Soot filter problems? How to prevent them

Has a mechanic ever sent you out on the highway? He probably did this because there were problems with your particulate filter. If you have a diesel car that you don't drive much on the motorway, you should read this post about particulate filters and DPFs. This filter is located in the exhaust system and removes particles and pollutants formed during combustion. These particles are also known as fine dust and represent a health risk. Most diesels from after 2005 are equipped with a particle filter. These are mandatory from that year of construction so that they could comply with the Euro 4, 5 and 6 emission standards. 

How does a diesel particulate filter work? 

The particulate filter traps the harmful particles so that they can be burned later during the filter regeneration process. This converts them mainly into carbon dioxide and water.Filter regeneration takes place every 300 kilometres. A car with a particle filter is equipped with an electronic control unit that calculates the volume of particles accumulated and indicates when the process to remove them should ideally take place. To remove the particles, the particulate filter must operate at more than 400 degrees Celsius. If this is not the case, the filter may become clogged and have problems retaining the aforementioned particles. 

This is quite common in the situations below:  

  • if you only drive in the city, 
  • if you usually do not drive more than 60 kilometres per hour, 
  • if you use your car mainly for short trips or if your engine is idling a lot.

Good maintenance alone is often not enough

A particulate filter can cause problems, even with regular maintenance. The particulate filter light or emission fault will probably come on at some point if the car is driven many short distances. If this happens, you may also experience loss of power and an increase in fuel consumption.

"It may seem unfair: why is this light on, when you always maintain your car properly!" 

Cause of emission failure 

The reason why your vehicle does not remove the solid particles is because the particulate filter cannot regenerate because the exhaust does not get hot enough. So the particles accumulate in the filter and block the exhaust. In other words, your car is choking and screaming for help.

Fortunately, there is a simple solution 

Prevention is better than cure. If you regularly drive small distances, it is advisable to drive for at least 30 minutes on the motorway, and not at too low a speed. Just keep to the maximum speed of 130 km/h. The car may make a jolt. Don't worry, this only means that your exhaust has been cleaned and your car is now back to normal. The power of your engine will go back up and you will use less fuel.
So if you do a lot of city driving, regularly cover short distances or usually drive no more than 60 kilometres per hour, make sure you set aside a little time each week for your car. If this is not possible, try to squeeze a little 'car time' into your busy schedule every 200 or 300 kilometres. Regularly take a stretch of motorway where you are allowed to drive at 130 km/h. This reduces the chance of the particulate filter becoming clogged and an emissions warning light coming on.