
The Pros and Cons of Buying a Car with a DPF Filter: Is It Right for You?
Should You Buy a Car with A Dpf Filter. A diesel particulate filter (DPF) is a device that is designed to reduce the amount of soot and other pollutants emitted from a diesel engine. The DPF works by trapping the soot particles in a filter, which needs to be periodically cleaned or replaced. This helps to reduce air pollution and improve fuel efficiency.
The diesel particulate filter (DPF) is an essential component of modern diesel cars designed to reduce exhaust emissions. It captures and stores soot particles to reduce the number of harmful pollutants released into the atmosphere.
As the DPF has a finite capacity, it must be periodically emptied or ‘burned off’ to regenerate it. This process cleanly burns off the excess soot deposited in the filter, reducing emissions and preventing black smoke from being emitted when accelerating.
The introduction of Euro 5 exhaust emissions legislation in 2009 made DPFs mandatory for all new diesel cars. Since then, around half of all new cars sold yearly have been powered by diesel engines, making them an increasingly popular choice for drivers looking for a more efficient and environmentally friendly option.
DPFs have helped significantly reduce car CO2 emissions, making them an essential part of modern automotive technology.
Should You Buy a Car Fitted with A Dpf?

When buying a car, one of the most critical decisions is buying a diesel car fitted with a DPF. The costly repair bills for DPFs that some car owners have experienced have raised concerns among car buyers, prompting many to ask if they should buy a car with a DPF.
Whether you should buy a diesel car with a DPF fitted depends on how much driving you will be doing and if it will be local to motorway driving.
Suppose you do most of your driving at urban speeds and never take your car on a dual carriageway or motorway. In that case, you’re better off choosing petrol over diesel, saving yourself from potential hassles and extra expenses.
Also, suppose you cover less than 12,000 miles a year. In that case, you’re probably better off with a petrol car as diesel cars are generally more expensive to buy new and it will take a long time for the improved fuel economy that they offer to make back the extra money you spent when you originally purchased the car.
However, if you do lots of faster driving, having a DPF shouldn’t be an issue as long as you follow the recommendations in the handbook and pay attention to any warning lights.
Why The DPF Goes Wrong
This occurs when the exhaust doesn’t get up to temperature, and the soot isn’t burnt off. The engine management system will alert the driver when this happens, usually through a dashboard warning light.
To fix this issue, drivers should take their cars on a long drive above speeds of 40mph for 10-15 minutes to allow the regeneration process. During this time, the soot particles trapped in the filter will burn away, and the warning light should switch off.
Drivers must understand how their car works and what to do if something goes wrong. Regularly taking your car on longer journeys can help prevent DPF blockages from occurring, as it allows for regular filter regeneration.
If you cannot do this, you may need to have your DPF manually cleaned or replaced by a professional mechanic. Taking care of your car is essential for running it smoothly and avoiding costly repairs.
What to Do if You See the Warning Light
Seeing the orange warning symbols on your dashboard can be a stressful experience. It means something is wrong with your vehicle, and you must act. The warning lights are triggered by sensors in your car’s computer that detect issues with engine performance. This could be anything from low oil levels to a clogged diesel particulate filter (DPF).
If you see the warning light come on in your diesel vehicle, it is essential to take action as soon as possible. The DPF (Diesel Particulate Filter) warning lamp indicates that the filter needs to be regenerated.
Soot has built up and must be burned off to clear any blockage. To do this, you should take the vehicle on a longer run at 40mph or more for 10 minutes. This will prompt the DPF to enter regeneration mode and burn off the soot.
You must also check your handbook for information about your particular DPF warning lamp, as they can vary from vehicle to vehicle. If you are unsure how to proceed, it is best to consult a qualified mechanic who can advise you on how best to regenerate your DPF and keep your engine running smoothly. Taking action quickly when you see the warning light will help ensure your diesel engine continues running optimally for years.
Can the Dpf Just Be Removed?
The DPF is designed to capture and store exhaust-soot particles before they are released into the atmosphere. This helps reduce air pollution and meet emissions standards set by regulatory bodies.
If you remove your DPF, you will violate these standards and could face hefty fines or other penalties. Additionally, removing the DPF can cause engine damage due to increased back pressure in the exhaust system. This could lead to costly repairs down the line. For these reasons, it is best to avoid removing your DPF altogether.
Removing a DPF (Diesel Particulate Filter) from your vehicle may seem attractive. After all, it could potentially make your car more efficient and cost-effective to run. The internet is full of tips, insights, and services that promise you won’t face any penalty for removing the DPF. However, this is not the case.
The removal of a diesel particulate filter can have severe repercussions in the long term. Not only will you be breaking the law by tampering with emissions equipment, but you may also be putting yourself and others at risk due to increased air pollution.
Additionally, if caught driving without a DPF installed, you could face hefty fines or even criminal charges depending on where you live. In short, removing a DPF is not worth the risk or potential penalties that come with it.
Is It Illegal To Remove a Diesel Particulate Filter
Removing a diesel particulate filter (DPF) is illegal in the UK. This is because DPFs are designed to reduce emissions from diesel engines, and removing them can have a negative impact on air quality.
Owners caught removing their DPF face fines of up to £1,000 for cars and £2,500 for vans.
Furthermore, removing a DPF can invalidate your car insurance policy, leaving you liable for any costs associated with an accident or other damage caused by your vehicle.
What Causes a Diesel Particulate Filter Blockage?
A blocked diesel particulate filter is a common problem for drivers of diesel-powered vehicles. The primary cause of this issue is short journeys at low speeds, which can lead to the filter clogging with soot and other particles.
This is why car makers often recommend that city-bound drivers choose petrol cars instead of diesel. Poor servicing can also contribute to DPF blockages, as can using the wrong type of oil or performance modifications. Low-quality fuel and frequently running the car on a low fuel level can also damage the filter, possibly preventing regeneration from saving energy.
In addition to short journeys, poor servicing can also lead to DPF blockages. You must use the correct type of oil and keep up with regular servicing intervals to ensure your filter remains unblocked.
Performance modifications can also damage a DPF, as can using low-quality fuel and running the car frequently on a low fuel level. If you want your DPF to last for at least 100,000 miles, you must consider all of these factors when driving your diesel vehicle.
Make sure your vehicle is serviced regularly and with the right type of oil to prevent DPF blockages. Generally, a well-maintained diesel particulate filter should last at least 100,000 miles before needing replacement.
If you’re driving in an urban environment or making frequent short trips, it may be worth considering switching to a petrol engine instead to reduce the risk of DPF blockage.
How Do I Maintain a Diesel Particulate Filter?
For optimal regeneration of the DPF, the exhaust gas temperature (EGT) should be around 250°C. For this to occur, your vehicle must be in excellent condition. Any mechanical issues or problems with the engine may prevent proper regeneration and cause the filter to become clogged.
Therefore, before replacing your DPF, it is important to have a mechanic inspect your vehicle to determine whether any underlying issues are preventing regeneration. If so, these issues must be addressed first for the successful regeneration of the filter.
Passive regeneration is the most common way to maintain a diesel particulate filter (DPF). This process occurs when the engine runs at normal operating temperatures, and the exhaust gases are hot enough to burn off the soot accumulated in the DPF.
The exhaust heat helps oxidize the soot, which then exits through the tailpipe as ash. Passive regeneration can occur naturally over time but may take longer than active regeneration.
What Is Passive Regeneration
Passive regeneration is a process that helps clean a vehicle’s diesel particulate filter (DPF). It occurs when the car runs at speed on long motorway journeys, which increases the exhaust temperature to a higher level and burns off any excess soot in the filter.
The exhaust heat helps oxidize the soot, which then exits through the tailpipe as ash. Passive regeneration can occur naturally over time but may take longer than active regeneration.
This driving should be done regularly for it to be effective, and it is advised that drivers give their diesel vehicle a good 30-50 minute run at sustained speed on a motorway or A-road.
Unfortunately, not all drivers do this driving regularly, which is why manufacturers have designed an alternative form of regeneration. This involves engine idling, which can be harmful due to releasing pollutants into the atmosphere.
To combat this issue, many governments have implemented stricter emissions standards, such as Euro 1 to Euro 6, designed to reduce vehicle emissions and help protect our environment.
What Is Active Regeneration
Active regeneration is a more aggressive approach to maintaining a DPF and requires intervention from an operator or technician. This process involves injecting fuel into the exhaust stream, which increases its temperature and helps to burn off any accumulated soot.
Active regeneration can be done manually or with automated systems, depending on your vehicle’s make and model. It’s important to note that this type of regeneration should only be used when necessary, as it can cause additional wear and tear on your vehicle’s components.
Active regeneration is a process that helps to reduce the amount of soot stored in the exhaust filter of a vehicle. This is done by injecting extra fuel into the engine as part of the vehicle’s ECU when the filter reaches a predetermined limit (normally about 45%).
This raises the temperature of the exhaust and burns off any stored soot. However, if the journey is too short, then it may not be possible for the regeneration process to complete fully. In this case, a warning light will continue to show that the filter is still partially blocked.
Driving for at least 10 minutes at speeds greater than 40mph is necessary to complete a regeneration cycle and clear this warning light. Specific symptoms, such as an engine note change, can be observed during active regeneration.
It is important to watch these signs to ensure that active regeneration has been successful and that your vehicle’s exhaust filter remains clean and efficient.
What Do I Do if Neither Active nor Passive Regeneration Works?
One option available is forced regeneration, which usually costs around £100 and has a high success rate in removing the excess soot and allowing the DPF to work again.
When passive and active regeneration does not work to clean a diesel particulate filter (DPF), an operator-activated parked regeneration may be necessary. This process requires the vehicle to be stationary and the engine to reach operating temperature.
The driver or technician then activates the dash controls to initiate the parked regeneration, which can take anywhere from 20 minutes to an hour, depending on ambient conditions and engine type or DPF system.
The driver or technician must ensure that all exhaust outlets are directed away from any structures, vegetation, trees, flammable materials, or anything else that may be damaged by exposure to high heat before initiating a parked regeneration. Not all DPF systems have this feature available.
Parked regeneration is a valuable tool when other methods of cleaning a DPF fail, but it should only be used as a last resort due to its potential for damage if not done correctly. Drivers and technicians need to understand how this process works to ensure it is done safely and correctly whenever needed.
With proper knowledge and care, parked regeneration can help keep your vehicle running smoothly without causing any harm.
Failure to correctly regenerate is often the cause of most DPF issues, resulting in increased exhaust emissions, stifled engine performance, and sometimes even putting the car into a restricted ‘limp-home mode.’
On some models, the engine may not restart after a certain number of miles – consult your handbook for details. If you have doubts or concerns about your vehicle’s DPF system, it is best to seek professional advice from a qualified mechanic or technician.
What Is the Cost of A New Diesel Particulate Filter?
A new diesel particulate filter (DPF) can be pretty expensive. A new one from a car manufacturer can range anywhere from £1,000 to £3,500, which could potentially wipe out any cost savings associated with driving a diesel vehicle.
As cars age and accumulate more miles, the cost of the replacement DPF could be more than the value of the car itself. This is especially true for older, higher-mileage vehicles most likely to require a new DPF.
Fortunately, there are now other suppliers of diesel particulate filters that charge less than car manufacturers. However, it is essential to be careful when selecting these alternative suppliers as they must still have the correct Type Approval, or they may not work correctly and cost you more in repairs. It is always best to research before purchasing a new DPF.
What to Do if You See the Warning Light
Modern diesel vehicles have various sensors that monitor your engine’s performance. When these sensors detect any issues, they report them to the vehicle’s computer, which triggers the orange warning symbols on your dashboard. Seeing all these lights illuminated can be pretty alarming, but it is essential to remember that they are there for a reason – to alert you of potential problems with your engine.
If you see the warning light on your diesel vehicle, it is important to take action as soon as possible. The DPF (Diesel Particulate Filter) warning lamp indicates that the filter needs to be regenerated to clear any blockage.
Driving at 40mph or more for 10 minutes should prompt the DPF to go into ‘regeneration’ mode and burn off any soot that has built up. This will allow the DPF to enter regeneration mode and burn off any soot built up in the filter.
This will help keep your engine running smoothly and reduce the risk of further damage. It is also important to check your handbook for information about what the warning light looks like on your specific vehicle model.
How to Prevent Dpf Problems in The First Place
When buying a car, it is essential to consider the kind of mileage you do. If most of your miles involve short journeys or sitting in stop-start traffic where the car never really gets going, then petrol is better than diesel.
This is because diesel cars are generally more expensive than petrol and because diesel is pricier at the pumps too, you don’t see any payback from a diesel car’s improved economy unless you do a healthy annual mileage.
Normal regeneration is vital for keeping a vehicle running efficiently and reducing emissions. It involves burning off soot and other particles that have built up in the exhaust system, which can cause problems with the engine if left unchecked. Unfortunately, several factors can prevent normal regeneration from taking place.
Frequent short journeys where the engine doesn’t get hot enough to burn off the soot can be a major problem. The wrong engine oil can also prevent regeneration, as it may not be able to cope with the high temperatures required for burning off the soot.
A problem with the fuel system or Exhaust Gas Recirculation (EGR) can also cause excess soot to build up, preventing regeneration.
Also, suppose a warning light on the dashboard or a diagnostic trouble code is stored in the engine management system. In that case, this could indicate an issue that needs to be addressed before regeneration occurs.
Finally, going over the recommended service interval without getting your car serviced could mean that vital components such as filters become clogged up and unable to perform their job correctly, preventing normal regeneration. If your vehicle uses Eolys™ additive, then you should also check that there is enough in your
It is also important to remember that regular maintenance can help prevent problems in the first place. Regular oil changes and tune-ups can help keep your car running smoothly and efficiently for many years.
Additionally, checking tire pressure regularly and replacing worn tires can help improve fuel efficiency and reduce wear and tear on other vehicle parts. These steps will ensure your car runs properly and safely for many years.
When Should You Clean Your DPF?
On average, we recommend that the DPF be cleaned every 75,000 miles (120,000 kilometers) or once a year, whichever comes first. This is much sooner than most Original Equipment Manufacturers (OEMs) recommend, but being proactive with maintenance will help you catch upcoming engine issues quicker and prolong the life of your DPF.
The only exception is if an active regeneration process is built into your system, which can oxidize soot and convert it to ash without manual cleaning. In this case, you may not need to clean your DPF as often as recommended.
Should You Try and Clean Your DPF Yourself?
When cleaning your diesel particulate filter (DPF), it is not recommended to try it yourself. The DPF is a complex piece of equipment that requires specialized knowledge and tools to clean properly. A professional DPF cleaning facility has the necessary staff, equipment, and disposal methods to clean your DPF correctly and safely.
When Should You Replace Your DPF?
Replacing a diesel particulate filter (DPF) should not be taken lightly. If the DPF is hardened with ash and soot to the point that it cannot be cleaned, it must be replaced. This isn’t the only reason for replacement, however. High heat can also damage a DPF, leading to cracks in its structure. In this case, immediate replacement is necessary.
Unfortunately, buying a new DPF can be expensive; they range from $2,000 (sometimes less on sale) to $10,000 or more, depending on the truck and engine for which the diesel particulate filter is designed.
The Causes of Dpf Failure
Short journeys at low speeds primarily cause blocked diesel particulate filters. The filter does not get hot enough to burn off the accumulating soot, leading to a blockage.
Car makers often recommend that city-bound short-hop drivers choose a petrol car instead of a diesel. Poor servicing can also lead to DPF failure, as can using the wrong type of oil or performance modifications.
Low-quality fuel and running the car frequently on a low fuel level can also damage a diesel particulate filter, as these conditions prevent it from regenerating itself properly.
It is essential to ensure your car is serviced regularly and with the right type of oil to keep your diesel particulate filter working correctly. If you drive short distances at low speeds, occasionally take longer trips so your DPF can regenerate itself and clear out accumulated soot.
Also, ensure you use good quality fuel and avoid running your car on a low fuel level if possible. These steps will help keep your diesel particulate filter functioning properly for miles ahead.
The Symptoms of A Blocked Dpf
When diagnosing a blocked DPF, several tell-tale signs can help you identify the problem. One of the most common symptoms is increased exhaust smoke from your vehicle.
If your car emits more black or grey smoke than usual, this could be a sign that your DPF is clogged. Additionally, if you experience decreased power and acceleration when driving, this could indicate a blocked DPF.
Another symptom of a blocked DPF has increased fuel consumption. As the filter becomes clogged, it restricts the flow of exhaust gases and reduces engine efficiency. Your engine must work harder to produce the same power, resulting in higher fuel consumption.
You may also notice an engine temperature increase and an illuminated warning light on your dashboard, indicating something is wrong with your vehicle’s emissions system. If any of these symptoms are present, it’s essential to have your car inspected by a qualified mechanic as soon as possible to prevent further damage.
Warning Light on Your Dashboard
It is important never to ignore a warning light, especially regarding the DPF filter. If you get a warning light that the filter is blocked, it can be cleared by driving for 10 minutes at speeds over 40mph.
This will complete an active regeneration cycle and clear the warning light. However, if you ignore this warning and keep driving in a slow, stop/start pattern, soot will build up in the filter until your car goes into ‘restricted performance mode’ to prevent damage.
In extreme cases where the filter has been ignored for too long, driving at speed alone won’t be enough. You’ll have to get a dealer to do a manual or ‘forced’ filter regeneration, costing at least £1000 plus labor.
It is much better to take care of warning lights as soon as possible rather than wait until it becomes an expensive problem. Ignoring these warnings could lead to severe damage and costly repairs that could have been avoided with proper maintenance.
Increased Fuel Consumption and Reduced Engine Power
The rapid increase in fuel consumption is a telltale sign of diesel particulate filter (DPF) failure. The DPF is an essential component of the vehicle’s engine, as it traps soot particles and prevents them from entering the atmosphere.
When the DPF becomes clogged, exhaust gasses cannot escape the engine as quickly as they should. This accumulation of exhaust gasses affects the engine’s overall performance, reducing power output.
Drivers may attempt to compensate for this loss of power by pressing down on the accelerator pedal, but this tactic will not yield any results. Instead, drivers should take their vehicles to a mechanic for a proper diagnosis and repair. In some cases, a simple cleaning or replacement of the DPF may be all that is needed to restore average fuel consumption and engine power levels.
The Engine Won’t Start
When your engine doesn’t start, it can be a frustrating experience. The most common cause of this issue is the accumulation of exhaust gasses in the combustion chamber. This prevents the engine from starting and will keep refusing to start until the pressure is lowered.
While this may seem bad, it’s your vehicle’s way of protecting itself from fatal damage to your engine and diesel particulate filter.
If you are in this situation, you must consult a mechanic immediately. They can diagnose the problem and recommend the best action to get your vehicle back up and running.
In some cases, they may even be able to reset the pressure in the combustion chamber without replacing parts or performing significant repairs. Regardless, it’s essential to let a professional mechanic look at your vehicle to get back on the road safely and quickly.
Turbocharger Problems
Turbochargers are an important part of a vehicle’s engine, as they help increase its power output and efficiency. However, if there is a problem with the turbocharger, it can cause a variety of issues. One common issue is caused by a blocked diesel particulate filter (DPF).
This causes gas to build up in the engine, which has nowhere to go and starts leaking from the turbocharger. This can lead to oil leaks and reduce the overall efficiency of the turbocharger.
To prevent these problems from occurring, it is essential to check and maintain your vehicle’s DPF regularly. If you notice any signs of leakage or reduced performance from your turbocharger, it is best to take your car to a mechanic for inspection as soon as possible. Regular maintenance and care can help ensure your turbocharger remains in good working condition for years.
How the Choice of Engine Oil Impacts Your Dpf
The choice of engine oil is an important factor in the maintenance and longevity of a diesel particulate filter (DPF). Traditional engine oils contain metallic additives that act as powerful anti-friction, anti-wear, and detergent agents.
However, these additives can result in the creation and accumulation of ash which blocks the substrate wall and prevents the uninterrupted flow of exhaust gasses. This harms DPFs and three-way catalytic converters, leading to their eventual failure.
To avoid this problem, it is essential to use low-SAPS engine oils for cars fitted with a DPF. These oils are specifically designed for diesel engines and do not contain metallic additives that can damage the filter.
They also provide superior lubrication performance while reducing emissions from diesel engines. Low-SAPS engine oils are available in synthetic and mineral varieties, so you can choose one according to your needs and budget. Ultimately, using the correct engine oil will help ensure your DPF remains in good condition for extended periods.
Do I Need a Diesel Particulate Filter to Pass the Mot?
A diesel particulate filter (DPF) is an integral part of a car’s emissions system, and it has been a mandatory check during the MOT test since February 2014. If the DPF has been removed from the car, it will fail its MOT. This is because the filter helps to reduce harmful emissions from diesel engines, and its absence can cause severe environmental damage.
It is, therefore, essential that all cars have a functioning DPF to pass their MOT. If your car does not have one, you must get one fitted before taking it for its MOT test. It is also essential to ensure that any repairs or replacements are carried out by a qualified mechanic who can guarantee that the work meets all necessary safety and environmental standards.
Removing the DPF can also cause the warning light to glow on the dashboard, another reason a car would fail its MOT. The warning light indicates something is wrong with the vehicle, and no dashboard warning lights should remain on during the test.
It’s important to ensure that your car has a functioning DPF before taking it for an MOT, as this could save you time and money in repairs or replacements if it fails due to this issue.
Use A Good Quality Oil
The choice of engine oil is an essential factor in the maintenance and performance of a diesel particulate filter (DPF). Traditional engine oils contain metallic additives that are effective as anti-friction, anti-wear, and detergent agents.
However, these additives can lead to the creation and accumulation of ash, which blocks the substrate wall and prevents the uninterrupted flow of exhaust gasses. This can cause significant damage to both the DPF and three-way catalytic converters.
To ensure that your DPF remains in good condition, it is essential to use low-SAPS engine oils designed explicitly for DPFs. These oils are formulated with fewer metallic additives that reduce ash production while providing adequate protection against wear and tear.
DPFs require a special low-ash oil, and there are several grades available. Make sure you select the right one for your car.
Additionally, they help keep the filter clean by preventing soot buildup on its walls. Using the right engine oil for your car fitted with a DPF can significantly extend its life expectancy.
Another way that using the wrong oil can harm your DPF is through a leaky turbo oil seal. If this happens, it will allow too much oil into the exhaust system, clogging up the DPF and causing permanent damage.
To avoid this problem, stick to regular service intervals and use only high-quality oils specifically designed for your vehicle. Doing so will help keep your car running smoothly and protect its components from unnecessary wear and tear.
What Other Costs Are There With Diesel Cars?
When it comes to running a diesel car, some additional costs need to be taken into consideration. One is the cost of topping up the AdBlue or Diesel Exhaust Fluid (DEF). This liquid is injected into the exhaust gas to reduce nitrogen oxide (NOx) emissions and create a more environmentally friendly output.
If you own a Jaguar or Land Rover, your car automatically tells you when to top up your DEF tank. The car’s display will show an amber icon with a message advising how many liters of DEF should be added.
It’s important to note that topping up your DEF tank benefits the environment and your wallet. By reducing NOx emissions, you can save money on fuel costs and reduce wear and tear on your engine components. Additionally, if you keep up with regular maintenance and top-ups of AdBlue/DEF, it could help extend the life of your vehicle and save you money in the long run.