Understanding the Role Of An EGR Valve In Your Diesel Engine

EGR stands for Exhaust Gas Recirculation. The main function of the EGR valve is to return part of the exhaust gas expelled from the engine back into the combustion chamber. This, in turn, reduces the harmful nitrous oxide gases released into the atmosphere. The EGR system is critical to most manufacturers’ diesel engines in order for them to meet the strict and ever-changing Euro emissions standards.

Why Does The EGR Fail?

There are two common ways in which an EGR valve can fail. Most EGR valve assemblies have a built in cooler to lower the temperature of the gases before they re-enter the engine. This cooler is prone to a build-up of carbon deposits, eventually this can become enough to block the system. This will likely cause a warning light to come on the instrument cluster, and possibly a loss of engine performance. Another common type of failure is a mechanical or electrical failure of the valve that controls the flow of gases. Unfortunately this type of failure is in most cases due to the high temperature environment in which the valve operates. This would also likely cause a warning light and possible loss of engine performance; at worst it can cause a complete non start.

Is There Any Way To Prevent Failure?

Unfortunately there is no way to guarantee that your EGR valve will never need replacing. However, there are a few things that can help prevent some types of failure. Keeping up to date with manufacturer’s service schedule and using correct engine oil will help lower the amount of carbon deposits going through the system. If you find yourself doing lots of short, stop/start trips it would be advisable, once in a while, to go for a longer drive where the engine and exhaust can get up to higher temperatures. Both the above can help prevent the cooler becoming blocked.

If It Fails, Do I Need To Replace The EGR Valve?

If left, a failing EGR valve could lead to premature failure of other expensive components e.g the turbocharger and DPF. Also, in some cases your vehicle could break down and leave you with costly recovery charges. Therefore yes, we would always recommend a failing or failed EGR valve should be replaced.

What Is Involved In A EGR Valve Replacement?

The costs for the replacement of an EGR valve can vary depending on make and model. In some cases, the valve can be removed and replaced within 3 hours; others are much more and can be 10 plus hours. In some cases, special tools will be required. Specialist diagnostic equipment will almost always be needed to carry out the required basic settings after replacement. Here at Volks Autos, our brand trained technicians will also check other parts of the system whilst replacing the valve. This is because we are aware that some pipes, etc, can also get blocked. If found to be faulty, we would also replace these to help prevent repeat failures.

How Do I Find Out If My EGR Valve Needs Replacing?

Usually, you will get a generic engine warning light on your instrument cluster. At Volks Autos, our skilled technicians would check the engine control unit for fault codes. If fault codes relating to the EGR system are logged, we will conduct relevant tests and checks. This might lead to a diagnosis of a failed EGR valve. However, it is worth noting that other parts of the EGR system can fail. Therefore we would always advise to have this type of fault diagnosed correctly to avoid expensive and unnecessary replacement of an EGR valve.

If you have any questions on this subject, please contact our friendly service team.

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FAQs

Why do I need to service my vehicle?

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Regularly servicing your vehicle not only ensures its safety but also helps prevent unnecessary additional repairs, keeping it in the best possible condition. Routine oil and filter changes are essential, as the oil lubricates internal components, and the filters collect particles that contaminate the oil during use. By regularly servicing your vehicle, you can avoid costly mechanical repairs in the future and maintain optimal performance.

What service do I need?

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Minor Service: Typically recommended every 10,000 miles or 1 year, whichever comes first.

Minor Service With Pollen Filter: Typically recommended every 2 years or 20,000 miles, whichever comes first.

Major Service: Typically recommended every 4 years or 40,000 miles, whichever comes first.

Please Note: Service intervals may vary depending on your vehicle’s needs and the manufacturer’s recommendations. If you are unsure about the type of service your vehicle requires, our friendly and knowledgeable service team is here to assist you. We can access your manufacturer's technical data, service intervals, and schedules. We will guide you through the manufacturer's recommendations based on your vehicle's age and service history.

What is an air filter?

The function of an Air filter is to help stop contaminants from getting into the engine, helping to extend its life. It also lets the engine breathe more easily, which can help enhance performance and efficiency.

What is a pollen filter?

The purpose of a pollen filter is to stop contaminants getting into your interior via its heating and ventilation system. The pollen filter prevents dust, dirt, soot and pollen entering your vehicle interior. As well as having the added benefit of protecting against pollution gases, exhaust fumes and bad odour.

Must I use a main dealer until my manufacturer’s warranty expires?

You are not required to have your vehicle serviced by a main dealer to maintain the manufacturer's warranty. Thanks to the European Block Exemption regulation introduced in October 2003, you can choose where to service your car. At Volks Autos, our brand-trained technicians ensure that your service follows the manufacturer's recommended schedule using approved parts. We will update your service book or digital service schedule to reflect the completed work.

Can only main dealer update my Digital Service Record?

As a registered German car specialist, we have secure access to check and update your service record for all German vehicles and most manufacturers currently using Digital Service Records. Additionally, we can review your Digital Service Record to provide advice on any upcoming service items that may be due, all in line with your vehicle’s manufacturer specifications. 

Explore Our Guide to Digital Service Records

Can you reset my service light once the service is complete?

Yes. We have all the necessary electronic equipment to be able to reset your service light and variable service indicators once we have completed your service here at Volks Autos.

Do you perform a health check on my vehicle during the service?

Volks Autos Health Check For Service

During your oil change service, our brand-trained technicians will perform a detailed Health Check on your vehicle. This check covers various aspects of your vehicle's health, and the results will be sent directly to your phone, allowing you to see any issues first-hand.

Learn more by visiting our Health Checks Explained

Will you let me know if there is any additional work needed?

We will not proceed with any additional work without your authorisation. If further repairs are needed, your service advisor will contact you with an estimate for the required work.

3rd party warranty – Can I use this at Volks Autos?

Yes, you can use a third-party warranty at Volks Autos. After diagnosing the fault, we can communicate with your warranty company on your behalf, explaining the issue and providing a repair estimate. Typically, customers pay the repair fees to the garage, and the warranty company reimburses them. Most warranty companies require the customer to authorise and cover diagnosis costs before agreeing to contribute to the repair.

Do you offer warranty on repairs you carry out?

We use only the highest quality parts from trusted suppliers and offer a minimum 12-month or 12,000-mile warranty on all mechanical repairs.

Do I need to pay upfront?

Payment is due upon completion of the work when you collect your vehicle. We accept most credit and debit cards or cash. Some special order parts may need to be paid for before ordering.

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