汽车专业实用英语 作者 陈晟闽 02-air induction systmtem.ppt

Objectives Explain the operation of the components in the air induction system. Describe how the engine creates vacuum and how vacuum is used to operate and control many automotive devices. Inspect and troubleshoot vacuum and air induction systems. Objectives Explain the operation of exhaust system components. Properly perform an exhaust system inspection, and service and replace exhaust system components. Explain the purpose and operation of a turbocharger. Objectives Inspect a turbocharger, and describe some common turbocharger problems. Explain supercharger operation, and identify common supercharger problems. Air Induction System Functions Air induction systems Silence intake air noise. Heat or cool the intake air. Provide air for the engine to operate. Filter the air. Monitor airflow temperature and density. Operate the PCV system. Provide air for the air injection system. Air Induction Components Intake Manifold Components A late-model intake manifold for a V-6 engine Engine Vacuum It is produced by the downward movement of the piston on the intake stroke. It is pressure that is less than atmospheric pressure. It is usually measured in millimeters of mercury (mm/Hg) or inches of mercury (in/Hg). Vacuum Problem Diagnosis Check hoses for improper routing. Look for kinks and tears in vacuum lines. Check for vacuum hoses routed near hot spots. Look for evidence of oil or transmission fluid in vacuum hose connections. Inspect vacuum system components for damage. Exhaust System Components Exhaust manifold Exhaust pipe and seal Catalytic converter Muffler Resonator Tailpipe Heat shields Clamps, brackets, and hangers Exhaust gas oxygen sensors Exhaust System Components An exhaust system for an OBD-II vehicle Exhaust System Inspection Items Holes, road damage, and split seams Kinks or dents Discoloration or rust Broken or missing hangers Loose tailpipes or other components Signs of catalytic converter overheating: Bluish or brownish converter shell Common Exhaust Wo