Unstable AC Low Pressure Reading, Stable High Pressure

[G A]

Working on fixing my girlfriend’s 2010 Civic air conditioner.

Of all the material I have gone through to diagnose A/C issues, I have yet to find the same case that I’m running into, as most guides just diagnose with just a given PSI for high or low side. Many guides don’t even acknowledge the effects of ambient temperature.

Main Points:
Not enough cooling (here in Vegas in July it’s already hard to get)
AC Compressor Engages
Low-Side needle was very unstable, while High-Side was stable
System was ~38 on low side, and 200 on high side upon first measurements (in ~105 F), engine brought up to temp
Per mechanic friend’s recommendation: Tried charging the system up to 250 on the high side to see if I could get it there, and I did successfully
Low side needle still highly unstable (rapid shaking and also varied what it was centered around between 50-60 psi)

Friend’s Suggestion: Probably a leak somewhere in the system and/or a clogged expansion valve.

Waiting to look at the car again to check the UV dye I put into the system and look for leaks.

Thoughts?

• This topic was modified 4 years, 5 months ago by G A.

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