Your vehicle’s exhaust gas recirculation (EGR) system is in charge of reducing the nitrogen oxides (NOx) produced in your engine by controlling both the amount of oxygen in the cylinders and the combustion temperature. The EGR valve is a part of the system, situated on the exhaust manifold side of the engine to help control the gases and temperatures in the chambers.
If you notice that your engine is acting sluggish or if you hear a pinging sound coming from the engine bay, something is likely wrong.If the pinging is from the EGR, this means it’s not working correctly. The pinging could come from the EGR valve itself, passages, EGR valve control, or so on. You should have this diagnosed because it could be so many different things, and EGR valves don’t all operate the same way.
An onboard diagnostic (OBD) tool can help you figure out if an oxygen sensor or the EGR is to blame. If it’s the latter, it might be time to replace the EGR valve. Alternatively though, an EGR valve can also be cleaned.
You might find that the problems in your EGR system go away after cleaning the EGR valve. \ It’s important to note that the EGR valve doesn’t have a replacement interval, and it only needs to be replaced if it fails. That being said, you can still extend the life of the EGR valve by cleaning the parts around it.
Generally the EGR valve itself doesn’t need cleaning. If anything needs cleaning, it’s typically the EGR passages from the valve to the intake manifold, which can clog up. Follow these steps to use an EGR valve cleaner:
To start, you’ll need to pick up a bottle of EGR valve cleaner, newspaper or a cloth, and a pipe-cleaning brush. You can also use carburetor cleaner as an alternative. Prepare your safety gear as well. The cleaner is acidic and the chance of backsplash is high enough to necessitate some safety glasses and a set of acid-resistant gloves. A filter mask wouldn’t be amiss either.
Make sure to park your vehicle on an even surface with the emergency brake engaged. Disconnect the negative terminal of the battery before proceeding. After that, you’ll need to find the EGR valve. It’s typically attached or adjacent to the intake manifold, connected to a tube that runs to the exhaust manifold.
Remove the vacuum hoses and electrical connectors before proceeding. You might need to use an adjustable wrench, a ratchet, or a socket to separate any brackets attached to the valve. Once these are all removed, you can pull the EGR valve from the engine block and set it on some newspaper or a cloth.
There’ll be a good amount of carbon buildup on the inside of a dirty EGR valve. Aim the EGR valve cleaner nozzle at the buildup and spray. You can use the pipe-cleaning brush to remove the loosened debris. Repeat this until any stubborn carbon has been removed. You can even leave the solution to soak a bit in the valve to penetrate any extra stubborn carbon layers. You can reinstall the EGR valve once it’s completely dry.
You might not notice it, but the NOx gases from your vehicle will lessen once your dirty EGR valve is finally clean. While the EGR valve being dirty is the least common cause of EGR system failure, keeping the EGR in good shape still helps your engine by increasing its performance and longevity. On the other hand, using an unclean EGR valve can damage both your vehicle and the environment.
When you have a faulty or clogged EGR valve, you might also notice the engine vibrating, a rough idle, and difficulty starting the car. Your fuel economy might also tank, and the vehicle might overheat. Poor acceleration and the scent of unburned gas are also common symptoms of a bad EGR valve. You’ll also likely fail your next smog test if you continue to ignore the valve’s need for maintenance. Using EGR valve cleaner to keep your valve in tip-top condition will help you avoid all these inconvenient symptoms.
There are two main types of EGR systems. One is the internal exhaust gas recirculation (iEGR) and the other is the external exhaust gas recirculation (EGR). In both systems, the exhaust gases are returned to the intake manifold to be recirculated, reducing NOx.
Technically, if you have an EGR system, it is external to the engine, has a valve, controller of sort (whether it be vacuum or, if it is electronic, then it is the PCM), and then the passages that the exhaust gas passes through and into the intake manifold to be recirculated into the combustion chamber.
An iEGR system is just the computer’s way of reducing combustion temperatures by opening and closing valves at different times. The external EGR system is more efficient and more commonly used by vehicle manufacturers.
Technically, if you have an EGR system, it is external to the engine, has a valve, controller of sort (whether it be vacuum or, if it is electronic, then it is the PCM), and then the passages that the exhaust gas passes through and into the intake manifold to be recirculated into the combustion chamber.
An iEGR system is just the computer’s way of reducing combustion temperatures by opening and closing valves at different times.
–Anthony Harlin, ASE Certified Master Automobile Technician
Because the EGR system is more common, it’s important to know how to clean the EGR valve as shown in this article.
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