Diesel Particulate Filter Cleaning Explained

Ellie Dyer-Brown, 10 days ago

3 min read

  • Cost
  • Maintenance
  • Exhaust
Orange car with black exhaust smoke

WhoCanFixMyCar explains what's involved in DPF cleaning and how much it's likely to cost.

The diesel particulate filter is a device in the exhaust system of diesel cars that reduces harmful NOx emissions by capturing and storing soot. It is designed to clean itself in a process called regeneration.

However, if you make many slow, short journeys, the DPF can become blocked and may not be able to regenerate. When this happens, booking a professional diesel particulate filter clean could help get your car back on the road.

Contents

How to clean a diesel particulate filter What is DPF cleaning?

Why should I get my DPF cleaned?

Signs your DPF needs cleaning

How much is a DPF clean?


How to clean a diesel particulate filter

There are a few ways to clean a DPF. The first is to try to trigger a regeneration cycle by driving at least 40 mph in a low gear and sustaining a high RPM.

A diesel particulate filter seen from below

Another method is to purchase a DPF cleaning fluid and add it to the fuel tank. This is good as a preventative measure, but it can’t work miracles. If the blockage is too severe and your car has gone into limp mode, a cleaning fluid is unlikely to work.

The final option is to book a DPF clean to clear the most severe blockages and restore your filter without replacing it, which can be expensive.

Find out how to avoid DPF problems in this guide.


What is DPF cleaning?

DPF cleaning is a professional workshop treatment. It involves using aqueous cleaning technology and chemicals to remove soot and ash. 

A few techniques exist, meaning the process can vary from one garage to the next. A typical aqueous DPF clean might involve the following steps:

  • The DPF is removed and inspected for internal damage to determine whether it can be cleaned or needs replacing.

  • A back pressure test is used to check the blockage level.

  • The DPF is put in a specialist cleaning machine and undergoes a two-way aqueous clean and drying procedure to remove all soot and ash.

  • Another back pressure test is carried out to confirm the cleaning has been successful.

  • The DPF is reinstalled.

Ultrasonic cleaning

During an ultrasonic clean, the DPF is submerged in an aqueous solution and subjected to ultrasonic waves, which disrupt the cleaning solution, creating microscopic bubbles. When the bubbles collapse, they release hot jets that are forceful enough to dislodge contaminants - a process known as cavitation.

Kiln clean

A kiln clean is straightforward: the DPF is put into a kiln and heated up to hundreds of degrees, burning away the soot.

Pressure pulse clean

Pulse cleaning uses a high-velocity, low-pressure air pulse to remove accumulated ash and soot.


Why should I get my diesel particulate filter cleaned?

When your DPF becomes clogged, it decreases engine power and fuel efficiency. Eventually, your car may go into limp mode. Continuing to drive with a faulty DPF can also cause problems with the turbocharger due to increased back pressure and heat, resulting in an expensive repair bill. For these reasons, it is important to keep your DPF in good shape and clean it when necessary.


Signs your DPF needs cleaning

Diesel particulate filter dashboard warning message.

The following symptoms are common when your diesel particulate filter needs cleaning:


How much is a DPF clean?

The average price of a DPF clean is £188.29. The table below shows how prices vary across different car makes.

Car MakeAverage Price
Audi£189.40
BMW£192.21
Citroen£181.61
Ford£183.43
Mercedes£189.39
MINI£185.97
Nissan£184.74
Peugeot£188.69
Renault£191.88
Toyota£177.61
Vauxhall£183.24
Volkswagen£194.63
Volvo£183.36

Is your car showing signs of DPF failure? Whether you need to book a diesel particulate filter replacement or clean, WhoCanFixMyCar can help you find the right garage at the right price.

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