How to check an EGR valve?
The EGR valve, which stands for Exhaust Gas Recirculation, is an automotive component that reduces the emission of toxic gases into the air, thereby reducing environmental pollution. This ingenious device is a type of valve that redirects the combustion gases emitted by the engine to the fuel injection system, where they are automatically burned.
You've noticed certain signs on your vehicle's valve and you're not sure if it's working properly. Read this article and you'll know exactly how to test an EGR valve.
What's the EGR valve for?
The EGR valve is found on all newer diesel vehicles, as well as some gasoline vehicles. Its purpose is to reduce your vehicle's exhaust emissions. The EGR valve, which stands for Exhaust Gas Recirculation, was introduced in response to new European pollution standards.
An EGR valve reduces nitrogen oxide (NOx) emissions. An EGR valve works as follows:
- Exhaust gases are diverted to the intake manifold;
- The gases are then burned a second time by injection and cooled;
- Oxygen levels in the cylinders are reduced to lower combustion temperatures.
Once cooled, the exhaust gases emit far less nitrogen oxides. However, the EGR valve operates only at low engine speeds, when emissions are highest. It's a valve that opens and closes, so it closes when you rev up.
How do I test my vehicle's EGR valve?
Like many parts, the EGR valve is subject to wear and is particularly susceptible to soot buildup. This soot clogs the EGR valve and causes a number of problems, including loss of engine power, increased emissions, and black smoke in the exhaust. So if you notice one or more of these symptoms, you need to check your EGR valve as soon as possible.
Step 1: Purchase an EGR Valve Tester
To test your EGR valve, you'll need a device that allows you to check its operation. To test your EGR valve, you'll need a tester. This tool can be purchased at any auto parts or accessories store. Once you've purchased this tool, you'll also need to provide the wiring diagram for the EGR valve.
Step 2: Connect the tester to the valve terminals
Refer to the EGR valve wiring diagram to determine the location of the terminals. They are not all identical in terms of electrical pins. So, after connecting the ground wire to the pin shown on the diagram, connect the positive wire to the pin shown on the diagram. This device will send an electrical impulse to activate the EGR valve.
The function of the EGR valve is to reduce the vehicle's pollutant emissions by re-injecting exhaust gases into the intake system. These gases are burned a second time and cooled, making them less harmful.
Step 3: Perform the EGR Valve Test
Next, turn on the tester using a potentiometer. Increase the speed because the valve needs to work. If your EGR valve is in good condition, it should work. If not, the EGR valve is defective.
In any case, if you test your valve and it works easily, don't think about replacing it, think about cleaning it. Be aware that your valve is faulty if it shows signs such as the engine light or exhaust warning light coming on, the engine going into an emergency program, a problem starting and limited engine power, the vehicle moving jerkily while driving, etc. In any of these cases, your valve needs to be repaired or replaced.
