What are the symptoms of oil shortage in an automotive air conditioning compressor?
2 Answers
What phenomena occur when an air conditioning compressor lacks oil: Low efficiency: Reduced efficiency, resulting in very poor cooling (or heating). The compressor frequently goes into protection mode (increased wear due to oil shortage leads to lower compressor temperature). Seizure: The compressor often seizes, especially when there is a significant temperature difference between indoor and outdoor environments. The air conditioning compressor functions to compress and drive the refrigerant in the air conditioning refrigeration cycle. It is typically installed in the outdoor unit. The compressor draws refrigerant from the low-pressure area, compresses it, and delivers it to the high-pressure area for cooling and condensation. Heat is dissipated into the air through the radiator, and the refrigerant changes from a gaseous to a liquid state, with increased pressure.
I've been driving for over a decade, and last summer I encountered an issue with insufficient oil in the air conditioning compressor. When I first turned on the AC, there was a harsh screeching noise from the car, like metal grinding; the cooling was also slower, and after half an hour, the car was still uncomfortably hot. After inspection, it turned out the oil level was too low, causing the internal components of the compressor to run dry, increasing friction and producing noise, and making it prone to overheating and seizing. If not repaired promptly, it could damage the entire system, and replacing a compressor can be costly. Since then, I've made it a habit to check the oil level at a repair shop before summer each year; I also avoid frequently turning the AC on and off during daily driving to reduce wear. Insufficient oil in the AC not only affects comfort but can also distract drivers on hot days, which is quite dangerous—don’t wait until a small issue becomes a big problem before taking action.
