Diesel cars have become increasingly popular in the UK over the past couple of decades thanks to their fuel efficiency and torque. However, diesel engines have some well-known problems that owners should be aware of. Here are some of the most common issues experienced by diesel car owners in the UK.
Diesel Particulate Filter Blockages
Modern diesel cars are fitted with a diesel particulate filter (DPF) to reduce emissions. The DPF captures and stores exhaust soot to prevent it from entering the atmosphere. Over time, this builds up and can cause a blockage. Warning lights on the dashboard will indicate if the DPF needs cleaning, which is something a DPF Cleaning Centre Birmingham can help with. If ignored, it can lead to poor performance, increased fuel consumption, or even engine damage. DPF blockages need professional cleaning or replacement which can cost over £500. Regular motorway driving of 20 minutes or more can help reduce DPF issues.
Expensive Maintenance and Repairs
In general, diesel cars have higher maintenance and repair costs compared to petrol models. Engine components such as injectors, turbochargers, and fuel pumps put extra strain on the engine and can fail over time. Replacing major engine parts often runs into the thousands. Oil and filter changes are also more expensive on diesels. Many owners report repair bills being 2-3 times higher than expected. Proper servicing and maintenance are key to minimising repair costs.
EGR Valve Problems
The exhaust gas recirculation (EGR) valve redirects exhaust gases back into the engine to reduce cylinder temperatures and NOx emissions. However, the EGR valve can get clogged over time, causing rough idling, reduced performance, and diesel particulate filter issues. Replacing the EGR valve and related components can cost £500 or more. EGR cleaning products can remove deposits and extend the valve’s life.
Turbocharger Failures
Many modern diesels have turbochargers to increase power. The turbo uses exhaust gases to spin a turbine and compress intake air. This allows more fuel and air into the engine increasing output. However, turbos spin at extremely high speeds causing wear. Bearing failures in the turbo are common on high mileage diesel cars leading to replacement costs of £800 or more. Using high-quality oil and regular servicing can help prevent premature turbo failures.
High Fuel Costs
While diesel cars offer better fuel economy than petrol models, diesel fuel is more expensive. Over the past 5 years, diesel has been around 10-15 pence per litre higher than petrol at UK filling stations. For drivers covering higher mileages, the better MPG of a diesel still makes them cheaper to run overall. But diesel costs do narrow the fuel saving benefit that diesels offer.
Common diesel issues UK owners experience include DPF blockages, expensive repairs, EGR valve failures, turbocharger problems, and rising fuel costs. However, regular servicing and maintenance can help minimise some of these issues and running costs. Most diesel problems can be avoided or mitigated if the proper preventative steps are taken by owners and regular maintenance carried out.
