There may be the following reasons for the Buick GL8 AC not cooling: 1. Refrigerant issue: The car's AC system consists of multiple metal pipes with small gaps between them, leading to slight refrigerant leakage. Additionally, the dryer in the car's AC system absorbs moisture and retains some refrigerant, so when the refrigerant level decreases to a certain point, the cooling capacity of the car's AC will diminish. In some models with dual-zone AC, insufficient cooling may result in hot air blowing from the vents. 2. Excessive contaminants in the compressor oil: This can clog the filter screen, reducing cooling efficiency, increasing resistance, and decreasing the flow of refrigerant to the expansion valve, leading to poor AC performance. Sometimes, if air enters the AC system, it can cause excessive pressure in the refrigerant lines, leading to poor refrigerant circulation and insufficient cooling. 3. Dryer tank issue: Its main function is to absorb moisture from the refrigerant to prevent excessive moisture from reducing cooling capacity. When the desiccant in the dryer tank becomes saturated, it can no longer filter out moisture. When the refrigerant passes through the expansion valve's throttle hole, due to the drop in pressure and temperature, the water in the refrigerant may freeze in the small hole, causing poor refrigerant flow, increased resistance, or complete blockage.
