How Can A Faulty EGR Valve Damage Your Car?

EGR valve, is an important device that reduces the car’s nitrogen oxide emission. A faulty EGR valve can damage your engine in many ways including misfiring and a damaged turbocharger. There are several symptoms of a failing EGR valve like reduced engine performance, increased fuel consumption, the smell of fuel in the exhaust, and a delay in engine start.

Driving a car sure has made our travelling life easier than in ancient times, hasn’t it?

But is it more environmentally friendly than before? Of course, the answer is no, although we can control how much cars affect the environment using exhaust gas recirculation EGR.

It’s not possible when our EGR breaks down. Not only does a faulty EGR hamper our environment, but it also damages our cars. What happens when EGR valve goes bad? How can a faulty EGR valve damage your car? How can you fix it? What are the symptoms of a damaged EGR valve?

To figure out all of the answers to these questions, you need to stick with us till the very end. So let’s unravel the truth about the EGR valve together, shall we?

What is an EGR valve?

An EGR (Exhaust Gas Recirculation) valve is a device that recirculates the exhaust gasses in the engine. It takes exhaust gasses from the engine outlet and reinjects them in the engine air inlet. It’s monitored by an ECU, also known as Engine Control Unit.

An EGR device helps us to decrease the pollution caused by our cars and increase our car fuel economy. The exhaust gases in our cars include Nitrogen oxide and the EGR helps to reduce the amount of it.

There are a few names for the EGR valve in the mechanical engineering department such as a wastegate, a boost controller, a bypass valve and a turbo timer, etc.

What Are The Symptoms of a Bad EGR Valve?

A good car owner should know that their car’s EGR is failing by the symptoms of a bad EGR valve but this is not that easy. Symptoms of failing EGR valves are difficult to monitor and need special dedicated & continuous monitoring of several parameters.

Let’s discuss the faulty EGR valve symptoms.

How A Faulty EGR Valve Damage Your Car Infographic

A great delay on your engine

When your engine has a delay longer than 5 seconds or more when you start your vehicle is a symptom that your EGR valve is faulty. What happens here is that the EGR valve repeatedly opens and shuts and the flow of EGR gases goes towards the manifold.

Car poor performance

Poor performance by car engines is one of the common EGR valve failure symptoms. When the EGR valve is open or closed permanently, you will notice that your car engine is performing poorly in terms of delivering power. The EGR valve’s dysfunction can cause this type of problem.

Fuel consumption getting increased

When your car has a failed EGR valve with the valve being continuously open, you might observe that the fuel consumption has rapidly increased.

This is mainly due to two reasons, first is that there is less oxygen in the air-fuel mixture due to more recirculating gasses, this results in more fuel consumed for delivering the required power.

Second, the high air intake force engine to put in more fuel to maintain a good air-fuel ratio.

You would be able to smell fuel

As there is a continuous flow of EGR gases into the manifold, so, when the EGR valve is always open, you can smell the fuel. This same as above where less oxygen results in the incomplete burning of fuel.

With more fuel in the exhaust and EGR being continuously open you can smell fuel while being in the car. It’s also because in low temperatures, not all of the fuel burns, so the hydrocarbon gases discharged from the engine elaborate the smell of fuel in the atmosphere.

Alright, now you know the most common bad EGR valve symptoms. Let’s see what damage a faulty EGR can cause.

What Damage Can a Faulty EGR Valve Cause?

A defective EGR valve is not only harmful to the atmosphere, but it also harms our body and the car. So we need to learn about the damages a faulty EGR valve is causing.

Damaging the Turbocharger

You may wonder, can a faulty EGR valve damage turbo? The answer is yes. An EGR valve that is defective would most likely build up carbon and rapid soot because of the constant flow or opening and closing of the EGR in the engine.

The EGR gases contain a massive amount of carbon, and when the valve is opened for a longer period, the carbon starts to build up. This scenario causes damage to your turbocharger and other valves.

Causing a misfire

So, can a bad EGR valve cause a misfire? Yes, a misfire can be caused by the congested passages inside the car’s engine air inlet valve. It might terminate your car’s power output.

The oil vapours in the engine would escalate carbon imbalance in the EGR valve. It will trigger the frozen valve.

A bad ECU reduces the amount of fuel insertion and that leads to the reduced output of your car’s engine. All of these will cause a misfire while driving the car.

Damaging the EGR solenoid

The EGR solenoid can be considered one of the most crucial parts of the EGR device itself. It would be the EGR valve itself that might damage your vehicle’s EGR solenoid.

A bad EGR valve results in a permanently opened EGR solenoid valve. One of the most common bad EGR solenoid symptoms is that a damaged EGR solenoid will cause performance problems in the engine and the entire car.

What Causes EGR Valve Failure?

Knowing what causes an EGR valve to go bad will help you relate to your situation and find the reason from where the problem is coming.

  • Over time, there could be a build-up deposit in your EGR valve which can cause the valve to fail.
  • Poor management of your car engine also is a reason behind a failed EGR valve.
  • If the engine cooling system of your vehicle is damaged, chances are the EGR valve will fail.
  • When you have several numbers of short-distance drives, there could be a formation of oil and water emulsion which eventually causes an EGR valve to fail.
  • If the vehicle engine ventilation doesn’t function properly, it can also result in a failed EGR valve.

How to Fix A Faulty EGR Valve

When you notice the faulty EGR symptoms, you can either take your vehicle to a professional mechanic or you can replace the faulty EGR yourself. Know that the replacement cost of a faulty EGR can be around $380 which includes the EGR and labor cost. So, if you’d like to run a DIY project, you can save the labour cost.

Here’s how you can replace a faulty EGR valve at home.

  • Find where the EGR valve is in your engine bay.
  • Detach the vacuum lines and find the bolts that hold the valve in place.
  • Once you find the volts, unscrew them and remove them.
  • Now, it’s time to install the new EGR. You can install it using the same bolts.
  • Once done, reconnect the vacuum lines and test drive your vehicle and clear error codes.

How to Prevent EGR Valve Failure

Fortunately, there are some ways you can follow to prevent the failure of the EGR valve.

  • Make sure the EGR valve stays clean always including the inside of the valve. You can use a carburettor cleaner which softens any stuck residue and helps you clean the inside of the valve effectively.
  • Try to use EGR/DPF fuel additives to drive your vehicle.
  • Get your temperature sensors examined occasionally and replace them when needed.

FAQs on a faulty EGR valve

1. Can bad EGR valve damage the engine?

Yes, it can. A faulty EGR solenoid, which is mostly caused by a faulty EGR valve, will muster carbon in the consumption manifold and freeze up the engine’s EGR solenoid. It will cause some performance issues for the engine in your vehicle.

2. Can you drive with a faulty EGR?

No, you shouldn’t drive with a faulty EGR. The valve will be constantly opened and the EGR gases will insert into the combustion area to cool the chamber down. It will decrease oxygen insertion. When your EGR valve is at fault, the EGR gases’ emission will escalate and it will cause engine overheating.

3. What will happen if the EGR valve gets stuck?

Actually, it is the EGR solenoid that will get stuck. But the EGR valve will cause that sort of scenario. If an EGR solenoid gets stuck either opened or closed, the flow of EGR gases will get interrupted. It will cause performance issues in your engine.

Final Thoughts

The EGR device is a crucial part of both your vehicle and the environment. As you’re aware of the fact that EGR gases consist of a lot of greenhouse gases, we need to control the emission of those gases to protect the atmosphere.

And if you want to repair your vehicle’s faulty EGR valve, you can go to any automobile repair shop like Midas International which can be found in any nation in South-East Asia.

Now, you know how can a faulty EGR valve damage your car, so you should be on guard more than ever.

Leave a Comment

Written By

Photo of author

William Baldwin

This Is William Baldwin, The Founder & Managing Editor of this website. Me and my team share automotive tips, tricks, and news

Fact Checked And Mechanically Reviewed By


Talha Atta

Talha Atta, a Mechanical Engineer and experienced technical content writer and editor at with a passion for the automotive industry.