and aluminum plug that is held in by a snap ring.
The switch can be located on the back of the compressor or on the Line depending on the year and how the system is set up.
The switch can be located on the back of the compressor or on the Line depending on the year and how the system is set up.
08-10-2012, 09:14 PM
#66
Well guys, I got everything back together and charged. It blows cold as hell but I still have that damn PPPSSHHHH sound. It really freaks me out because I replace everything that has to do with the a/c system except the evaporator. New compressor, condenser, accumulator, orifice tube.
So I figure the sound is the blow off valve on the back of the compressor but I can't figure out why in the hell it would be relieving pressure. I know that the fans are doing a great job at pulling air so I don't think they are a problem. Any ideas?
So I figure the sound is the blow off valve on the back of the compressor but I can't figure out why in the hell it would be relieving pressure. I know that the fans are doing a great job at pulling air so I don't think they are a problem. Any ideas?
08-10-2012, 09:28 PM
#67
It has never done it at idle since all the new parts are in. It only happens while going through the gears from a stop light or stop sign. Just real casual driving. Usually happens after the 1-2 shift or 2-3 shift.
I drive it on the freeway to work everyday and it does it about every 30 seconds or so. It's so damn annoying. When on the freeway, converter is locked, just cruising at 65, 1800rpms and it ppppsshhhh's in very short bursts. I can feel it in the pedal like it is putting a load on the motor when it happens.
I will try and mount a camera in the truck and drive it normal. Hopefully you will be able to hear it from inside that cab
I drive it on the freeway to work everyday and it does it about every 30 seconds or so. It's so damn annoying. When on the freeway, converter is locked, just cruising at 65, 1800rpms and it ppppsshhhh's in very short bursts. I can feel it in the pedal like it is putting a load on the motor when it happens.
I will try and mount a camera in the truck and drive it normal. Hopefully you will be able to hear it from inside that cab
08-10-2012, 09:44 PM
#68
It's hard to explain but Under low pressure, R134a is compressed into a liquid. As it goes through the system and is pressurized to High pressure by the compressor and it becomes a gas from the heat caused by compressing it. By pushing it through the condenser it cools that gas back into a liquid. As it goes through the system it hits the Dryer, The dry has desiccants that attract any moisture in the system and remove them so that you don't get Ice crystals that can damage the system. It then goes through a thermal expansion valve or an orifice tube that regulates the pressure and turns that side of the system it to low Pressure. It then passes through the evaporator as a cool liquid around 32* and as the fan blows air across the evaporator the heat in side the cabin is enough to make the refrigerant heat back up and boil again turning from liquid to gas again. Then the cycle starts all over again.
So what your hearing might actually be normal as the refrigerant is passing through the orifice valve. It could also be the system as the compressor is cycling on and off if it over pressurizes.
So what your hearing might actually be normal as the refrigerant is passing through the orifice valve. It could also be the system as the compressor is cycling on and off if it over pressurizes.
08-10-2012, 09:59 PM
#70
I would watch the AC pressure and the Clutch signal command when this occurs.
See if it's being over pressurised causing the compressor clutch to engage and dis-engage.