DPF: Diesel Particulate Filter

What is the Diesel Particulate Filter (DPF) and what does it do?

I’m sure you have heard the term DPF before. It’s is basically a part that helps to trap any soot that may be present in the exhaust gas before it escapes the exhaust. As the name suggests, it is only found in diesel vehicles.

Over time your DPF will build too much soot, in which case the DPF system should burn off the soot, allowing the filter to continue its job. Sometimes this may not happen and you will require a manual DPF burn at your mechanic.

Here is a great video from RAS on how the system works.


Someone asked Steve over on Tik Tok how he felt about DPF’s, and he replied with the following.

I don’t have an issue with DPF, generally they flow as much as a straight piece of pipe. The manufacturer’s have ensured this happens. I’m sure there is going to be disagreements on that. 

Alot of vehicles don’t even have a problem with DPF’s. There are some mercedes and BMW’s out there that never have to get touched. They’ve done 400,000kms and have never needed a regeneration. They just work properly. 

A lot of it comes back to maintenance. For an example, that MP300 that I did a burn on, on Saturday, it had a fault code for insufficient oil quality. Now, once that code is logged there is no chance of it doing a burn. The problem is, that is was serviced 2,000kms ago, and the fault codes weren’t checked and cleared to say that it had new oil installed. So, that could of been prevented and that sort of what I am trying to get to; meaning maintenance IS key to everything. 

If you maintain your vehicle properly, you clear the codes, you check everything and then it should work fine.

So, how do you know when you need a DPF burn?

Unfortunately, the only way that you can tell, usually means it is too late. It’s when the engine light comes on. Sometimes you can bring it back from that point. Other than that, in general servicing your mechanic should be checking your soot level and checking all the fault codes that are in your computer. So, that is just one other way we check to see if it needs a burn or recommend it at the time of service. Generally, you dont want to get it to the point where your engine light is on.

Learn about other diesel FAQ’s on our recent post. Also have a read about a common mistake of putting the wrong fuel into your diesel car.

Book in for your service now and make sure that your car is maintained.  Learn more about why you should service your car and be sure to download our Apple app or Google app to keep a track of your vehicle history and make sure that you dont miss a service.