Chevrolet 1997169 Solenoid Asm,EGR Control Valve Relay

You can Select Your Vehicle to check if 1997169 fits your vehicle.

If the thermal vacuum switch is defective, it should be replaced.

This system is used to reduce oxides of nitrogen (NOx) emitted from the exhaust. It recirculates a small amount of exhaust gas in the combustion cycle to reduce peak temperatures and the formation of NOx. The EGR valve, located on the intake manifold, is the heart of the system and should be inspected occasionally. Two types of EGR valves are used: negative backpressure and positive backpressure. The system does not operate at idle or during deceleration and is regulated by a thermal vacuum switch. Common engine problems associated with the EGR system include rough idling, stalling, and rough engine performance. To check the EGR valve, push upwards on the diaphragm plate and ensure it moves freely. Start the engine and manually depress the diaphragm to check for changes in engine speed. Check for vacuum at the EGR valve and inspect for disconnections or blockages in the vacuum lines. The thermal vacuum switch regulates EGR valve operation based on engine temperature and can be tested with a vacuum gauge. If the switch is defective, it should be replaced. To replace the EGR valve, disconnect the vacuum hose, remove the nuts or bolts securing the valve, clean the mounting surfaces, and install the new valve with a new gasket. To replace the thermal vacuum switch, drain the engine coolant, disconnect the vacuum hoses, remove the switch using a wrench, apply thread sealer to the threads, and install the new switch.

When removing and reinstalling the EGR valve or thermal vacuum switch, it is important to follow the necessary steps. Additionally, a new gasket and thread sealer should be used during reinstallation.

The functioning of the EGR valve can be checked by manually depressing the EGR diaphragm. If the engine loses speed or stalls, it indicates that the valve is working correctly.

With the engine cold to prevent burns, you can reach under the EGR valve and manually push on the diaphragm. Using moderate pressure, you should be able to press the diaphragm up and down within the housing.

If you are unsure about the quality of the valve, you can compare the free movement of your EGR valve with a new valve.

The ECM controlled solenoid is used to maintain finer control of EGR flow.

The Exhaust Gas Recirculation (EGR) system is used to reduce NOx emissions by lowering combustion temperature. The system includes the EGR valve, which is mounted on the intake manifold and recirculates small amounts of exhaust gas back into the combustion chamber. The EGR valve is opened by manifold vacuum and is usually open during warm engine operation and when the engine is running above idle speed. The amount of gas recirculated is controlled by variations in vacuum and exhaust backpressure. The valve used on this engine is a negative backpressure valve, which varies the exhaust gas flow based on manifold vacuum and exhaust backpressure. The diaphragm on the valve has an internal vacuum bleed hole that is held closed by a small spring when there is no exhaust backpressure. Engine vacuum opens the EGR valve against the pressure of a large spring. An ECM controlled solenoid is used in the vacuum line to maintain finer control of EGR flow. The ECM uses information from various sensors to regulate the vacuum solenoid. Too much EGR flow can cause rough running, stalling, or surging, while too little or no EGR flow can result in spark knock, engine overheating, and emission test failure. To check the EGR system, a physical inspection of hoses and connections should be done, and the EGR valve should be checked for proper operation and vacuum. The EGR solenoid should also be checked for movement and vacuum. If any components are faulty, they should be replaced. Cleaning of the EGR valve and passages may also be necessary.