Can a Blocked DPF Damage Your Engine?

Can a Blocked DPF Damage Your Engine?

All modern diesel vehicles are fitted with Diesel Particulate Filters (DPF) as standard, designed to reduce the dangerous emissions these vehicles release. While these filters perform a valuable (and legally required) task for diesel drivers, they can become blocked over time, which seriously harms your vehicle’s performance.

Because manufacturers fit DPFs to diesel vehicles’ exhaust systems, a blocked filter will restrict airflow, eventually causing severe damage to your engine. Fortunately, many garages offer DPF cleaning in the UK, allowing you to improve the performance of your car’s engine and save you a lot of trouble in the future.

Symptoms of a blocked DPF

Loss of strength in your car

As a functioning DPF is vital for a functioning exhaust system, blockages can have knock-on effects that cause your engine to perform poorly. If your engine cannot easily vent exhaust because of a blocked DPF, then it will struggle to cycle, reducing the power output and acceleration of your vehicle in extreme cases.

Strange engine smell

Because blocked DPFs can block your whole exhaust, the fumes may build up and start to seep into the car, causing unpleasant odours and increased risk of illness over time. In addition to being unpleasant for everyone in the vehicle, the smell of exhaust fumes in your car is a serious cause for concern and a major sign that your DPF is malfunctioning.

Your engine is harder to operate

Blocked DPFs cause increased pressure within your engine and exhaust system, which means that your engine may be harder to operate. In extreme cases, you may be unable to start your engine, which might be for the best, since it means you will have to seek mechanical assistance or DPF cleaning in the UK right away.

Issues with your turbocharger

Because turbochargers work by increasing the pressure inside your engine above normal levels, any blockages in your system can cause severe damage to the turbocharger. If you have a turbocharger and a blocked DPF, then your engine may be pressurised to dangerous levels, putting you at risk of gas and oil leaks.

Quicker burning of fuel

If your DPF is blocked, your engine will have to work harder to expel exhaust gases, reducing available power and increasing fuel consumption. To bring your engine efficiency back to normal levels, you will need to clean your DPF filter, so consider DPF cleaning in the UK if you notice any of these symptoms.

How to avoid DPF problems

While it’s plain to see that a blocked DPF is terrible news, you must be wondering how to avoid these problems and detect a blocked filter before it becomes a serious issue. Fortunately, modern DPF filters include active regeneration, which allows them to clean themselves under certain conditions:

When driving at high speeds for long periods (such as on the motorway), your exhaust will reach temperatures high enough to burn off some of the particulate buildup, and you won’t have to lift a finger. Unfortunately, it isn’t easy to use active regeneration when making short trips or during city centre driving, so you should still use DPF cleaning in the UK now and then to keep your diesel vehicle in good working order.

How does a blocked DPF damage the engine?

Blocked DPFs wreak havoc with the delicate balance of your engine by preventing the normal venting of gases, which causes a variety of engine issues, as described above. In addition to reduced power and fuel efficiency, a blocked filter may eventually cause a dangerous mechanical malfunction and break your engine.

DPF Filter Replacements

Even if you regularly use active regeneration and take your car for DPF cleaning in the UK, your DPF will eventually wear out and break, requiring a replacement. Unfortunately, Diesel Particulate Filters don’t come cheap and will set you back £1,000 – £2,000 on average, though reconditioned DPFs are usually much more affordable.

Things to consider about Diesel Particulate Filters

  • When replacing a DPF, you can save money by buying reconditioned parts.
  • Driving for short periods at low speed reduces the lifespan of your DPF.
  • It is illegal to drive a diesel vehicle without a DPF or remove the DPF from your car.
  • Driving with a malfunctioning DPF filter may damage your car engine.


By law, all diesel vehicles in the UK must be fitted with a DPF, and while a blocked DPF can cripple your car, there are many ways to unblock or replace it. The important thing to remember is that your DPF filter will become blocked at one point or another, so keep up the active regeneration as much as you can, and make sure you have the details of a place that offers DPF cleaning in the UK.