EGR System Cleaning
WARNING: This page is about a different car, the 2003 Cadillac Seville and 2003 Cadillac DeVille. However, it is still accessible from the selected car via links, so may be relevant.
WARNING:
Avoid breathing fumes and swallowing EGR exhaust deposits when removing components for cleaning as bodily injury may result.
Whenever the Exhaust Gas Recirculation (EGR) valve is removed the EGR system should be inspected and cleaned if necessary. This will ensure that the EGR system will function properly under all operating conditions. Proper EGR system service consists of the following.
- EGR System Diagnosis:
Diagnosis of the EGR system should be performed if Powertrain Control Module (PCM) Diagnostic Trouble Codes (DTC) are set. See appropriate DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - 4.6L DEVILLE & SEVILLE article. - EGR Valve Pipe Cleaning & Checking For Leaks
Clean and check the EGR pipe from the exhaust manifold to the EGR valve, and the EGR pipe from the water pump crossover to the throttle body spacer. See EGR VALVE PIPE . - EGR Valve Cleaning
If the EGR system is operating correctly, the EGR valve can be removed, checked for deposits, cleaned, and re-installed. Use the procedure for this operation.- Remove the EGR valve from the engine. See EGR VALVE .
- While holding the EGR valve in your hand, use 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.
- While holding the EGR valve base in your hand, try to rotate the connector housing. Repeat for the coil housing. Replace any valve that exhibits looseness.
- 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 the deposits are such that pintle/base interface cannot be cleaned adequately to allow the 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, a wire brush or wheel, or by sand blasting. Cleaning by these methods is not recommended.
- Inspect the passage in the water crossover assembly for deposits. Remove all loose particles.
- Replace EGR valve on the engine using a new gasket.
- Cleaning EGR Passages In The Water Crossover Assembly
Remove the water crossover assembly. See WATER CROSSOVER ASSEMBLY under MISCELLANEOUS. Remove the 2 plugs and clean the passages with a wire brush. See Fig 1. Remove all loose particles. Re-install the water crossover assembly.