What Are the Symptoms of a Bad EGR Valve?

symptoms of a bad EGR valve

The EGR valve is the abbreviation for Engine Gas Recirculation valve. You can mostly find this component in internal combustion engines. Internal combustion engines are one of the standard types out there, typically used for automotive and aviation.

Thus, almost every car has the EGR valve. It’s responsible for the reduction of nitrogen oxide emissions, which is really what engine gas recirculation is all about. Today will try to understand EGR valves more by knowing symptoms of a bad EGR valve. Stay tuned!

Understanding the EGR valve

Before understanding what an EGR valve is, it’s important to know what engine gas recirculation is all about. That’s because the former is a component that can break, while the other is a process.

In the introduction, we gave a brief overview of what this process is. Again, it mainly focuses on the reduction of nitrogen oxide emissions. That is usually the case for air-fuel combustion engines like petrol and diesel.

understanding the EGR valve

So, why is there a need to reduce nitrogen oxide? The answer is to reduce air pollution. Along with carbon dioxide, nitrogen oxide is terrible for the environment. After all, it’s one of the most dangerous gases that contribute to global warming.

This gas is a simple mixture of nitrogen and oxygen. It’s the gas that forms upon the combustion of the air-fuel mixture in the combustion chamber of the engine. With that said, it’s a toxic waste that our vehicles produce.

So, to combat this problem, vehicle manufacturers have installed a system where a large quantity of nitrogen oxide will recirculate. By recirculation, this means that it does not emit the toxic gas outside. Instead, it will be recycled back into the engine for combustion purposes.

Thus, emerged the term engine gas recirculation or EGR. To expound, EGR takes a portion of exhaust gas, brings it back in the engine, and uses it for temperature control. So what exactly do we mean by temperature control?

The recycled nitrogen oxide will dilute the oxygen that your car takes in outside. That weakens its combustibility by a few margin, just enough to bring down high temperatures in the cylinder. It’s mainly replacing combustible matter with a non-combustible one.

The Function of an EGR valve

what does an EGR valve do

Source: http://vandogtraveller.com/seaside-mechanics-day-fixing-stuff/

So now we can finally answer the question “What does an EGR valve do?”. EGR valves are responsible for efficiently transferring the nitrogen oxide back into the engine. It does so by taking in the exhaust gas in portions that it controls. Afterwards, the EGR valve shifts it towards the intake manifold.

Hence, the EGR valve is a traffic enforcer in your engine that directs the flow of the nitrogen oxide. Like the other valves present in your engine, the EGR valve opens and closes depending on the time. For the EGR valve, it becomes active as soon as you start the engine. However, it may be engaged, but it idles while closed.

The only time that the EGR valve will open is when the temperatures are rising inside. The increase in engine temperature means that it’s approaching the combustion stage. After this stage, it will soon go under the exhaust stage, which the EGR valve participates. The lid closes every time you come to a stop to block of exhaust gas.

Symptoms of a bad EGR valve

Now that the EGR valve and the process of it are made clear, we can now discuss the symptoms of it. Since it functions as a valve, these symptoms are quite similar to other valves such as the exhaust and intake valves.

  • Rough idling

Rough idling in your car happens for many reasons. But often people neglect the big problem with this issue. That’s because rough idles are harmless if you think about it. There are no significant issues with acceleration and braking.

However, it’s usually a symptom of something bigger. For this instance, it can mean that the engine is cold. Why is it cold? Well, this is a result of a failing EGR valve. As we explained earlier, intake of exhaust gas causes the engine to cool down a bit.

If the EGR valve is open for long periods of time than the usual, this means more exhaust gas will enter. Thus, it causes the engine to cool down significantly to a fault.

  • Increased fuel consumption

increased fuel consumption

Source: http://wonderfulengineering.com/increase-your-cars-fuel-mileage-using-these-simple-steps/

Regarding the first symptom, increased fuel consumption ties to it. That’s because an oft-open EGR valve will disrupt fuel efficiency. Because there’s an excess of nitrogen oxide present, there are fuel portions left unburned.

Unburned fuel does not only mean your engine would take in newer fuel. It would also say that it would emit a bad odour and toxic emissions. After all, our vehicles were never designed to “not burn” fuel.

  • Noisy engine with firecracker detonations

This problem along with the one below will talk about an EGR valve that is oft-closed. A closed EGR valve will cause the opposite effect from the previous symptoms. This time, it would increase temperatures and produce faulty emissions.

A noisy engine with a lot of backfiring and detonations can mean a lot of things. However, increased engine temperature along with these loud explosions implies that there’s a lot of combustible matter inside. Of course, this is supplemented by a failing emissions test since the valve is shut and not working.

Summing it Up

When taking these symptoms of a bad EGR valve into account, always remember that it’s a matter of two cases. One is when it’s closed, and second if it’s open. Either of the two would create a problem that is easy to spot. And that’s failing the emissions test.

Finding out if your valve is malfunctioning is possible by inspecting it inside the engine. You can do this yourself or hire a mechanic to do it. Regardless, pay attention and always maintain your engine. By doing so, you’ll reduce the chances of having trouble with your vehicle’s performance.

With that said, good luck and don’t forget to share your thoughts below! Many thanks!

Steven K. Galloway