Operation CHARM: Car repair manuals for everyone.

EGR System Cleaning


EGR VALVE

CAUTION: Do not wash any EGR valve in solvents or degreaser, as permanent damage may result, also, sand blasting of the valve is not recommended, since this can affect the operation of the valve.

Wear approved eye protection for this cleaning procedure, to avoid possible injury to the eyes.


1. Disconnect vacuum hose(s) from EGR valve. Remove EGR valve-to-manifold retaining bolts, and the control valve.
2. Carefully plug the ports into the manifold with a clean shop towel or other suitable cloth. This will keep debris from falling in.
3. With a wire wheel, remove the exhaust deposits from the mounting surface and around the valve.
4. Open the control valve with an external vacuum source, and check for excessive buildup of carbon deposits. Anything more than a thin film is excessive.
5. Using a suitable sharp edged tool, scrape the carbon deposits from the control valve poppet. Do not scratch the valve seat or dislodge the poppet from its stem.
6. Check for wear of the poppet valve or stem, if any is noticed the control valve should be replaced.
7. Install new gasket, then install the control valve.
8. Reconnect the vacuum hose(s) to the control valve.




EGR PASSAGES

NOTE: When cleaning EGR passages, care should be taken to ensure that all loose particles are completely removed to prevent them from clogging the EGR valve.


1. Disconnect vacuum hose(s) from EGR valve. Remove EGR valve-to-manifold retaining bolts, and the control valve.
2. Scrape carbon deposits from the EGR manifold port using a suitable sharp edged tool. Use a wire wheel and brush to remove the deposits from the valve mounting surfaces.
3. Use a vacuum cleaner to remove any loose particles from EGR manifold ports and control passages.
4. Install EGR control valve, using new gasket.
5. Reconnect EGR vacuum hose.

Refer to MAINTENANCE SCHEDULES for service intervals.