Full load a/c
06-09-2016, 05:50 PM
#1
Racer
Thread Starter
It seems like the car shuts off the air-conditioning compressor briefly under full throttle. Does anyone know if our engines are programmed to do this? Load shedding in favor of maximum power like something they would do. It's quite noticeable right after you get into the car after it sits in the hot sun for a while.
06-09-2016, 06:52 PM
#4
this is interesting. by "full load" do you guys mean driving hard?
so I picked up my new 991.2 at the PEC in Atlanta 6 weeks ago and drove back to South Florida. On the first day's drive, after driving for about 4 hours or so, it felt like the A/C just stopped working on its own. this was while just cruising on the highway between 70 and 80 mph... outside temp was probably in the mid 80s.... so not particularly hard load... I was really flipped out that this would happen to a brand new car.... So I just turned it off for a couple of minutes and then turned it back on and it never quit again... but I have not had drives as long since to compare again.. is the A/C designed to behave like this? thank you
so I picked up my new 991.2 at the PEC in Atlanta 6 weeks ago and drove back to South Florida. On the first day's drive, after driving for about 4 hours or so, it felt like the A/C just stopped working on its own. this was while just cruising on the highway between 70 and 80 mph... outside temp was probably in the mid 80s.... so not particularly hard load... I was really flipped out that this would happen to a brand new car.... So I just turned it off for a couple of minutes and then turned it back on and it never quit again... but I have not had drives as long since to compare again.. is the A/C designed to behave like this? thank you
06-09-2016, 08:13 PM
#6
Racer
Thread Starter
I think it's supposed to cut out at full throttle. I agree anything else would be suspect. I would for floor it a few seconds and then for a few seconds later get a blast of warm air from the vents then it cools down after I back off. I knew you could steer these cars with your right foot but I didn't know we had a multi function gas pedal!
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06-10-2016, 10:36 AM
#8
Years ago the mechanics to turn off the AC when the engine was under a load were where either a vacuum switch (no vacuum you are under load) or a micro switch on throttle linkage. With electronic engine management its done by either RPM or 'load' in the DME.
This could be the AC systems sensors designed to turn off the AC under certain conditions.
For example:
A) a temperature sensor in the evaporator core will turn off the system or comp clutch when the core temperature nears freezing. OR
B) a low pressure switch on the suction side will turn off the system or comp clutch when pressures drop below a certain set point (however usually not found Porsche systems that use a TEV system.
OR
If you mean by " it felt like the A/C just stopped working "
A) The vents stopped blowing air in the cockpit, could be the evaporator core froze up reducing the volume of air, or the evaporator core froze up and the vent temperatures rose. In this scenario the evap core freeze sensor was not doing its job. By turning off the AC for awhile the evap core's ice will melt and things return to normal.
B) You got to find the gremlin causing the problem by further describing what was going on, such as: no air from vents, out clutch hub on ac comp stopped turning, etc.
On the first day's drive, after driving for about 4 hours or so, it felt like the A/C just stopped working on its own. this was while just cruising on the highway between 70 and 80 mph. So I just turned it off for a couple of minutes and then turned it back on and it never quit again
For example:
A) a temperature sensor in the evaporator core will turn off the system or comp clutch when the core temperature nears freezing. OR
B) a low pressure switch on the suction side will turn off the system or comp clutch when pressures drop below a certain set point (however usually not found Porsche systems that use a TEV system.
OR
If you mean by " it felt like the A/C just stopped working "
A) The vents stopped blowing air in the cockpit, could be the evaporator core froze up reducing the volume of air, or the evaporator core froze up and the vent temperatures rose. In this scenario the evap core freeze sensor was not doing its job. By turning off the AC for awhile the evap core's ice will melt and things return to normal.
B) You got to find the gremlin causing the problem by further describing what was going on, such as: no air from vents, out clutch hub on ac comp stopped turning, etc.
06-10-2016, 12:45 PM
#9
Banned
Years ago the mechanics to turn off the AC when the engine was under a load were where either a vacuum switch (no vacuum you are under load) or a micro switch on throttle linkage. With electronic engine management its done by either RPM or 'load' in the DME.This could be the AC systems sensors designed to turn off the AC under certain conditions.
For example:
A) a temperature sensor in the evaporator core will turn off the system or comp clutch when the core temperature nears freezing. OR
B) a low pressure switch on the suction side will turn off the system or comp clutch when pressures drop below a certain set point (however usually not found Porsche systems that use a TEV system.
OR
If you mean by " it felt like the A/C just stopped working "
A) The vents stopped blowing air in the cockpit, could be the evaporator core froze up reducing the volume of air, or the evaporator core froze up and the vent temperatures rose. In this scenario the evap core freeze sensor was not doing its job. By turning off the AC for awhile the evap core's ice will melt and things return to normal.
B) You got to find the gremlin causing the problem by further describing what was going on, such as: no air from vents, out clutch hub on ac comp stopped turning, etc.
For example:
A) a temperature sensor in the evaporator core will turn off the system or comp clutch when the core temperature nears freezing. OR
B) a low pressure switch on the suction side will turn off the system or comp clutch when pressures drop below a certain set point (however usually not found Porsche systems that use a TEV system.
OR
If you mean by " it felt like the A/C just stopped working "
A) The vents stopped blowing air in the cockpit, could be the evaporator core froze up reducing the volume of air, or the evaporator core froze up and the vent temperatures rose. In this scenario the evap core freeze sensor was not doing its job. By turning off the AC for awhile the evap core's ice will melt and things return to normal.
B) You got to find the gremlin causing the problem by further describing what was going on, such as: no air from vents, out clutch hub on ac comp stopped turning, etc.