What does the EGR valve do in an engine?
The EGR valve, or Exhaust Gas Recirculation valve, is a vacuum controlled valve which allows a specific amount of your exhaust back into the intake manifold. This exhaust mixes with the intake air and actually cools the combustion process. Cooler is always better inside your engine.
Why is my EGR valve stuck at idle?
EGR Valve The exhaust gas recirculation (EGR) valve allows a certain amount of exhaust gases into the intake manifold to help lower engine temperature and harmful emissions. When the valve fails, it may get stuck close or open, or even leak. It is when the valve remains open when engine idle suffers.
Can a bad EGR valve fail an emissions test?
In fact, if you have a faulty EGR valve, your vehicle will most likely fail an emissions test. You can often notice a slightly more amount of smoke when the EGR valve is bad, but most often it is not very common.
What are the pros and cons of EGR?
Cons of an EGR Valve. When the EGR valve goes bad, it must be replaced. Unlike some emissions control devices that can go bad without affecting the drivability of the car or truck, a bad EGR valve can really affect the engine’s performance or even cause it to stop running altogether.
Why is the EGR valve open at part throttle?
At part throttle, there is a vacuum in the intake manifold. Also the exhaust gas is at positve pressure. So when the EGR valve opens, exhaust gas is easily drawn into the intake manifold. Running EGR allows you to run more timing at light cruise loading.
What are the symptoms of a bad EGR valve?
A rough idle upon starting the engine (that is, when the engine is cold) and sometimes at a stop light or while looking for a spot in a parking lot (that is, at low engine speeds in a warmed-up engine). Stalling when the engine idles. Increase in fuel consumption.
What happens when you remove the EGR system?
If the EGR is functioning then all of the .575 liter of space will not be filled with the maximum amount of the air and fuel mixture as possible. There will still be a small amount of space occupied by the spent exhaust gases in the engine.
Where are the EGR Jets in the intake manifold?
A more radical design, implemented in a few models, was the replacement of the valve with EGR jets at the bottom of the intake manifold. Some newer high-efficiency engines, for example those with variable valve timing (VVT), don’t even use an EGR system. If playback doesn’t begin shortly, try restarting your device.