Exhaust Gas Recirculation (EGR) System Cleaning

CAUTION: Avoid breathing fumes and swallowing EGR exhaust deposits when removing components for cleaning as bodily injury may result.

The EGR system should be inspected and cleaned whenever the EGR valve is removed, or during regularly scheduled EGR system maintenance. This routine inspection and cleaning will insure that the EGR system will function properly under all operating conditions. An EGR System Diagnosis should be performed if required by engine performance or engine driveability symptoms and no PCM DTCs are set.

Proper EGR system service consists of the following procedures:
1. Clean and inspect the EGR pipe in the following manner:
^ Clean and inspect the pipe from the exhaust manifold to the EGR valve.
^ Clean and inspect the pipe from the water pump crossover to the throttle body spacer.
^ Clean and inspect the pipe for leaks.
2. If the EGR system is operating correctly, the EGR valve can be removed, inspected, cleaned and replaced. To remove the EGR for inspection and cleaning, use the following procedures:
2.1. Remove the EGR valve from the engine.
2.2. While holding the EGR valve in your hand, using a pencil eraser or other suitable soft instrument to depress the pintle several times. The pintle should move in and out smoothly, replace any valve that exhibits tendencies to stick.
2.3. While holding the EGR valve base in your hand, try to rotate the connector housing. Replace any valve that exhibits looseness.
2.4. While holding the EGR valve base in your hand, try to rotate the coil housing. Replace any valve that exhibits looseness.
2.5. Inspect the EGR valve pintle and seat for deposits. Use a cloth or other suitable soft device to remove deposits. Remove all loose particles. If deposits are such that pintle/base interface can't be cleaned adequately to allow pintle to seal against the seat, replace the valve. Damage to the powdered metal EGR valve base will occur if cleaned with solvents, sharp tools, wire brush/wheel or sand blasting. Cleaning by these methods is not recommended.
2.6. Inspect the passage in the Crossover Water Pump Housing for deposits. Remove all loose particles.




2.7. Replace the EGR valve on engine, using a new gasket.
3. Use the following procedures to inspect and clean the EGR Passages in the crossover water pump housing:
3.1. Remove the crossover water pump housing.
3.2. Remove 2 plugs (2) and clean the EGR passages with a wire brush. Remove all loose particles.
3.3. Put the crossover water pump housing back on the engine.
4. Wash-up after any contact with deposits from the EGR System.