Regresar al GuidesWhat Does an EGR Valve Do?
The EGR valve is a part of your vehicle’s emissions system and works in conjunction with the exhaust and the engine. The valve recirculates the exhaust back into the combustion chamber through the air intake system along with the air that the engine usually uses to ignite the fuel and create the combustion. This reduces the amount of unburned fuel in the exhaust, which brings down harmful pollutants and increases the fuel economy.
Your vehicle’s EGR valve will either be electronic or manual. An electronic EGR valve has a solenoid that is operated by the car’s computer, which tells it when to open and close to let the right amount of emissions into the engine. A manual EGR valve opens using the engine vacuum to open and close at the correct time. The timing of the EGR is dependent on the speed and temperature of the engine in both the manual and electronic versions.
How Do You Know You Need to Replace an EGR Valve?
If your EGR Valve isn’t working properly, your engine won’t be running efficiently and the emissions will be more contaminated than they should be.
Depending on your car, this will manifest in a variety of different ways. Knowing some of the symptoms of a bad EGR valve can help you figure out if yours has gone bad so you can get it fixed and get your car working at its highest level.
Check Engine Light:
Perhaps the most common sign that your EGR valve has gone bad is a check engine light. While the check engine light can be frustrating because it is not very specific, your emissions system is usually a good place to start. If your EGR valve fails, the check engine light will come on almost immediately.
If your EGR valve gets stuck open or closed, the sensor will send a signal to your vehicle’s computer. This will get interpreted as a reason to trigger the check engine light. You can get a code scanner to read the computer, which will tell you what the issue is in the form of a specific code.
Poor Engine Performance:
If your EGR valve fails, you may notice a decrease in your engine’s performance. This is because your air-to-fuel ratio will be disrupted, which can cause a loss of power when you step on the gas pedal. Your engine needs the correct mixture of fuel and air to properly ignite and push the pistons in the cylinder.
Your vehicle is most likely tuned to account for the recirculated exhaust in the combustion chamber. If your EGR valve isn’t working and is either stuck open or closed, you will either be getting too much air or not enough in the engine. This can cause problems with acceleration or speed that you should be able to feel when driving.
Increased Emissions:
EGR valve problems will also greatly increase the number of harmful emissions your engine is putting out. The increased concentration of NOx means that your engine efficiency will be decreased and the exhaust will have a higher level of contaminants. This can be incredibly detrimental to the environment and the people in the cabin of your vehicle.
The increased emissions from your engine may also prevent you from passing an emissions test. The next time you are required to get your emissions tested, you won’t pass if your EGR valve is faulty. The technicians at the emissions testing facility should be able to give you the code that the car’s computer is putting out so you can properly diagnose the issue.
Rough Idle:
When the exhaust gas recirculation valve is stuck open or closed, your vehicle will idle roughly. This will feel a lot like a misfire or a loss of power when accelerating, both of which are symptoms of a bad fuel and air mixture in an internal combustion engine. The EGR valve regulates some of this mixture, so if it fails, you will notice rough idling.
How Much Does it Cost to Replace an EGR Valve?
Replacing an EGR valve is easy to do on your own and relatively inexpensive. The cost of the parts will most likely be between $190 and $270 depending on the make such as Ford or Toyota and the model of your vehicle, as well as if you have a traditional gas or diesel engine. If you are doing the replacement yourself, this will be the final cost for the job. However, if you are getting the valve changed at a shop, you can add $60 to $80 worth of labor to the final cost of the replacement.
What Causes an EGR Valve to Fail?
As with any other component on your engine, there are several reasons that your EGR valve might fail. Most manufacturers put the lifespan of the valve at around ten years. However, this will change depending on things like your driving habits and how many miles you put on your vehicle every year. Understanding some of the reasons your EGR valve may fail can help make it last as long as possible.
Bad Temperature Sensor:
A bad temperature sensor can wear out the EGR valve sooner than it should. When the temperature sensor goes bad, the operating temperature of the engine could go too high. This can cause all kinds of problems, including wearing out the valve prematurely.
Clogged EGR Exhaust Pipe:
In older vehicles, particulate matter, debris, and dust will end up in the engine no matter how well-maintained they are. This buildup of debris can collect in the EGR exhaust pipe and prevent the recycled exhaust from reaching the combustion chamber. This will disrupt the air and fuel mixture and cause all kinds of issues with the way the engine runs including engine knock and misfiring.
Stuck Valve:
Over time, the opening and closing mechanism on the EGR valve can wear out or become stuck. This will increase the number of contaminants in your vehicle’s emissions and cause the engine to run rough. When the valve gets stuck, it will have to be replaced if you want the engine to get back to its peak performance.
How to Replace a Faulty EGR Valve
If your EGR valve goes bad, you will have to replace it as soon as possible if you don’t want to cause serious damage to the engine. An EGR valve replacement is a relatively simple job that doesn’t require much in the way of time or materials. All you will need is a new valve, an adjustable wrench, and a ratchet and socket set to remove the old valve.
Park on a Flat Surface:
Before you begin working on your vehicle, park it on a flat surface. This will allow all the fluids to settle and ensure that nothing leaks out of the engine when you pull the valve apart. Make sure you let the engine cool down completely before beginning.
Find the EGR Valve:
Look in your vehicle’s owner’s manual to see where the EGR valve is located. For the most part, it will be on the side of the intake manifold but some vehicles have different designs. You can also look at the emissions sticker on the underside of the hood to see where your EGR valve is on the engine.
Remove the Exhaust Tube:
The valve will have a tube cnnected to it that feeds the exhaust that is to be recycled into it. Using your socket set, disconnect this tube and let it hang where it sits to make it easy to reconnect. Make sure you retain any bolts that come off the mechanism and remember where they are supposed to go.
Remove the Valve:
Once the exhaust tube is disconnected, you can then take the EGR valve off the intake manifold. Remove the bolts holding it on and discard the old valve. Hang on to any bolts that you take off since your new valve may or may not come with the right ones for your intake manifold.
Install the New EGR Valve:
Attach the new EGR valve and the gasket that comes with it and tighten the bolts to the recommended torque in the owner’s manual. Put the exhaust tube on the new valve and tighten those to the right torque. After the new valve is installed, you will have to drive the car long enough to allow the car’s computer to run checks and recognize the new valve. After the computer is reset, the check engine light should turn off.
What Does 'EGR' Stand For?
EGR stands for Exhaust Gas Recirculation, which is a process that allows the trace elements of fuel to be injected back into the engine. When your vehicle burns fuel, the nitrogen gas that is in the atmosphere is exposed to incredibly high temperatures. When this happens, nitrogen turns into harmful oxides of nitrogen.
Oxides of Nitrogen, also called NOx, can damage the human respiratory system and cause serious issues. These include things like breathing problems, allergy symptoms, and asthma attacks. The EGR system feeds NOx back into the engine, which reduces the amount that is expelled into the air we breathe.
When it comes to the most desirable qualities for new cars right now, fuel efficiency and eco-friendly features are at the top of the list. With a focus on hybrids and electric cars, automakers are working to make sure their vehicles are as environmentally sound as possible. This means including components that help bring down the levels of toxic emissions and keep prices down at the gas pump.
The EGR valve in your vehicle reduces fuel consumption and keeps the emissions coming out of the tailpipe as clean as possible. Knowing how the EGR valve works and how it keeps carbon deposits out of your exhaust will help you keep it in good working order so your vehicle can run cleanly and efficiently. By understanding the symptoms of a bad EGR valve and how to change one out, you can keep driving responsibly and safely.
Final Thoughts
The EGR valve allows your vehicle to run cleaner and more efficiently. If your valve goes bad, you could be looking at some serious issues that can cause damage to your engine and the environment. Knowing what the EGR valve does and what happens when it fails can help you recognize when there is a problem and get it fixed or replaced as soon as possible.
