Abstract: A cleaning solution, which is particularly useful in cleaning the air-intake system of an EGR-valve-equipped diesel engine, includes a high-polarity solvent and low polarity solvent. The solution may also include a surfactant, a fatty amide, and a functional ketone. The cleaning solution is applied to the air intake system while the diesel engine is running, thereby drawing the cleaning solution into the air intake system to clean the same. The EGR valve is removed and replaced with a vessel in which a pressure drop is created. The pressure drop creates sufficient vacuum so that cleaner may be administered into the air-intake duct of the vehicle.

Abstract: Disclosed is a method and a Volatile Organic Compound (VOC) cleaning composition for cleaning the air intake system of a engine, the cleaning composition comprising, a pyrrolidinone, an alcohol, and a VOC solvent. The Volatile Organic Compound (VOC) cleaning composition is used to clean contaminants from the plenum of an internal combustion engine by spraying or otherwise introducing the composition into the plenum.