High Side AC pressure when moving?
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From: Elizabethtown, PA
High Side AC pressure when moving? My AC system is BMW evaporator and receiver drier, and C6 corvette compressor and C5 condenser.
The ac is working but the high side dips way down to like 100 while driving. At idle it will cycle depending on the fan operation from like 150-220 temps are in the low-mid 70s with high humidity.
What should I see when going down the road? 180-200?
The ac is working but the high side dips way down to like 100 while driving. At idle it will cycle depending on the fan operation from like 150-220 temps are in the low-mid 70s with high humidity.
What should I see when going down the road? 180-200?
Thread Starter
TECH Enthusiast
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Joined: Apr 2010
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From: Elizabethtown, PA
It would seem the air vent temp is what matters most. I added a few more ounces today, it did pick the pressure up a bit.
It's very conflicting. Everything I've read so far, everyone wants to throw around numbers, but they all seem arbitrary and/or too many environmental/system variances to go by some magic number.
At 50mph, fan in the middle, recirc on, vent temps were 42 degrees in 82 degree weather, high side PSI was 140 after about 4-5 minutes of driving.
Hopefully when it's 92 - 95 those temps will be in the upper 40's. It is whatever it is, at this point
It's very conflicting. Everything I've read so far, everyone wants to throw around numbers, but they all seem arbitrary and/or too many environmental/system variances to go by some magic number.
At 50mph, fan in the middle, recirc on, vent temps were 42 degrees in 82 degree weather, high side PSI was 140 after about 4-5 minutes of driving.
Hopefully when it's 92 - 95 those temps will be in the upper 40's. It is whatever it is, at this point
General rule of thumb... outside temp x 2.2 = high pressure. (The 2.2 can change from 2.1 to 2.4 depending on who you listen too or read)
Say outside temp is 80 degrees x 2.2 = 176 psi on the high side
I generally start at that.. but as you found, many answers.... and that number can change due to variables, type of system, and refrigarents used. 134a generally has a higher pressure than R12.. that is why I start low and add if needed.
BC
Say outside temp is 80 degrees x 2.2 = 176 psi on the high side
I generally start at that.. but as you found, many answers.... and that number can change due to variables, type of system, and refrigarents used. 134a generally has a higher pressure than R12.. that is why I start low and add if needed.
BC
