A/C blows warm below 2000rpm
#1
A/C blows warm below 2000rpm
Just to start I want to say thank you for any advice, and or help in advance.
I have a 2002 s2000 it blows warm air at idle, but cold air above 2500rpms. This is true even when the car is sitting and I rev it to above 2500rpm, the car does not need to be moving to achieve cold air to blow form the A/C. Its been doing this since December, but I wasn't concerned with it because well... it was nice outside so top down was more than enough. However summer is here and its unbearably hot now days, and too sunny for even trying top down driving. Im not sure what could be wrong with the A/C system so I gathered some info that may or may not be relevant to my issue. I was able to record some low side pressure readings, but unable to fit my gauge on the high side port. From what I can discern from research, it might be a faulty expansion valve. If high side readings are needed ill buy a reader that fits on it to record the pressure.
90 degrees Fahrenheit outside with 62% humidity during the tests. A/C set to MAX, at coldest setting with recirculation on.
Cold start Low side pressure- 35-47psi @1500rpm
Engine temp now at 2 bars- 58psi @1250rpm
Still at 2 bars- 62psi @1100rpm
Warmed up to 3 bars 65psi @900-1000rpm
60psi @1500rpm
45-53psi @2000rpm (fluctuates a bit) the A/C is starting to cool
40psi @2500rpm (stable) A/C blowing cold air.
I have a 2002 s2000 it blows warm air at idle, but cold air above 2500rpms. This is true even when the car is sitting and I rev it to above 2500rpm, the car does not need to be moving to achieve cold air to blow form the A/C. Its been doing this since December, but I wasn't concerned with it because well... it was nice outside so top down was more than enough. However summer is here and its unbearably hot now days, and too sunny for even trying top down driving. Im not sure what could be wrong with the A/C system so I gathered some info that may or may not be relevant to my issue. I was able to record some low side pressure readings, but unable to fit my gauge on the high side port. From what I can discern from research, it might be a faulty expansion valve. If high side readings are needed ill buy a reader that fits on it to record the pressure.
90 degrees Fahrenheit outside with 62% humidity during the tests. A/C set to MAX, at coldest setting with recirculation on.
Cold start Low side pressure- 35-47psi @1500rpm
Engine temp now at 2 bars- 58psi @1250rpm
Still at 2 bars- 62psi @1100rpm
Warmed up to 3 bars 65psi @900-1000rpm
60psi @1500rpm
45-53psi @2000rpm (fluctuates a bit) the A/C is starting to cool
40psi @2500rpm (stable) A/C blowing cold air.
#2
Just to start I want to say thank you for any advice, and or help in advance.
I have a 2002 s2000 it blows warm air at idle, but cold air above 2500rpms. This is true even when the car is sitting and I rev it to above 2500rpm, the car does not need to be moving to achieve cold air to blow form the A/C. Its been doing this since December, but I wasn't concerned with it because well... it was nice outside so top down was more than enough. However summer is here and its unbearably hot now days, and too sunny for even trying top down driving. Im not sure what could be wrong with the A/C system so I gathered some info that may or may not be relevant to my issue. I was able to record some low side pressure readings, but unable to fit my gauge on the high side port. From what I can discern from research, it might be a faulty expansion valve. If high side readings are needed ill buy a reader that fits on it to record the pressure.
90 degrees Fahrenheit outside with 62% humidity during the tests. A/C set to MAX, at coldest setting with recirculation on.
Cold start Low side pressure- 35-47psi @1500rpm
Engine temp now at 2 bars- 58psi @1250rpm
Still at 2 bars- 62psi @1100rpm
Warmed up to 3 bars 65psi @900-1000rpm
60psi @1500rpm
45-53psi @2000rpm (fluctuates a bit) the A/C is starting to cool
40psi @2500rpm (stable) A/C blowing cold air.
I have a 2002 s2000 it blows warm air at idle, but cold air above 2500rpms. This is true even when the car is sitting and I rev it to above 2500rpm, the car does not need to be moving to achieve cold air to blow form the A/C. Its been doing this since December, but I wasn't concerned with it because well... it was nice outside so top down was more than enough. However summer is here and its unbearably hot now days, and too sunny for even trying top down driving. Im not sure what could be wrong with the A/C system so I gathered some info that may or may not be relevant to my issue. I was able to record some low side pressure readings, but unable to fit my gauge on the high side port. From what I can discern from research, it might be a faulty expansion valve. If high side readings are needed ill buy a reader that fits on it to record the pressure.
90 degrees Fahrenheit outside with 62% humidity during the tests. A/C set to MAX, at coldest setting with recirculation on.
Cold start Low side pressure- 35-47psi @1500rpm
Engine temp now at 2 bars- 58psi @1250rpm
Still at 2 bars- 62psi @1100rpm
Warmed up to 3 bars 65psi @900-1000rpm
60psi @1500rpm
45-53psi @2000rpm (fluctuates a bit) the A/C is starting to cool
40psi @2500rpm (stable) A/C blowing cold air.
#3
So your pressures on the low side are definitely high. A/c system issues can often be diagnosed by pressures however need info on your high side readings. Normally an expansion valve will cause low, low side pressure... here is a chart that shows a pressure diagnostic chart. Don’t mind the fact it had a/c dye spilled on it... unfortunately I would not be surprised if it has a failing compressor as that is an extremely common issue on almost all hondas and unfortunately s2000s aren’t an exception. As you can see from the chart if the high side is low it’s almost a guarantee
#4
My A/C compressor turns on, the clutch does spin, but in your opinion even without knowing the high side pressure in your opinion the compressor is the likely culprit because its beginning to fail? Even with the accompanying symptoms? I understand this is just your diagnosis without all the info you really need, but still thanks. I might just buy a used compressor to get it done asap.
#5
My A/C compressor turns on, the clutch does spin, but in your opinion even without knowing the high side pressure in your opinion the compressor is the likely culprit because its beginning to fail? Even with the accompanying symptoms? I understand this is just your diagnosis without all the info you really need, but still thanks. I might just buy a used compressor to get it done asap.
is there any specific reason why you cant get a high side reading other than your adapter doesn't fit? Have you thought about going to harbor freight or a parts store and picking up a cheap set of gauges?
#7
AC Compressor going out
Hi @prodigalmichael, I have the exact same issues that you're explaining. I just took my car to an AC shop, and they said the compressor is the culprit and that it's on it's way out. I still get cold air when driving above 2k RPM like you, so it's not an immediate repair, but eventually the compressor will go out completely. They quoted me $2,500 for parts and labor using genuine Honda parts, or $1,600 for an aftermarket compressor. This is in Hawaii where stuff costs more, so take that with a grain of salt.
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