Everything You Need to Know about EGR Valves

13 September 2021
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Everything You Need to Know about EGR Valves
Have you ever heard somebody talking about EGR valves, but you don’t know what they are? Perhaps you have been experiencing some performance issues with your car, and by searching for those symptoms you have heard it suggested that the problem could be related to your EGR valve. Whatever the case, if you’re reading this article then you must have a reason – so this article will tell you everything you need to know about EGR valves. 

Key Insights

What is an EGR valve?

What does an EGR valve do?

How does an EGR valve work?

An exhaust gas recirculation (EGR) valve is an engine component which reduces NOx emissions, reduces fuel consumption and increases engine efficiency. It does this by regulating the specific quantity of exhaust gas which is allowed to re-enter the intake system. By changing the chemical composition of the air entering the engine, with less oxygen, the diluted mixture burns slower. This leads to lower temperatures in the combustion chamber (even by up to almost 150°C) which reduces NOx production for a cleaner and more efficient exhaust.  


How to clean an EGR valve?

How to clean an EGR valve without removing it?

How often should you clean your EGR valve?

How long does it take to clean an EGR valve?

Firstly, it is difficult to say how long the cleaning process will take, as this will depend on the individual’s car knowledge as well as the state of your valve and whether or not you remove it. However, to give a ballpark figure, you might expect this to take you anywhere from 30 minutes to two hours. Car manufacturers recommend that you clean your EGR valve every 50,000 miles or so. To clean your EGR valve, you will first want to ensure that your car is on a flat surface with the engine switched off and in park with all the brakes engaged. To begin with, find your car’s EGR valve and remove it along with any other parts that are in the way. Unplug any electrical connectors that are attached to the valve and unscrew the mounting bolts.  For the cleaning, make sure you are wearing acid-resistant gloves in addition to safety goggles. Spray an EGR valve cleaner onto the carbon deposits and remove the buildup with a pipe cleaning brush and scraper. Repeat this step until all carbon deposits have been removed and finish by wiping down with a clean cloth, before replacing the EGR valve.  If all of that sounds too difficult, you can attempt to clean the valve without removing it by spraying an EGR valve cleaner into it periodically, while someone keeps the RPMs between 1500-2000. However, this is likely to be less effective.

Does TerraClean clean an EGR valve?

Can you clean an EGR valve with WD-40?

Will Redex clean an EGR valve?

Can you clean an EGR valve with brake cleaner?

Yes, TerraClean is designed to clean several components including EGR valves. Some people say that they have successfully cleaned their EGR valve with WD-40, whilst others do not recommend it. Fuel additives such as Redex are not equipped to clean EGR valves, as it is exhaust gases that are passing through the valve. Although some people do attempt to clean their EGR valve with brake cleaner, generally this is not recommended and may pose safety issues. There are EGR valve cleaners made specifically for that purpose which are much safer and more effective than using a brake cleaner.   


How much does it cost to get an EGR valve cleaned?

Should I clean my EGR valve or replace it?

How much is an EGR valve?

Where to buy an EGR valve?

EGR valve cleaning prices will vary greatly depending on which company does it and how thorough they are (if they remove it for example). In many cases, if you are going to remove your EGR valve to clean it – or have a mechanic do this for you – it might be more appropriate to replace the part instead. Depending on your car model, an EGR valve can cost anywhere between £90 and £350. The best way to find accurate pricing for your model is to use a site like Autofixa, where you can buy a manufacturer-approved EGR valve specifically designed to fit your car.   


What damage can a faulty EGR valve cause?

What are the symptoms of a faulty EGR valve?

A faulty EGR valve can cause problems for your vehicle in addition to adverse effects on your health. These problems are numerous and range from reductions in acceleration and power through to increases in vehicle emissions. Below is a list of symptoms that a faulty EGR valve can show. Bear in mind that some of these same engine issues that are common of a failing EGR valve could also indicate problems in other parts of the system.
  • Rough idle
  • Poor performance
  • Increased fuel consumption
  • Engine stalling while idling
  • You can smell fuel odours
  • Engine light is on erroneously 
  • Increased emissions
  • Knocking or rattling noises from the engine
  • Random engine misfires
  • Oil leak

Can an EGR valve cause rough idle?

Does a faulty EGR valve affect performance?

Can a bad EGR valve cause stalling?

Does a bad EGR valve make noise?

Can an EGR valve cause misfires?

Can a bad EGR valve cause oil leak?

As mentioned above, these are all symptoms of a faulty EGR valve.

Can a bad EGR valve cause white smoke?

Can a bad EGR valve cause overheating?

While a failing EGR valve may cause black smoke, white smoke/steam is actually an indication of a failing EGR cooler. Similarly, a faulty EGR cooler (not the valve) can cause engine overheating if the coolant flow is restricted and therefore unable to cool the exhaust gases.

Can an EGR valve stop a car from starting?

Although a faulty EGR valve may cause a number of problems once the car has started, it shouldn’t prevent the car from starting in the first place.

Can you drive a car with a bad EGR valve?

Can I remove my EGR valve?

Do all cars have EGR valves?

Do petrol engines have an EGR valve?

Do you need an EGR valve?

Technically you can drive your car with a bad EGR valve, but it is not recommended and you’re likely to experience many of the symptoms listed above. Therefore, you do in fact need an EGR valve and should not remove it unless you intend to clean or replace it. Virtually all modern cars have EGR valves, whether they are petrol or diesel.   


How long do EGR valves last?

How to avoid EGR valve problems?

EGR valves have a typical lifespan of approximately 10 years. The best way to avoid any issues is to ensure your vehicle is properly maintained, including cleaning or replacing your valve every 50,000 miles. The best way to go about this is to buy a manufacturer-approved EGR valve specifically designed to fit your vehicle from Autofixa.  
That’s everything you need to know about EGR valves. Now that you have a better understanding of the importance of EGR valves and keeping them clean, the best course of action, if you’re experiencing any symptoms of a failing EGR valve, should be to clean or replace your EGR valve. As mentioned, if you decide to replace your EGR valve, you should ensure you use an EGR valve specifically designed for your car – purchasable through Autofixa.

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