DPF Problems, Symptoms and Fixes

The Diesel Particulate Filtration system (DPF) is most beneficial referred to as the “ ticking time bomb ” in most modern diesels. Similar to EGR problems , the DPF can become clogged up from city driving where the car does not get right up to temp.

The complete cause the Diesel Particulate Filtration system arrived was to completely clean in the diesel car picture (Euro 5 Emissions, 2009). Emissions from diesel cars are a big concern worldwide and thanks to the DPF technology, diesel cars are much cleaner.

DPF’s are excellent for the surroundings etc, however they certainly are a correct pain if they fail . DPF regeneration , maintenance and new replacements are seriously expensive and can lead to some vehicles becoming scrapped.

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How does a DPF Function in Diesel Vehicles?

The Diesel Particulate Filtration system traps the dangerous diesel gases that gets washed regularly by an activity known as DPF regeneration . The gathered diesel soot contaminants are burnt off at high temperatures , which results in an “ ash-like ” after product. After the regenerating of the DPF, it can now restart the cycle of collecting harmful exhaust gases once again.

You can find 3 various kinds of DPF regeneration, that are energetic, passive and compelled.

Energetic DPF Regeneration

Energetic reads the trunk pressure from the exhaust or soot load of the filter to determine when to begin the regeneration. Once initiated, the timing of the fuel injection will alter that will result in the exhaust temperatures increasing to burn off the soot contaminants.

During a dynamic DPF regeneration, you might notice the pursuing:


  • Higher idle RPM/Rate
  • Cooling enthusiast working significantly harder
  • Poor energy economy
  • Smells from exhaust
  • Engine take note change


Passive DPF Regeneration

Passive will take place once the exhaust reaches optimum temperatures where the regeneration will automatically begin. The exhaust will reach these temperatures will occur mostly on prolonged highway driving. Manufacturers that make use of a passive type of regeneration typically use a oxidizing catalytic converter close to the engine to improve the temperatures.

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Compelled DPF Regeneration

Forced is usually where the Active regeneration could not occur that has resulted in the soot levels reaching 70% and above. The diesel car will enter limp mode and will need a diagnostic device to drive the regeneration. Its essential that this is performed at the earliest opportunity because after the car gets to 85% soot level, the DPF should be eliminated and cleaned.

What causes DPF failure?

Sadly DPF’s do fail and many diesel car owners do not realize the way they are leading to a obstructed DPF. The primary reason for DPF’s declining is because of car owners not really doing enough mls and driving too often in city areas.

How long until a DPF will fail is definitely hard to tell because some manufacturers have had to replace some in the 1st 3 years and some hardly ever. The most common known reasons for DPF failures are:


  • Brief journeys where in fact the engine doesn’t reach ideal operating heat range
  • Clogged EGR Valve increasing diesel soot approved to the DPF
  • Faulty gas injectors sending too much fuel to the air/fuel mix
  • Wrong engine essential oil upon servicing the automobile – ( Low Ash + Low Sulphur necessary for DPF Cars)
  • Turbo faltering with oil dripping into the DPF
  • Large mileage car that may find regeneration harder



Symptoms of a Block DPF Filter

As the majority of DPF’s are installed on newer cars, you will more than likely have a trip computer. Error codes like the DPF light or EML (Engine Administration Light) would be the 1st symptoms of a faltering DPF.

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However, occasionally these warning lamps could be false alarms and you should try clearing the fault using an OBD2 diagnostic tool . If the warning light continue to display, you will notice the next symptoms:


  • Lack of power
  • Reduced energy economy
  • Poor throttle response
  • Harder or failing to start out
  • Limp setting ( probably )
  • Poor smells


How to Clear a Blocked DPF and Keep it Clean

The cost of cleaning or replacing your DPF sounds scary but you can forget this pursuing some simple traveling habits. The primary reason DPF’s obtain blocked is because of short trips and town driving. With that in mind, here are 5 ways to fix a blocked DPF:


  1. Drive Faster . If you are driving slowly everywhere in your huge diesel, the DPF can be blocked. Boost your swiftness and seed your foot to floor to when accelerating to increase exhaust temperature and very clear soot amounts.
  2. BOOST YOUR RPM . If the DPF light is usually on, your best bet is to drive at high RPM’s for a prolonged period until the warning lights turn off. This will increase the gases going through the DPF, hence clearing it and raising the temperatures.
  3. Avoid Town Centers . When possible, you should prevent slow visitors where possible, particularly if you are nearing your DPF limit or have the light currently on.
  4. Check EGR Valve . If you have problems with your EGR valve, it will be also harder to apparent the DPF. Repair the EGR concern and try the various other steps.
  5. Make use of High Quality Gasoline . Premium fuels or diesel gas cleaners include gas additives that help burn off harmful particles.
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If you are currently in limp setting, generating at high RPM (step two 2) will end up being your best possibility of getting away from limp mode. Once you've normal power, get a very long fast travel on high quality gas. If the issue remains the next day, make your error rules read with a diagnostic device .

Take away the DPF in the Exhaust Program

The DPF delete is an appealing aspect if you are having issues with your DPF. It is true, without a DPF, you should have no problems and actually, your performance increase having a remap or tuning of the ECU.

However, the DPF removal may be illegal is your country and it will cause even more environmental damage. However the latter will never be your biggest concern.


The expense of cleaning or changing your DPF could be expensive. In most of DPF’s, if you're around 70 to 85% it'll be eligible to become cleaned. Any greater than 85%, the DPF should be replaced with a new system.

Many people bought diesels as it was marketed as the “fuel for saving the planet”. However, they didn't wager on having problems such as for example DPF failing on relatively new cars costing thousands.

It is not the Diesel Particulate Filters fault the majority of the time. Its your traveling habits as the automobile owner and insufficient knowledge with contemporary diesel vehicles.

If you're driving several miles each day, your DPF will eventually give up and repair bills will start piling up. A gasoline engine is perfect for brief journeys and just as efficient on energy.

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