Products and methods for cleaning an EGR valve

Who hasn't heard of a clogged EGR valve ? In fact, it can happen much more quickly than you might think.

This valve, which is designed to reduce pollution, fulfils a very specific role. It is extremely effective in recycling exhaust gases by injecting them a second time into the engine.

However, this operation produces a deposit that can eventually lead to clogging. This is even more the case for diesel-powered cars, most of which are driven in urban areas. Here are our recommendations and methods for limiting this phenomenon.

By the way, what is an EGR valve ?

Let's start by briefly reviewing how an engine works. For an engine to work, it needs a mixture of air and fuel.

The fuel comes from the injectors, from the petrol or diesel tank. For the time being, it is drawn in through the intake while driving, after passing through the air filter.

It then passes through the turbocharger before reaching the engine. The engine then emits exhaust gases, in particular nitrogen oxides.

When an engine is running at low speed, the particles will intensify. Despite the presence of the diesel particulate filter at the end of the exhaust line, a device was needed to regulate a large proportion of the polluting emissions. This is the role of the EGR valve.

This valve is traditionally located at the engine outlet. It is similar to a flap valve.

When the engine is running at low revs, it opens. This allows the exhaust gases to pass through a hose and be injected back into the engine. When the engine reaches optimum operating speed, the gases are directed into the second channel of the turbocharger before arriving in the catalytic converter and the diesel particulate filter.

The EGR valve therefore performs an initial filtration function. It has been fitted to all diesel-engined cars since the 1980s, and more recently to petrol-engined cars. Tougher environmental standards have forced carmakers to increase the number of anti-pollution devices... While effective, the risk of clogging is very real..

Why does the EGR valve clog ?

The EGR valve acts as a sort of bypass for the exhaust gases emitted when the engine is running at low speed. Naturally, a soot deposit can form more or less quickly. The intake valves and ducts are also directly exposed to this problem.

To make matters worse, low-quality fuel can also clog up the valve, which can accumulate the amount of deposit. After a while, these can create a blockage.

Insufficient maintenance of the engine and its peripherals can also lead to an increase in pollutant emissions, which can saturate the valve. Unsurprisingly, the rate of clogging can vary according to these different parameters.

The fact remains that if a diesel-powered car is used mainly in urban areas, this phenomenon can increase significantly. So, is there a miracle remedy for cleaning an EGR valve ?

How do you clean an EGR valve ?

One well-known tip for cleaning an EGR valve is to drive fast. However, it's important to qualify this a little ! The aim is not to maintain a speed of 150 km/h for 10 minutes. Not at all !

The aim is to raise the engine speed to a higher average than usual. In practical terms, on the road or on the motorway, drop one or two gears. The engine will be noisier and fuel consumption will increase, but the increased air flow may help to force the EGR valve to eliminate some of the impurities that are blocking it.

Another solution, which is mainly for good mechanics, is to lift the car and remove the EGR valve. It's not a particularly complex operation, but you need to be able to do it safely and, above all, have the necessary tools and skills.

The valve must be disconnected from the engine before being cleaned with a special solvent. This is very effective, but requires time and tools. This solution is not recommended for do-it-yourself use. However, you can ask a garage to do it for you.

The cost varies considerably from one establishment to another. It will depend on the reputation of the establishment, but also on how complex it is to access the part, as it will take longer to dismantle and reassemble.

You should also consult your car's owner's manual. There's usually a section devoted to the EGR valve. Sometimes there's a method or recommendations for dealing with clogging. It is often advisable to use products..

Can products be used ?

Yes, there are products that can be used to clean the EGR valve. These are generally additives that you add to the fuel tank when you fill up with diesel. The product removes soot deposits by acting directly on the intake system, the valves and the valve itself.

But don't be fooled... These products are first and foremost maintenance products. If the EGR valve is completely blocked, an additive won't work miracles. However, these products are recommended. You can use them regularly to prevent clogging, especially if your car is used mainly in urban areas.

There are also products in aerosol form that can be sprayed directly onto the valve. To do this, disconnect the air intake system from the valve and then spray directly at the inlet. This should be done when the engine is warm..

Prevent clogging of an EGR valve

Preventing the EGR valve from clogging is not very complicated. First of all, if you drive mainly in town, you need to get into the habit of making slightly longer journeys from time to time. This will also benefit the diesel particulate filter, which will be able to maximise its regeneration phases.

The last piece of advice is also to avoid driving at low revs. It may seem like a good way of reducing fuel consumption... but it's also the best way of creating general clogging. So it's best to adopt a sufficiently dynamic driving style to avoid prematurely wearing out your car's various anti-pollution devices.

Alternatively, using an additive on a regular basis can also be a good way of extending the life of the EGR valve. This will limit the risk of clogging while having a positive impact on your car's fuel consumption.

Things to remember

The EGR valve plays an important role in reducing pollutant emissions. The various changes in Euro standards are forcing car manufacturers to come up with new ideas to reduce the environmental impact of their vehicles.

The EGR valve fulfils its role effectively by allowing exhaust gases to be reinjected into the engine a second time. This improves air quality while reducing pollutant emissions into the atmosphere.

However, there is a real risk of clogging if we are not careful. Get into the habit of making long enough journeys from time to time, and avoid driving at low revs. Your car's EGR valve will be all the better for it... and so will your diesel particulate filter !

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Karolina Osinska / Author: wirestock / Licence ID: ZCPA6Q83DS - elements.envato.com