Diesel cars, used mainly for city driving, can mysteriously break down.
The Diesel Particulate Filter (DPF) – a ‘trap’ to catch soot in the exhaust – may be the culprit, says car leasing company HSBC Vehicle Finance.
DPF exhaust filters strangle city diesels to a £1000 stop
The cost of a replacement can be up to £1000.
A DPF is fitted to many diesels to reduce the amount of soot emitted in the exhaust.
A DPF usually collects this soot and then burns it off at high temperatures. This is called regeneration.
However, if a diesel with a DPF is used mainly in the city, it may never reach the temperature to ‘regenerate’. The soot builds up and eventually chokes the exhaust.
“We’re seeing a growing number of vehicle failures. These are due to drivers being unaware of the need to keep filters in good working order,” commented Peter Hollinshead, head of HSBC Vehicle Finance.
“It is always important to follow the manufacturer’s instructions for filter regeneration. If this is not done, the driver will experience a fall off in performance and eventual total engine failure,” he warned.
HSBC suggests owners of diesels fitted with a DPF ensure their car gets a good run on a motorway once a month. By doing this the exhaust temperature can reach a high enough temperature for DPF regeneration to occur.
For cars with a very high sixth gear, occasional harder driving in lower gears may be needed to generate the heat for burn off.
Roger Williams, head of major fleets and leasing at AA Business Services, commented: “Businesses need to be aware of the limitations and potential problems with their fleet cars. Any business, small or large should view car maintenance – including the maintenance of filters – a top priority to avoid breakdown.”
Further information on DPF filters
- If you want to know more, the AA has a good explanation of the issues surrounding diesel particulate filter failure
- Or you can read our article on The Law and maintenance
