Seems like you need to drive at 50mph for 20-30mins for it to "clean" its exhaust.
http://www.bbc.co.uk/blogs/watchdog/2011/10/diesel_particulate_filters.html
http://www.bbc.co.uk/blogs/watchdog/2011/10/diesel_particulate_filters.html
Is your diesel filter out of kilter?
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Post categories: Cars and transport
Elham Rizi | 18:45 UK time, Thursday, 20 October 2011
Whether it's dropping the kids off at school, commuting to work or doing the weekly shop, a city car seems to be the perfect solution for the urban driver.
And they come with some tempting incentives too like being low on emissions, low on tax - and if you chose a diesel car, you could save money on fuel consumption. But did you know that nearly all new diesel cars are fitted with an eco-friendly car component which is leaving some motorists with huge bills to pay? Chris Hollins investigates.
The part in question is called a Diesel Particulate Filter or DPF. It's fitted to the exhaust to trap the soot and reduce emissions. The part was introduced to bring cars in line with new EU green emissions rules. But if you use your car solely for city driving then you could be in trouble.
The part usually cleans itself when the engine runs at high speeds - a process called regeneration. If this hasn't happened for a while, a warning light indicates that the filter is getting blocked. It must then be cleared by driving the car at high revs for a sustained period of time. This is easily done on the open road but is much more difficult to do around town.
Watchdog has received over two hundred complaints about problems concerning diesel particulate filters. And it's a problem that affects diesel cars made by most manufacturers. Some drivers have had to pay hundreds of pounds to have their filters cleared whilst one customer needed a replacement costing over £1000.
Damon Noad bought a brand new diesel Fiat 500 as a city run-around in 2009 from a local dealership. Within a year Damon noticed a warning light on the dashboard and soon learnt that his little Fiat had a big problem. He learnt that the car was fitted with a DPF and that he would need to take his car out regularly for around 20 minutes and drive constantly for 40-50mph for the vehicle to function properly. Fiat do mention this in their manual but Damon says he wasn't told about it when he bought the car, nor was he told that the car was not suitable for city driving only.
And it's not just the diesel Fiat 500s that have the filter. Wayne Brunton found he had problems when he purchased a so called 'Urbanproof' Nissan Qashqai. Buying the vehicle second hand, Wayne explained that it would mainly be used for day to day commuting as well as pulling his caravan occasionally. Five months after purchase, the amber filter light on the dashboard came on. Wayne followed the guidance in the manual and took his car onto a road where he could drive above 50mph for 30 minutes. It resolved the problem in the short term but a month a later the light came on again, this time accompanied with the engine management light. Wayne took the car into his local dealership for investigation. The filter had to be regenerated, despite the car being under warranty; Wayne was charged nearly £250 because the previous owner had already claimed for the filter. Nissan have agreed to refund Wayne but only on this occasion.
Tim Shallcross from the Institute of Advanced Motorists says that manufacturers make sure dealers are asking questions about buyers driving habits and the care of the car when customers purchase the vehicle. They can do this by asking searching questions and if customers say they are only going to use the vehicle for urban driving, then they may not benefit from a vehicle fitted with DPF; consequently, dealers should be advising them to go for a petrol car instead.
Tim says that in most cases the regeneration process is activated by the exhaust pipe getting hot which is achieved by getting the engine speed up. The best way to ensure a regeneration is successful, is to maintain the engine speed at 2500 rpm for at least 15-20 minutes. Driving along a dual carriage way, for example, at 50 mph and stopping for roundabouts won't be achieve a successful regeneration because a constant high engine speed needs to be maintained for a successful regeneration. He also adds that manufacturers should be advising drivers to drive for a sustained period of time and focus on getting their revs per minute up instead of focusing on the speed.
Fiat Statement:
Fiat does its utmost to ensure our franchised dealer network and their salesmen have full access to training programmes that enable them to qualify the needs of potential customers. This training is supported by regular 'mystery shopper' exercises designed to ensure the training is put into practice to benefit customers.
We would point out that for both prospective purchasers and owners of Fiat vehicles, we make available documents that can be downloaded free of charge from our web site. There is a specific DPF supplement that deals exclusively with the functionality and characteristics of the Diesel Particulate Filter, and details the actions required should the DPF warning light illuminate continually. This information is also included within the Owners Handbook which is again available to download free of charge.
It also details the actions required if the warning light does come on. In this instance, we advise that the optimum conditions for DPF regeneration are to travel at a speed higher than 38mph at approximately 1800rpm for a period of 15 minutes. Clearly, this speed can safely be achieved on many UK roads, without the need to take the car on to a motorway.
At the point of sale our new car brochures contain full details regarding the fitment of a DPF and the supplement and handbook, mentioned above, are provided in hard copy within the customer literature pack supplied by the salesman during the new vehicle handover. Therefore in terms of providing information to our customers, we believe these provisions to be comprehensive.
With regard to the matter of DPF regeneration, the statement given by your expert is of a general nature and is not applicable to the Fiat 500. For your information, the optimum regeneration conditions required for the Fiat 500 are not as exacting as those quoted by your expert and we believe, do not require a change in driving style and are typical of the general use a vehicle will undergo during the ownership period.
We don't comment on individual cases, however we understand that the complaint you are referring to does not allege a fault with the vehicle as such.
We would ask you to note that we have never directly advertised the Fiat 500 diesel version as a city car although the Fiat 500 has received many awards including those in the category City Car of the Year. These categories are created by the organisations or publications that produce the awards and while we are always pleased to receive accolades, we would point out that the Fiat 500 is designed to be used in all driving environments and not just urban areas.
Finally, with regard to Fiat 500 customers' choice of engine option, in the period 2009 to YTD 2011, less than 2% of our customers chose diesel engines.
In closing we would remind all of our customers that Fiat can be contacted on 0080034280000 or by visiting www.fiat.co.uk .
NISSAN DPF STATEMENT
Particulate filters are now fitted to car makers' diesel engines in order to help comply with emissions laws. Most owners are unaware they even exist as they operate automatically when the exhaust temperature reaches a certain level, usually at motorway speeds.
Petrol engined cars in the Nissan range do not use a DPF.
Because of the way most DPFs work, they may not be ideal for cars which are used exclusively for short, low speed journeys.
All Nissan sales staff are trained to help customers make the right choice of engine type for their circumstances. They would recommend one of Nissan's many advanced petrol or electric vehicles for buyers who use their car for short journeys only.
To further assist customers make an informed choice, explanations of how DPFs work are clearly printed in sales literature of both the printed and online eBrochures. Below is an example from the Qashqai brochure:
"The 1.5dCi, 1.6dCi and 2.0dCi engines fitted to QASHQAI include a diesel particulate filter (DPF) to reduce emissions and help protect the environment. The functionality of a DPF may not be suitable for all customers. If your journeys are predominantly urban or low speed, a model without a DPF may be a more suitable alternative."
Owners will also find clear explanations of the DPF maintenance programme printed in the car's manual.
If the car has been unable to regenerate the DPF automatically, a warning light on the instrument panel indicates that the owner should go for a longer drive to create the necessary conditions for the exhaust to reach a higher temperature. If this is carried out correctly a visit to the dealer will be unnecessary.
If an owner still finds they need DPF regeneration at the dealer, Nissan will cover the first instance under warranty and will again seek to educate the owner about the procedure so further work is unnecessary.
When these instructions are followed and the car properly maintained, the DPF should continue to help drivers protect the environment easily and effectively.
SMMT statement:
Diesel models account for around 50% of the overall new car market and nearly 120,000 small, diesel powered cars have been sold so far this year. The majority of motorists are happy with the performance and economy they achieve so it is extremely disappointing when a customer has a bad experience. We work hard to deliver a consistently high quality of service.
Vehicle manufacturers provide extensive information to customers in the form of online resources, advice stickers on the vehicle and dedicated information sheets provided at the point of sale and on their websites to advise buyers before they purchase a new car. This detail is reinforced through the franchise dealer network, whose salespeople are trained to help motorists choose and understand the most appropriate vehicle for their needs. It's important that car buyers discuss their driving habits with their dealer to make sure they get the best advice.
Normal UK driving conditions - even those found in towns and cities - are usually sufficient to allow DPFs to regenerate automatically, and most drivers would not need to do anything specific to maintain their DPF systems, but should an issue occur, drivers should follow the guidance offered in their handbook and by dealer staff to ensure trouble-free motoring.
Manufacturers are committed to continually improving standards and delivering the high levels of customer service most people rightfully expect from the industry and are constantly reviewing and updating their training to deliver a positive customer experience.
As an industry, we support Motor Codes which runs a suite of OFT-backed Codes of Practice within the motor trade and offers free consumer advice and conciliation in the event of customer concern.
