How To Clear A Blocked DPF – 3 Solutions/Fixes

How To Clear A Blocked DPF

At Phantom Tuning, a large number of our enquiries come from individuals with blocked DPF faults. In this article, we’ll explain how to clear a blocked DPF and hopefully save you time and money!

There you are, driving along and BOOM – engine warning light, limp mode, power loss, rev limiter restricted and top speed restricted. Your vehicle drives awfully, doesn’t run as it should and your heart sinks. You’ve been hit by a DPF fault, most likely to be caused by a blocked DPF. The bad news is: this is a problem. The good news is: there are many tried and tested solutions.

Alternatively, your DPF blockage may be so bad that the car won’t even start! Either way, Phantom Tuning can help and if you’re not local, feel free to try one of the solutions at the bottom of this article with your local firm.

***If you only want to find solutions, click here to automatically scroll down to that part of the article.***

What Causes a DPF Warning Light?

A DPF warning light can be caused for a large number of reasons, most commonly:

  • DPF blockage
  • Sensor faults in the exhaust
  • Exhaust mechanical faults
  • ECU faults

The best course of action if you have a DPF warning light is to bring it to a mechanic to complete a full diagnosis. Most diagnostic machines will show the fault code that the ECU stores when there is an engine management light. These codes are associated with more specific explanations of where the fault lies. The mechanic will be able to tell you where and potentially what the fault is. If the fault is indeed DPF related, it’ll need fixing.

How Does A DPF Work?

DPF stands for Diesel Particulate Filter. The purpose of a DPF is to reduce the number of harmful materials released into the environment during the engine’s combustion cycle. The filter catches soot and other deposits as they’re on their way out of the engine, through the exhaust system, before they exit the tailpipe.

As time goes on, these deposits build up and become a solid. If the solid remains in the exhaust, the engine cannot exhaust properly and therefore, the combustion cycle is disrupted. To stop this from happening, a DPF will go through a ‘regeneration cycle’. A regeneration cycle occurs when the DPF system gets very hot. At this point, the solid deposits vapourise and turn into a gas that is less harmful to the environment than when they originally exited the engine.

Causes Of Blocked DPF’s

Short Journeys

Unfortunately, a regeneration cycle can only occur when the DPF and exhaust system maintains enough heat to vapourise the solids. This usually happens during motorway or long A road driving when the vehicle has sat over 2500RPM for 10 minutes or so.

Diesel vehicles are aimed at a target market of individuals that tend to do long distance driving as these vehicles maintain higher MPG if driven on motorways. Diesel vehicle owners that do not complete regular long journeys are effectively in the wrong car. A petrol engine is more suitable.

Driving a diesel vehicle around town and for mostly short journeys without regular motorway travelling is the main cause of DPF blockage. Ultimately, during your short journey drives, the DPF is building up carbon deposits and due to the lack of motorway driving, the DPF has no opportunity to regenerate.

Previous Owner Driving

When it comes to buying a second-hand or pre-owned vehicle, you’ll complete all of the necessary due-diligence before purchasing. However, one thing that you cannot be certain of, is the types of journeys and historical journeys that the vehicle completed before you purchased it. The DPF may have been fine at the time of purchase but if the motor wasn’t a frequent motorway user, the DPF could already be on its way out due to the above-mentioned problems.

Vehicle Age & Mileage

Through our experience, we see that most DPF’s start to go at around 80,000-120,000 miles. If you’re in a vehicle which does the odd motorway drive here and then, you may be in the 80,000 range. However, if you frequently motorway drive, you may even get 120,000-150,000 miles out of your DPF.

How Can I Fix A Blocked DPF?

If a professional diagnosis of the vehicle fault determines that the DPF is blocked, there are a few options:

  1. DPF Regeneration
  2. DPF Clean
  3. DPF Delete

It’s worth noting that with solutions 1 and 2, there is no guarantee that you’ll be DPF problem-free afterwards. This is due to the type of driving that you mostly do. Ultimately, if you’re doing short journeys before you solve the problem, you’re going to be doing short journeys after you’ve solved the problem. Meaning that if you choose option 1 or 2, you may see the dreaded DPF light again.

DPF Regeneration

DPF regeneration is built into your ECU. Some people tend to find that this is a temporary fix – and generally speaking, it rarely permanently fixes the issue – however, it’s worth a go as all it’s going to cost you is 30 minutes of your time and £5.00 in fuel!

What you should do is get in your car, drive to the nearest motorway or long A-road, stick it in a lower gear than you normally would while cruising and maintain 3000+RPM for 10-20 minutes. You may find that this allows your vehicle to go through its regeneration cycle and clears the blockage.

If this does fix the problem and you don’t want to pay for any of the below options, make it part of a weekly driving routine to do this.

DPF Clean

At Phantom Tuning (and many other reputable motoring firms in the UK) we have access to a specialist DPF cleaning machine. You can bring your vehicle OR your DPF to us. We’ll put your DPF through our cleaning machine, designed specifically for DPF’s. Once it is cleaned, it should be good as new.

This solution is preferable for vehicles that have mild to mid-range blockages in the DPF.

DPF Delete

This is the only solution that will 100% guarantee that you’ll never have a DPF problem with your vehicle ever again. This solution offers the best ‘peace of mind’ factor.

The process of a DPF delete involved the following process:

  1. Removal of DPF casing
  2. Cut open DPF casing
  3. Removal of filter
  4. Welding of casing
  5. Casing returned to the vehicle
  6. Reprogramme of the ECU to eliminate fault codes, regeneration instruction and unneeded sensor instructions

Effectively, what occurs here is that the physical problem of stopping the engine from combusting correctly is removed. Then, the ECU is reprogrammed in a way so that it is no longer aware that a DPF exists. No DPF = No more problems.

It is worth noting that there are particular laws around the removal of DPF’s for vehicles being used on public roads. It is advised that you discuss the process with your mechanic to decipher whether or not this is a suitable and legal option for you.

So, there are 3 solutions on how to clear a blocked DPF! If you’re local to Swanscombe, Kent and would like to enquire about our DPF Delete or DPF cleaning solutions, feel free to get in touch using one of our contact forms or give us a call. We’ll be happy to advise the most suitable solution for you.