12736936
EGR Valve · General Motors
Exhaust gas recirculation valve: controlling the EGR rate, part-number assignment and replacement checks
The EGR valve meters the proportion of already-burnt exhaust gas admixed into the intake tract, lowering peak combustion temperature and nitrogen oxide formation in the cylinder. Electropneumatically or electric-motor-actuated valves open and close a valve disc or throttle plate in a bypass between the exhaust manifold and the intake path, controlled by the engine control unit according to load point, engine speed and coolant temperature. On cooled recirculation, the valve sits in series with the EGR cooler.
The part number is tied to the type of actuation, to the diameter of the valve disc or throttle plate, and to the recirculation-rate maps tuned in the engine control unit for the engine family and emission stage. With every model year and emission stage, the connection geometry at the manifold and the position of the associated position sensor change. The assignment of part numbers to engines and machines on this page comes from official certification documentation issued by the US Environmental Protection Agency.
Soot deposits and coked oil-mist residues stick the valve disc and its guide, leaving the valve stuck in an intermediate position, causing either a rough idle with power loss or excessive nitrogen oxide formation. A worn valve shaft or a faulty position sensor produces inconsistent position feedback; a leaking valve seat is often recognisable from a rough idle and fluctuating boost pressure.
Replacement is governed by the part number, since flange pattern, actuation type and stored maps can differ between valves that otherwise look identical. Checks should cover the sealing faces at the manifold and intake flanges, the condition of the connector, and the free movement of the valve shaft before fitting. After replacement, the control software often requires a base setting or a learning drive for the position sensor. Pricing and availability are not part of this page.
Excludes price and availability — those come from the supplier.