Exhaust Gas Recirculation: Service and Repair

EGR VALVE INSPECTION AND CLEANING

CAUTION: If EGR passages in the intake manifold indicate excessive build-up of carbon deposits, the passages should be cleaned. Care should be taken to ensure that all loose particles are completely removed to prevent them from clogging the EGR valve, or from being ingested into the engine. Do not use chemicals or solvents to clean the EGR valve or intake manifold passages since chemicals may cause damage to the system. Wear approved eye protection for this cleaning procedure, to avoid possible injury to the eyes.

Clean the EGR valve as follows:

1. Disconnect the vacuum hose from the EGR valve. Remove the EGR valve-to-manifold retaining bolts, and the control valve.
2. Carefully plug the EGR ports into the intake manifold with a clean shop towel or other suitable cloth. This will prevent debris from falling into the intake port.
NOTE: Be sure to remove the cloth from the EGR port before installing the valve. Use compressed air to remove small debris.
3. With a wire wheel, remove the exhaust deposits from the mounting surface of the EGR valve and around the valve.
4. Look for exhaust deposits in the valve outlet, remove deposits as needed.
5. Clean intake manifold mounting surface.
6. Install valve assembly using new gasket, and reconnect the vacuum hose.



EGR INTAKE PASSAGE CLEANING


When cleaning the intake manifold EGR passages, care should be taken to ensure that all loose particles are completely removed to prevent them from clogging the EGR valve, or from being ingested into the engine.

1. Disconnect the vacuum hose from the EGR valve. Remove the EGR valve-to-manifold retaining bolts, and the control valve (if applicable).
2. Remove the carbon deposits from EGR ports by hand using a suitable sharp tool.
3. Using compressed air, blow the EGR ports clean. Solvents should not be used to clean EGR valve or passages, since damage to the system may result.
4. Install EGR valve, using a new gasket, and reconnect the vacuum hose.




CAUTION: If EGR passages in the intake manifold indicate excessive build up of carbon deposits, the passages should be cleaned including passages under the throttle body. Care should be taken to ensure that all loose particles are completely removed to prevent them from clogging the EGR valve or from being ingested into the engine. DO NOT use chemicals or solvents to clean the EGR valve or intake manifold passages chemicals may cause damage to system.