TECHNICAL SERVICE BULLETIN: AIR INTAKE SYSTEM CLEANING, PCV VALVE & AIR FILTER REPLACEMENT DUE TO OIL CONTAMINATION - This bulletin provides information regarding the air intake system which may become contaminated with oil due to a faulty Positive Crankcase Ventilation (PCV) check valve on some 2021-2022MY Sorento (MQ4a) vehicles equipped with Theta III 2.5L T-GDI engine, produced from September 10, 2020 through October 2, 2021, which may allow engine oil to enter the air intake system and contaminate the engine air filter with oil.
