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Why does the diesel particulate filter clog?

The diesel particulate filter is one of the parts that makes up the exhaust system. The filters are installed in vehicles equipped with diesel engines to remove soot and ash particles from the exhaust gases. Most often problems with DPF filters are due to their clogging. What are the symptoms and can it be avoided?

What is the diesel particulate filter?

The diesel particulate filter popularly called DPF is one of parts of the exhaust system installed in diesel engines. The filter, similarly to the catalytic converter, takes part in removing pollutants from the exhaust gases, and more specifically, it reduces emissions of soot into the environment. The device itself looks like a metal container equipped with a special system of parallel channels, where soot particles are deposited. Most often the DPF is located behind the catalytic converter, but it can also be installed in the same container together with it.

Why does clogging occur?

The filter clogging occurs when too many soot particles are collected in the DPF. Quite simply – you drive mostly in the city and consequently you do not create the suitable conditions to burn off the soot particles located in the filter, and therefore the DPF is overloaded and does not work correctly.

Clogged DPF – symptoms

The clogged DPF shows different symptoms – you can see a decrease in performance, uncontrolled increase in revolutions or engine switching to emergency mode. Finally, problems with the filter may even lead to the engine seizure. In some cars it is easy to identify the clogged DPF – if it is overloaded, a special warning light illuminates to inform about the problem.

Burning off the diesel particulate filter

The filter cleaning takes place automatically – when soot particles accumulate in the DPF, they must be burned off. Burning requires the filter to be heated to approx. 600°C. Such temperature is reached when a car is driven with suitable speed and high engine revolutions without changing the gear. The above conditions are especially difficult to reach during city driving, and therefore the filter clogging occurs very often in the vehicles that are mostly used for short journeys and city driving. Manufacturers recommend to burn off the DPF filters every several thousand kilometres, but unfortunately only few drivers follow those guidelines.

Regeneration of the diesel particulate filter

If a problem with the clogged DPF has already occurred, you have two options: regeneration or immediate replacement . Regeneration is carried out by mechanics in the car workshop, by creating special conditions for burning soot particles remaining in the filter. Unfortunately, this process may not bring the expected results, but in spite of that it is worth of trying at least.

Replacement of the DPF

For many the DPF replacement is as a last resort because it is connected with high costs. The device itself is not cheap and additionally there is high cost for its installation. Some decide to permanently remove the diesel particulate filter . This also involves some expenditure, but it is much more lower than during replacement. It must be noted that its removal will be impossible at all in most new cars. In older models it requires some effort, because the filter removal usually requires to reprogram the engine electronic control unit or install an emulator. The emulator enables a car to be cheated in some way, by giving signals that DPF is still working. Of course, permanent removal of the filter is not recommended – it results in the environment pollution, problems with passing a car inspection or car running.

How to save on the DPF?

How to save at least some money during the filter replacement? Sell the worn out device to the purchasing centre that offers the best price. DS Auto is ready to purchase different types of DPF filters.

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