A clogged DPF is a well-known problem with the Citroën Berlingo diesel. Short journeys in particular and urban use mean the diesel particulate filter (DPF) cannot regenerate properly, causing soot to build up. This leads to loss of power, warning lights and sometimes even limp mode. Do you know exactly what is going on and how to prevent it?
Why does the DPF get blocked on the Berlingo?
The DPF traps soot particles from the exhaust gases. These particles are then burnt off during a regeneration cycle, where the system heats the filter to a high temperature. On the Citroen Berlingo this process often goes wrong because the engine does not get warm enough. Those who mainly make short trips give the system too little time to complete the regeneration.
The most common causes are short and gentle city driving, lots of idling and low speeds. In addition, faulty sensors or problems with the additive system can cause regenerations to fail. On some Berlingos with PSA diesel engines an Eolys system (an additive system for the DPF) also plays a role; it supports regeneration but causes problems when the level is low or the pump is defective.
Underlaying engine faults also contribute to a blocked filter. Think of a dirty EGR valve (exhaust gas recirculation valve) or turbo and injection issues that cause incomplete combustion. This produces extra soot that fills the DPF more quickly.
‘ In severe cases the engine switches to limp mode, where the maximum speed is limited. ’
Symptoms of a blocked DPF
A clogged DPF gives off clear signals. The dashboard often shows a DPF warning light or an engine fault light. Some Berlingos even display a message that the filter is full, overloaded or worn. Besides these warnings you will also notice an immediate change in the way the car drives.
Loss of power is a very common complaint. The car no longer pulls as it should and responds sluggishly to the accelerator. In severe cases the engine switches to limp mode, where the maximum speed is limited. This happens to prevent further damage.
Fuel consumption also rises noticeably when the DPF becomes blocked. The engine has to work harder and tries to regenerate more often, which uses extra diesel. Other signs are an engine that runs unevenly, a cooling fan that keeps running for a long time after switching off and an increased idle speed during regeneration attempts.
How do you clean the DPF on your Berlingo?
Cleaning starts with reading out the fault codes. This gives insight into the soot loading, the pressure difference across the filter and any sensor faults. On this basis you can determine whether regeneration is still possible or whether professional cleaning is needed.
A forced regeneration via diagnostic equipment can help if the filter is not too full. The engine is then brought up to temperature under controlled conditions to burn off the soot. This method only works if the soot loading is still within acceptable limits and the system is functioning correctly.
In the case of severe blockage professional cleaning is required. Specialist companies use chemical flushing agents or thermal cleaning, in which the filter is heated in an oven. This also removes stubborn ash and soot deposits. Note: after cleaning the system must be reset in the diagnostic equipment, otherwise fault messages will keep coming back.
Some owners opt for a driving style that encourages natural regeneration. Drive for at least 20 to 30 minutes on motorways or country roads at a constant engine speed between 2,000 and 3,000 revolutions per minute. Keep the engine at operating temperature and avoid frequent braking or stopping. This gives the system the chance to complete the regeneration.
Prevent DPF problems with these driving tips
Prevention is more effective than intervening afterwards. Adjust your driving pattern by regularly making longer trips in which the engine gets properly warm. A journey of at least half an hour at higher speeds prevents soot from building up.
Avoid excessive idling. A cold engine produces more soot and the DPF has no chance to regenerate. Start the engine, drive off gently and let it warm up while driving instead of letting it warm up while stationary.
Where possible fill up with good quality diesel at reliable filling stations. Poor fuel contains more contaminants that contribute to soot formation. Good quality diesel burns more cleanly and reduces the load on the filter.
Stick to the service schedule and have fault codes read out quickly when a warning light appears. The earlier you detect an incipient blockage, the easier it is to solve. Never drive around for long with a lit DPF warning light; this can cause permanent damage.
‘ Replacement is expensive, but sometimes unavoidable. ’
When is DPF replacement necessary?
Not every blocked filter can be cleaned. If the DPF has become clogged too often or there is structural damage, replacement is the only option. When the ash loading has become too high, cleaning no longer helps because ash cannot be burnt.
A diagnosis will show whether replacement is needed. Mechanics look at the total soot and ash loading, the pressure difference and the condition of the filter material. In the case of cracks or melted sections, replacement is unavoidable.
Replacement is expensive, but sometimes unavoidable. A new original DPF for the Berlingo costs from several hundred up to well over a thousand euros, depending on the engine type. Exchange repair or refurbished filters are cheaper alternatives, but always check the warranty conditions.
After replacement it is important to reset the system correctly. Without a reset the onboard computer will not recognise the new filter and fault messages will continue to appear. On Berlingos with additive systems, the reservoir level and counter must also be updated.
Pay attention to the DPF additive system on older Berlingos
Some Berlingos with PSA diesel engines use an additive that supports regeneration. This system injects a small amount of fluid into the fuel tank to lower the combustion temperature of soot. This helps the DPF to regenerate more efficiently.
The reservoir for this additive runs empty over time. When the level becomes too low, regeneration can no longer take place properly and soot builds up more quickly. A defective additive pump or blocked line causes the same problem.
Have the additive level checked during routine servicing. Topping up is done at a dealer or specialist workshop, because the system often has to be reset after refilling. Do not ignore messages about the additive system; this will help prevent expensive DPF problems later.
Also check sensors and other engine systems
A clogged DPF is often not a problem on its own. Faulty sensors can transmit incorrect values, making the onboard computer think the filter is blocked when it is not. Pressure sensors and temperature sensors are sensitive to contamination and wear.
The EGR valve also plays a role. A dirty or faulty EGR valve leads to incomplete combustion and additional soot production. This significantly speeds up the blocking of the DPF. Have the EGR checked and cleaned during servicing.
Problems with the turbo or injection system also lead to more soot. A turbo that is not working properly disrupts the airflow and combustion balance. Leaking or worn injectors (injector nozzles) cause incomplete combustion. Solve these problems before you clean or replace the DPF, otherwise the problem will quickly return.
‘ Resetting fault codes without diagnosis and repair ultimately leads to more serious damage and higher costs. ’
Practical experiences from Berlingo owners
Many Berlingo drivers report that the problem comes back after cleaning if their driving pattern does not change. Those who continue to make mainly short trips will have a blocked filter again within a few months. Adjusting your driving behaviour is therefore at least as important as technical measures.
Owners who regularly make longer trips have significantly fewer problems. In practice, a half-hour motorway drive once a week proves effective in allowing regenerations to succeed and keeping the filter clean.
Some owners have experience with resetting fault codes without addressing the underlying cause. This masks the problem temporarily but does not solve anything. Resetting fault codes without diagnosis and repair ultimately leads to more serious damage and higher costs.
Discover more about your Berlingo on Carnews
DPF problems are just one aspect of maintaining your Citroën Berlingo. On the Carnews website you will find extensive information on many more topics relating to this versatile car. From engine issues to service schedules and practical tips for everyday use. Discover what other owners experience and get the most out of your Berlingo by making sure you are well informed.
Frequently asked questions
Typical symptoms of a blocked DPF on a Berlingo are a DPF or engine fault light on the dashboard, clear loss of power, higher fuel consumption and sometimes limp mode. You may also notice that the engine pulls unevenly, the idle speed is temporarily higher or that the cooling fan keeps running for a long time. Early recognition starts with taking warning lights and noticeable loss of power seriously and having them read out straight away with diagnostic equipment. It also helps to make longer journeys regularly so that the filter can complete a full regeneration and early blockage has less of a chance.
Drive at least once a week for 20–30 minutes at motorway speed so that the engine and exhaust really get up to temperature, preferably at a slightly higher engine speed (for example 2,500–3,000 rpm in a lower gear) to allow good regeneration of the DPF. Avoid consistently only making short urban journeys and a lot of idling, because then the DPF has no chance to burn itself clean. Use good quality diesel and, if warning lights or DPF messages appear, quickly have the fault codes and the condition of the additive, sensors and pressure difference checked. After servicing or any cleaning, always have the DPF and additive system correctly reset using diagnostic equipment.
You can have the DPF forced to regenerate via diagnostic equipment or by making a long journey at motorway speed; this is inexpensive and keeps the original filter, but only works if the filter is not yet heavily blocked or worn. Professional DPF cleaning (removal and flushing/cleaning) restores the flow and is cheaper than a new filter, but requires removal and the problem can return if the cause (driving style, engine fault, additive) remains. Chemical or on-car cleaning products are relatively cheap and quick, but give mixed results and may be insufficient in the case of severe blockage. Replacement with a new original or good quality replacement DPF offers the most durable solution and also resolves a “worn out” filter, but is by far the most expensive option and then requires a correct software reset and a check of the underlying cause.
A blocked DPF increases the back pressure in the exhaust, meaning the engine has to work harder and fuel consumption can noticeably rise. You will often notice this as less pulling power, poorer acceleration and sometimes even limp mode or a limited top speed. The engine may also run more roughly and attempt to regenerate more frequently, which drives up consumption even further. If you continue to drive like this, it can eventually put extra strain on other components (such as the turbo and EGR).