When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Need help with AC diagnosis low and high pressure readings attached
Hello everyone as the title says i need help with troubleshooting my ac problem , the ambient temperature is 53 Deg Celsius which is equal to 127 Fahrenheit , i checked the pressure on low and high side and found the following :
operating pressure :
High side pressure : 280 PSI
Low side pressure : 75 PSI
Static pressure :
150 PSI on both sides ( the pressure not matching with ambient temperature of 127 F ) Does that mean I'm low in charge ?
as per the Ambient Air Temperature-to-operating Pressure Table in Nissan service manual the readings for 104 Fahrenheit shall be as the following
high side : 176.9 - 265.4
Low side : 45.0 - 54.4
the max Ambient temp in the above table is 104 however the ambient temperature where I live is 127 Fahrenheit , the cooling from the ac is very minor and earlier i got better cooling till i got a leak recently , and replaced the evaporator along with the expansion valve .
kindly advise what could be the issue .
update 20th july 2020 :
i own another nissan altima 2015 model i took the reading today at 45 Deg Celsius ambient and compared it to my maxima readings and found the following :
Where in God's Earth are you located that the ambient temperature is 127 F?
Being familiar with cars in general, and Nissans in particular - I can tell you that no automobile AC system can comfortably combat that kind of heat.
i live in Kuwait its located in the middle east - its well known for its high climate .
i do not expect the ac to operate comfortably how ever i expect some temp reduction , i have an Altima 2015 and it preforms much better in this Temp .
in addition the ac was doing well till the recent evaporator replacement along with exp. valve done at the mechanic i took the car back to him and hes claiming that i have a bad compressor :/ ( i doubt that i have a bad compressor as the high pressure side seems fine to me only the low side seems high )
Pressure is too high, is your compressor coming on did you recently recharge it?
yes due to refrigerant leak i recently replaced the evap along with the expansion valve and recharged the system at the mechanic .
with regards to the compressor ill confirm if it engage by inspecting it visually , however i think its engaging as the high pressure side is increasing from the static pressure of 150 PSI to operating pressure of 275 PSI mentioned above .
in addition i noted today that as the engine revs up to 2000 rpm the cooling is perfectly fine , when ever rpm drops cooling decreases .
further i own another nissan altima 2015 model it took the reading today at 45 Deg and compared it to my maxima readings and found the following :
I agree with MaximusN8. You seem overcharged! Too much of a good thing 74psi on the low side is too high (according to your gauges)
PS I don't know how much AMAZON charges to ship but you should trade your 2 X 4 for some new hood lift supports
The correct refrigerant charge should be verified. 150 psi static sounds a little high.
And there is really no way to determine the charge accurately other than by weight.
Originally Posted by LtLeary
I agree with MaximusN8. You seem overcharged! Too much of a good thing 74psi on the low side is too high (according to your gauges)
PS I don't know how much AMAZON charges to ship but you should trade your 2 X 4 for some new hood lift supports https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
you were correct guys I vacuumed the refrigerant and refilled with the correct quantity, its way better now . Thanks for your support .
i took the car back to him and hes claiming that i have a bad compressor :/ ( i doubt that i have a bad compressor as the high pressure side seems fine to me only the low side seems high ) 
