94 civic cools @ 55mph, any slower none. some history: replaced discharge line that was leaking, compressor seems to be working, replaced expansion valve, and dryer filter. evacuated the system (drew vac. for 2hr. @ 30in. ) recharged with oil and 1.5 lbs. r134. not cold. performance tested system. rpm1500+, ac full on, windows open. used fan at front of car for added cooling. 10+ min. running. gage readings were: low side 55 to 60 (above norm.) high side 155 to 160 (below norm.) after shutting ac off, gages read 55 low side 120 high side. I suspect the compressor is failing. any help welcome.

 

Outside temp during performance test?

Are the condenser fins clogged with road debris? Does the condenser fan run?

But yeah, at this early juncture, it does sound like the compressor may be toast.

 

if you're sitting in your car idling, the cooling system doesn't work but if you rev the engine while stationary to 3K, does it cool? Slipping clutch perhaps?

 

Outside temp was 78degrees, humidity aprx. 60%. Condenser fins look clear, condenser fan is working well. I did tighten drive belt some, but this made no difference.

 

at sitting still, no cooling at any rpm

 

Yeah, I think your compressor is toast.