A/C System Performance

WARNING: This page is about a different car, the 1997 Oldsmobile Cutlass Supreme. However, it is still accessible from the selected car via links, so may be relevant.

Place vehicle out of direct sun light. Ensure garage (outside) ambient air temperature is 70-90°F (21-32 °C). Install A/C manifold gauge set. Go to next step.
Close all vehicle doors and windows. Start engine and allow it to reach normal operating temperature. Select AUTO mode and set temperature to 60°F (15°C). Run engine for 5 minutes to allow A/C system to stabilize. Blower motor should run at high speed and cold air should flow from dash registers. Record high-side and low-side pressures. Go to next step.
Feel liquid line on both sides of expansion tube. Temperature between sides should be noticeably different. Pressure readings should be within correct range. See A/C SYSTEM PERFORMANCE PRESSURE SPECIFICATIONS . Normal discharge air temperature for a properly functioning A/C system is about 20°F (7°C) cooler than ambient air temperature.
Automatic A/C-heater refrigerant system operates the same as manual system. If A/C system does not operate as described, see the A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL article.

A/C SYSTEM PERFORMANCE PRESSURE SPECIFICATIONS ⁽¹⁾

Ambient Temp. °F (°C)

High Side psi (kg/cm² )

Low Side psi (kg/cm² )

70 (21)

290 (20.4)

37 (2.6)

80 (27)

340 (23.9)

42 (3.0)

90 (32)

390 (27.4)

49 (3.4)

100 (38)

445 (32.0)

60 (4.2)

⁽¹⁾	Maximum pressures with relative humidity at 60 percent and engine speed at 2000 RPM.