How to Replace a Buick's EGR Valve

by Chris Stevenson
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exhaust pipe image by A74.FR Ben Fontaine from

The EGR (exhaust gas recirculation) valve on your Buick serves a very important task in your vehicle's emission control system. It sends a large portion of the exhaust gases back into the intake manifold for an additional burn. This performs a type of "after-burn," which ensures that all of the fuel that enters the intake systems gets completely burned in the combustion process. The EGR valve also cools the emissions for a more even burn. Defective EGR valves that become plugged or stuck can make the engine run rough and hurt performance and fuel economy.

Step 1

Shift the vehicle into park or neutral and set the emergency brake. Raise the hood. Disconnect the negative battery cable with a socket and wrench. Locate the EGR valve on your Buick near the intake manifold. It looks like a cylindrical device, about half the size of a soda can, with tubes underneath it and a sensor wire on top. If you have a Buick engine equipped with a plastic plenum on top of the manifold, use a socket and wrench to loosen and remove the plenum bolts. Set the plenum aside.

Step 2

Locate the sending unit wire on top of the EGR valve. Use a flat head screwdriver to pry the small retaining clip back while you pull the small jack out of its connector. Spray the inside of the jack with electrical contact cleaner. Locate the two (sometimes three) bolts that hold the EGR valve to the adaptor plate. Use a socket, extension and ratchet to loosen and remove the bolts. Pull the EGR valve off the adapter plate.

Step 3

Use a gasket scraper to remove the old gasket material from the adapter plate. Clean the surface with carburetor cleaner and a rag. Clean out the inside surface of the adapter hole with a cotton swab soaked in carburetor cleaner. Clean as far down inside the valve body as you can.

Step 4

Install the new EGR valve gasket over the adapter plate and align the new EGR valve over its mating surface. Start the mounting bolts in by hand as far as you can. Refer to your owner's repair manual for the proper torque for the EGR valve and tighten the bolts with the torque wrench. Use an extension on the end of the ratchet wrench if you have clearance problems.

Step 5

Reconnect the sending unit wire to its jack -- pry the plastic retaining clip up and push down on the jack, snapping it into place. Reconnect the negative battery cable with the socket and wrench. Start the engine. Look for a "Check Engine" light on the dashboard. If you see one, shut the engine off and let it sit for several minutes. Restart the engine. The "Check Engine" light should reset and disappear.

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