Thirty years ago, driving a vehicle powered by diesel fuel typically meant driving a car or truck that habitually released plumes of black smoke and heavy emissions. Today, environmental rules have sharply reduced the problems from diesel fuel usage. One of the systems you’ll find in vehicles with a diesel engine is DPF or Diesel Particulate Filters. These filters are part of the exhaust system and trap harmful particulates from being released outside of the vehicle.
However, the filters themselves may become so saturated with particulates that they must be professionally cleaned and/or replaced. In this guide, we are going to consider diesel particulate filter costs and the ways you can have these filters replaced by an expert. Note that it is against the law to modify or remove the Diesel Particulate Filters on any vehicle, meaning professional help is required for this task.
Vehicles that use a DPF also have a catalytic converter, and they work together to reduce emissions. The latter, however, is a unit in which exhaust passes over a material that changes the gases into less harmful materials. The DPF is not a “flow-through” unit. It has a substrate through which gases are forced through various walls and where particles are deposited, allowing cleaner gases to exit the filter.
DPF has been around for more than a decade and seems to be a very confusing matter for many vehicle owners. Meant to capture around 80% of particulates and soot, the filters can become saturated. Yet, changing them right away is not necessary as they can be heated from within and burn off the clogging particles.
Described as a smart filter, it uses sensors that gauge the amount of soot blocking the filter. The sensors come before and after the DPF unit and they run automatically and are controlled by an engine management array or system. The DPF uses a process called regeneration to burn off particles and soot and there are three main forms of regeneration:
You should find out what type of regeneration your vehicle uses before searching for a DPF replacement provider. This helps you estimate the dpf cost for your car.
Passive regeneration occurs when the vehicle is at a highway speed and exhaust temperatures are their highest. It is done automatically, but if you are not driving at highway speeds, active regeneration may be used.
The ECU or Engine Control Unit tracks the level of soot and particles in the DPF. When it hits the 45% level, the ECU triggers a post-combustion fuel injection. This sends fuel into the engine to boost the temperature of the exhaust and cue the regeneration process. This is usually accompanied by an indicator on the vehicle’s dashboard, alerting a driver that DPF regeneration is occurring.
Stopping this process forces a vehicle into a reduced power mode to prevent damage to the engine, and an array of warning indicators may fire. If this happens, the forced regeneration mode is required. This is when DPF becomes a very costly affair.
Forced regeneration means a tow to a repair shop and the use of diagnostic tools and a forced process of regeneration in which the oil and oil filter are changed to prevent damage.
Although these systems are meant to offer long term operations and function, a DPF may become too heavily clogged or blocked to allow for total regeneration. At such times, it may be necessary for the filter to be removed from the vehicle and professionally cleaned. Costs to clean diesel particulate filters can be expensive, with averages running from £85 to £300. New filters may range from £1,000 to £3,500.
Most DPFs are designed to provide up to 160k kilometres, but with proper maintenance and operation, they can last much more.
A blocked DPF is going to cue the regeneration process. That means the signs of a blocked DPF may be identical to active regeneration. The key is to watch for any indicators that the process failed because that means it is necessary to get a forced regeneration. The signs are:
Burning or “hot” odours from the exhaust
The vehicle’s cooling fans will run
The idle speed is going to increase dramatically
Fuel consumption will increase slightly
The engine “note” changes
Automatic start/stop is deactivated
Panel lights may indicate oil quality/viscosity issues, soot loading indicators light, and other warning lights will illuminate
If your panel does indicate problems with the DPF regeneration process, which is usually when a restricted performance mode begins, it means that you have a DPF blocked as much as 85%. This is when professional help is required and a forced regeneration must be done.
Normal regeneration can be prevented by a long list of issues:
You drive only short journeys where the engine does not hit high enough operating temperatures
You used the wrong oil (i.e. you did not use a low Sulphur and low ash oil)
There is a failure or problem in the EGR system, fuel or inlet that has prevented combustion from occurring properly
An unrelated issue has cued a diagnostic code or warning light, and the ECU or engine management system blocks regeneration
Too little fuel prevents the regeneration (active variety) from occurring. It needs ¼ of a tank to function
You exceeded the service interval
You failed to refill the DPF additives tank (if the vehicle uses one)
You ignored warning lights
Biodiesel was used and cause rapid saturation of the DPF
How much does a diesel particulate filter cost? This can vary because there are options for cleaning and re-installation, as well as swapping a blocked filter for a full replacement. The standard prices for new filters usually begin at that £1,000 mark, though some go much higher.
There is also the matter of an hourly rate paid to the mechanic or service centre. The national average in the UK ranges from £40 to £120 per hour, and this varies based on the mechanic’s level of expertise and skill. Few offer DPF as a flat task and instead charge based on such factors as:
Make and model
Whether you used an OEM or aftermarket DPF
Range of services in addition to the DPF replacement
Whether the filter can be cleaned and reinstalled
There are issues with the engine timing, ignition, fuel mixture, and so on
A full vehicle history check should be done, which adds to the cost
Problems with one of the four different temperature and pressure sensors (which may need replacement)
This too will vary widely from vehicle to vehicle. The mechanic has to check the vehicle’s history in addition to looking for any reasons that a DPF is failing. They will check temperature and pressure sensors, replacing any that have filed.
They will have to remove the DPF and send it for cleaning or swap it for a functional unit. They must then reset the engine management system or ECU and do a forced regeneration to allow the vehicle’s systems to recognize a new DPF. The appropriate oil must be used, and a new fitment kit may be needed for a brand-new DPF.
Hopefully, you now understand the importance of ensuring your DPF functions properly and that you pay attention to any warning signs of trouble. If you have been knocked into the lower performance mode and need a forced regeneration, or you think it is time to have a new DPF installed, you can find providers with an Airtasker listing.
Be sure you include the information below to get the most qualified mechanic and don’t base your choice on pricing. Look at their level of experience in DPF replacement, as well as the DPF replacement cost listed.
We suggest you include the following details:
The time frame required (emergency, longer amount of time available, etc.)
Budget (the amount you have for the project)
Your location and if you anticipate any issues or challenges posed by the location
The make, model and age of the vehicle along with notes on the status of the DPF and the ECU
The materials and parts you will provide (and ask for a quote on them if you want to compare your options)
If you require a warranty on labour (and materials if you don’t supply them)
The more details you offer, the easier it is for a provider to give an accurate and competitive offer. Keep in mind that most will also use your listing as a guideline for when they arrive to do the work – so accuracy and honesty are key!
Many vehicle owners hire experts for the installation and purchase the replacement parts themselves. This is a good approach, but you will also want to consult experts to be sure the right parts have been purchased. Here are a few examples of recent Airtasker listings for DPF replacement:
Just as it sounds, this is the illegal process of removing the DPF and taking steps to replace it with other components. However, this often means four-figure repair bills or more and can even result in legal fines. Deleting the gear means allowing particulates and soot into the environment, which the DPFs aim to eliminate. Deleting a DPF also prevents the vehicle from passing any emissions inspections or MOTs.
The vehicle drops into that restricted performance mode and begins to operate in a rather sluggish manner. Warning lights usually illuminate, too, and serious damages occur. For example, a blocked DPF that is ignored can also result in an owner finding that the turbo has failed and is now in need of replacement along with the DPF.
The typical rate for a timing belt replacement is around £210 to £620, which is far better than the £1000 that may be needed if the belt breaks and damages other components.