How to Clean an EGR Valve on a Geo Metroby Dan Ferrell
The EGR valve on your GEO Metro lets exhaust gases from the cylinder head exhaust port into the intake manifold. This not only rids the engine from some harmful emissions but also helps reduce high temperatures in the combustion chambers. However, valve passages between the exhaust and intake ports, and inside the EGR valve, fill with carbon deposits after months of service, affecting engine performance. The only way to fix the problem is to take the valve off the engine and clean those passages.
Open the hood and locate the EGR valve. The component is located around the top of the engine. It resembles a metal, flattened mushroom between 2 and 3 inches in diameter.
Detach the vacuum hose from the top of the EGR valve with your hand.
Remove the one or two valve mounting bolts, depending on your particular model, using a ratchet, ratchet extension and socket. Discard the valve gasket.
Clean the valve bottom passage from carbon deposits using a scratch awl. Be careful no to damage the valve-sealing surface to avoid exhaust gas leaks. Tap the bottom of the valve lightly on a hard surface to get rid of loose carbon inside the valve.
Clean the exhaust and intake port passages using the scratch awl. Also, be careful not to damage the sealing surfaces.
Scratch any gasket material off the exhaust, intake and valve sealing surfaces using a plastic scraper, if necessary.
Set the EGR valve in place on the engine along with a new gasket. Start the mounting bolt or bolts by hand to avoid damage to the threads.
Tighten the EGR valve mounting bolts with the ratchet, ratchet extension and socket but do not over tighten them.
Attach the vacuum hose to the top of the EGR valve.
- If you need more help locating specific components on your GEO Metro, consult your vehicle service manual. You may buy one at most auto parts stores or consult a manual for free at your local public library.
- When working on the EGR valve and related components in your GEO Metro, be aware that it only takes a few minutes for the exhaust system and other parts to reach very high temperatures. Use caution to avoid skin burns and other injuries.
Items you will need
- Ratchet and socket
- Ratchet extension
- Scratch owl
- Plastic scraper
- New EGR valve gasket
- Photo courtesy of IFCAR at Wikipedia.org.