What Causes Oil Leakage in an Automotive Air Conditioning Compressor?

[DeKathryn]

Oil leakage in an automotive air conditioning compressor can be attributed to the following reasons: 1. Oil leakage at the front or rear crankshaft oil seal: First, inspect the exterior for any signs of oil leakage, paying special attention to the front and rear crankshaft oil seals. A cracked, damaged, or aged front crankshaft oil seal, or wear on the contact surface between the crankshaft pulley and the oil seal, can cause oil leakage at the front of the crankshaft. Similarly, a cracked or damaged rear crankshaft oil seal, or an excessively small oil return hole in the rear main bearing cap obstructing oil return, can lead to oil leakage at the rear of the crankshaft. 2. High pressure in the crankcase: If oil is leaking from both the front and rear oil seals, or if oil is seeping from multiple areas such as the front and rear valve covers, front and rear valve lifter chambers, oil filter, and oil pan gasket without a clear source, the crankcase ventilation system should be inspected. Clean the crankcase ventilation pipes, and particularly check if the PCV valve is malfunctioning due to carbon buildup or sticky deposits causing it to stick.