What To Do If Your Car's Self-Cleaning DPF Doesn't Do Its Job

13 January 2022
 Categories: , Blog


Not all that long ago, diesel-engined cars or trucks were considered to be the "bad boys" of the industry. They were classified as heavy polluters, and regulators took some Draconian steps to bring them back into line. Today, the situation is very different, and your vehicle will be fitted with a special part known as a diesel particular filter to keep it clean. But what can happen if this device doesn't do its job?

The Role of the DPF

A diesel particulate filter (DPF) is fitted halfway down the exhaust system in between the engine manifold and the tailpipe. As exhaust gases come out of the engine, they flow through the filter and the most harmful particulates are trapped. The remaining emissions are then allowed to exit the device and out into the surrounding atmosphere.

Automatic Maintenance

These devices are quite dynamic, however. When the trapped particulates build up to a certain level, special sensors will initiate a programme of events that will safely burn off the fragments in the regeneration phase. This will all be done effectively without creating any additional pollutants so the device is always ready to function at maximum efficiency.

Often, this process will be controlled by the vehicle's ECU and will operate according to preprogrammed parameters. Sometimes, the vehicle must be driven at motorway speeds for a specific period of time before the regeneration process can be triggered.

When Things Go Wrong

Occasionally, the device will not work as intended. For example, an internal sensor may fail, and the particulates could build up to such a level that the entire device becomes blocked. This will cause pressure to build up between the exhaust manifold and the filter leading to a drop off in vehicle performance. The car would almost certainly fail an emissions test at that point until action was taken to fix the issue.

Your Options

It may be necessary to replace the entire unit in a situation like this. Alternatively, a mechanic could initiate a chemical cleaning process to remove the excess contamination and restore normal service. While they are performing this work, they would also check the software version to see if it is up-to-date or if it may need to be revised in order to prevent further issues with the DPF.

Scheduling the Work

Ask your mechanic to check the condition of your DPF, especially if you're encountering some performance issues with the vehicle. They will repair the part and reprogram the software as needed. Contact a European car repairs service near you to learn more.


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