Exhaust Gas Recirculation: Service and Repair
EGR Control Valve Cleaning
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.
Caution: Wear approved eye protection for this cleaning procedure, to avoid possible injury to the eyes.
Clean the control valve as follows:
1. Disconnect vacuum hose from EGR valve, then remove EGR valve-to-manifold retaining bolts, and the control valve.
2. With a wire wheel, remove the exhaust deposits from the mounting surface and around the valve.
3. 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.
4. 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.
5. Check for wear of the poppet valve or stem, if any is noticed the control valve should be replaced.
6. Install new gasket, then install the control valve.
7. Reconnect the vacuum hose to the control valve.