A/C - Delayed Cooling After Engine Start Up
87chevy22Number: 88-80-1B
Section: 1B
Date: NOV., 1987
Subject: DELAYED A/C COOLING AFTER ENGINE START UP
Model and Year: ALL VEHICLES WITH V5 COMPRESSOR
TO: ALL CHEVROLET DEALERS
The V5 is a variable displacement, five-cylinder compressor that automatically adjusts displacement to match air conditioning demand under all conditions. A control valve, located in the rear of the compressor, regulates the compressor capacity.
The V5 compressor runs continuously in the A/C mode except during periods when over-ridden by A/C system control switches (Wide Open Throttle-WOT, etc.). Because the compressor is operating continuously, the engine will perform more smoothly due to lack of clutch cycling.
Due to its variable displacement feature, special caution is necessary when diagnosing insufficient cooling conditions with the V5 compressor.
It is normal for liquid refrigerant to collect in the compressor crankcase during periods of shutdown, therefore, cooling action may be delayed up to two (2) minutes until the refrigerant is pumped from the crankcase.
If you experience a delay in cooling upon start-up beyond two (2) minutes, and the normal service manual procedure for A/C compressor clutch and electrical engine cooling fan operation has been accomplished, follow the procedure outlined below:
1. operate the A/C system by setting to Norm A/C mode and high blower.
2. Be sure the compressor clutch has engaged and that the electrical engine cooling fan is operating.
3. Idle the engine for two (2) minutes with the A/C system operating.
4. If no cooling, run the engine at approximately 3000 rpm for one (1) minute with the A/C system operating.
5. If no cooling, change the mode control to Vent position for one (1) minute at idle.
6. Set A/C system back to Norm A/C mode, then run the engine at approximately 3000 rpm for one (1) minute with the A/C system operating.
7. If no cooling, drive the car in a normal manner for five (5) minutes with the A/C operating.
8. If there is still no cooling, discharge the refrigerant system, check orifice tube installation, evacuate, and recharge. The refrigerant should be introduced into the accumulator-dehydrator as rapidly as possible in liquid form. When using the small individual cans of refrigerant, the can should be turned upside down to accomplish the rapid recharge.
9. Check for proper cooling. If lack of cooling persists, remove and replace the compressor.