G37 09 A/C blowing hot ait when idle
08-18-2015, 07:50 AM
#1
G37 09 A/C blowing hot ait when idle
Dear Gents
My g37 sedan 2009 A/C blowing hot air when idle (clutch engaged) but not all the time and when i move the a/c will work fine but some times it will take more time to become cold so i turn the ac off & turn it on again so the air will be cold again more fast.
i went to ac technician and found that Freon is full but the pressure is 50-60 when it is blowing hot air and around 110-120 when it is blowing cold
i gave my car to the dealer to check it but sadly the ac was working fine so they said its OK
the fans working fine also temp is OK.
what you think the coz of the pressure become low and this is making the air hot. this issue happened 2 months ago and the millage is 130.000 KM
Do you think compressor control valve is the reason or will affect?
My g37 sedan 2009 A/C blowing hot air when idle (clutch engaged) but not all the time and when i move the a/c will work fine but some times it will take more time to become cold so i turn the ac off & turn it on again so the air will be cold again more fast.
i went to ac technician and found that Freon is full but the pressure is 50-60 when it is blowing hot air and around 110-120 when it is blowing cold
i gave my car to the dealer to check it but sadly the ac was working fine so they said its OK
the fans working fine also temp is OK.
what you think the coz of the pressure become low and this is making the air hot. this issue happened 2 months ago and the millage is 130.000 KM
Do you think compressor control valve is the reason or will affect?
Last edited by the dreame; 08-18-2015 at 07:56 AM.
08-18-2015, 08:15 AM
#2
Climate control systems are tough. They are even tougher trying to diagnose on paper. You're dealer should go through the FSM flow charts for diagnosis. Did they charge you for the services?
Shooting from the hip, I would say check the easiest thing first. When was the last replacement of your cabin filter? A saturated cabin filter can cause the evaporator to not receive adequate air flow. Without that air flow, the evaporator can freeze. Frozen evaporator = no cool air. As the vehicle gains speed, more air can be forced past the evaporator helping to partially thaw out. Start there.
Another check you can perform yourself, is to see if the A/C clutch is engaged while you are idling with A/C settings in the on position. If the clutch if freewheeling, a component of the system is attempting to save your compressor. e.g. pressure sensor on condenser.
You gave values for gauge readings. I assume the units are in kPa? Also, were you given readings for both the high and low pressure sides?
Shooting from the hip, I would say check the easiest thing first. When was the last replacement of your cabin filter? A saturated cabin filter can cause the evaporator to not receive adequate air flow. Without that air flow, the evaporator can freeze. Frozen evaporator = no cool air. As the vehicle gains speed, more air can be forced past the evaporator helping to partially thaw out. Start there.
Another check you can perform yourself, is to see if the A/C clutch is engaged while you are idling with A/C settings in the on position. If the clutch if freewheeling, a component of the system is attempting to save your compressor. e.g. pressure sensor on condenser.
You gave values for gauge readings. I assume the units are in kPa? Also, were you given readings for both the high and low pressure sides?
08-19-2015, 01:02 AM
#3
Climate control systems are tough. They are even tougher trying to diagnose on paper. You're dealer should go through the FSM flow charts for diagnosis. Did they charge you for the services?
Shooting from the hip, I would say check the easiest thing first. When was the last replacement of your cabin filter? A saturated cabin filter can cause the evaporator to not receive adequate air flow. Without that air flow, the evaporator can freeze. Frozen evaporator = no cool air. As the vehicle gains speed, more air can be forced past the evaporator helping to partially thaw out. Start there.
Another check you can perform yourself, is to see if the A/C clutch is engaged while you are idling with A/C settings in the on position. If the clutch if freewheeling, a component of the system is attempting to save your compressor. e.g. pressure sensor on condenser.
You gave values for gauge readings. I assume the units are in kPa? Also, were you given readings for both the high and low pressure sides?
Shooting from the hip, I would say check the easiest thing first. When was the last replacement of your cabin filter? A saturated cabin filter can cause the evaporator to not receive adequate air flow. Without that air flow, the evaporator can freeze. Frozen evaporator = no cool air. As the vehicle gains speed, more air can be forced past the evaporator helping to partially thaw out. Start there.
Another check you can perform yourself, is to see if the A/C clutch is engaged while you are idling with A/C settings in the on position. If the clutch if freewheeling, a component of the system is attempting to save your compressor. e.g. pressure sensor on condenser.
You gave values for gauge readings. I assume the units are in kPa? Also, were you given readings for both the high and low pressure sides?
i replaced the cabin air filter since i filt the heat but nothing changed i think because the old one in good condition
the a/c clutch is engaged as i know and i am turning off & on ac button many times while the car stopped and sometimes changed to cold & sometimes not
I think the unit in KPA for low pressure side. When the tech. checked the Freon pressure its 50-60 and the air is hot, i restarted the car again same time and the pressure increased to 110-120 and the air is little cold, it will be more cold after i drive the car(dual fans working OK)
03-31-2017, 11:52 PM
#4
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thanks dear fro the replay
i replaced the cabin air filter since i filt the heat but nothing changed i think because the old one in good condition
the a/c clutch is engaged as i know and i am turning off & on ac button many times while the car stopped and sometimes changed to cold & sometimes not
I think the unit in KPA for low pressure side. When the tech. checked the Freon pressure its 50-60 and the air is hot, i restarted the car again same time and the pressure increased to 110-120 and the air is little cold, it will be more cold after i drive the car(dual fans working OK)
i replaced the cabin air filter since i filt the heat but nothing changed i think because the old one in good condition
the a/c clutch is engaged as i know and i am turning off & on ac button many times while the car stopped and sometimes changed to cold & sometimes not
I think the unit in KPA for low pressure side. When the tech. checked the Freon pressure its 50-60 and the air is hot, i restarted the car again same time and the pressure increased to 110-120 and the air is little cold, it will be more cold after i drive the car(dual fans working OK)
There's a TSB for this issue, dealer needs to update the ECU. It's ITB10-051
04-09-2017, 08:52 AM
#5
I kind of feel like you answered your own question OP with your explanation of what happens, and i don't say that in a negative way. I just got a 2010 G37x, won't be ready for pickup til tuesday, so i have not dived into the engine design yet first hand, just taking a guess here, but most AC compressors are engine accessories. The engagement of the clutch, and dis-engagement of the clutch defines the accessories to engage as well for the most part. Other then that, that's what goes through my head as a starting point. Pressure is good, freon is good, brake down the system to find the point of repair.
04-09-2017, 10:30 AM
#6
Mine will do this at a stop light if the rpm's drop below 600. Mine is an automatic.
Might try reading this....
https://www.myg37.com/forums/g37-sed...w-owner-5.html
Might try reading this....
https://www.myg37.com/forums/g37-sed...w-owner-5.html
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