Sunday, May 11, 2014
How Does the Egr Valve Work
An exhaust gas recirculation valve is used to reduce the amount of emissions that an automobile puts into the atmosphere. The EGR valve was first used in the early 1970s and is now a standard feature used on most engines.
Operation
The EGR valve redirects a small amount of the exhaust that exits the cylinders through the exhaust valve into the intake manifold. Exhaust is pulled through a small tube via the intake vacuum. The EGR valve stays closed while the engine is cool or idling and opens when the engine is hot or running under a load.
Purpose
At high temperature, oxygen and nitrogen are combined to create nitrogen oxide (NOx). Among other problems, NOx causes respiratory complications and contributes to acid rain. The EGR valve introduces exhaust into the air intake to reduce the temperature of the combustion in the cylinder to prevent or reduce the creation of NOx.
Signs of Failure
When an EGR valve fails, the engine combustion temperature will increase causing performance problems for the automobile while also increasing NOx and hydrocarbon emissions. Engines will tend to knock or ping due to early detonation and the exhaust system may be damaged by the higher temperatures.
No comments:
Post a Comment