Hopefully our FAQ section has answered some of the questions you may have about diesel particulate filters, however, if you would like more information, we have the following guide help you understand more about your Subaru
Ever since 2009, the Euro 5 standard has been enforced, a rule which ensures all new diesel Subaru must have particulate filters fitted.
These pieces of equipment were introduced in an effort to reduce the particle and soot emissions from diesel engines. Diesel Particulate filters (DPF) trap soot before it blows out of an exhaust and like any filter, it requires cleaning in order to maintain performance.
Fortunately the filter itself has self-cleaning capabilities known as regeneration.
There are two types of regeneration which can be carried out on your Subaru.
This process happens automatically while the exhaust is at a high temperature which will usually occur when you are driving down a motorway or quickly down an A-road. However, as many vehicles aren’t always being driven at high speeds, an alternative system for regeneration exists.
This method of cleaning the DFP is controlled by an engine management computer and happens automatically when the filter reaches 45% of its limit. The process is initiated by the fuel injection being increased which makes the exhaust heat up and therefore clear the filter. However, if your drive is a short one and the process tries to initiate, it will not be able to properly clear the filter, in this eventuality, the warning light in your car will come on.
A drive of about ten minutes at a speed of around 40mph should be adequate for the process to be successful.
Here are the signs of automatic regeneration
Cooling fans running
Increased idle speed
Deactivation of automatic stop/start
A slight increase in fuel consumption
A hot and strong smell emitting from the exhaust
The note of the engine changing
However if the regeneration is unsuccessful, the fuel which is earmarked to burnt, will have to drain into the sump.
This will result in the oil quality in your Subaru getting worst and its level will rise.
That is why it is important that you keep an eye on your oil levels at all times as any drops, change in viscosity or mixing with other agents such as lubricant or water, can cause serious damage.
You should have an automatic sensor in your Subaru to warn you of any impending damage, which should not be ignored as the entire engine will be at risk.
If you do ignore the DPF light the filter will reach a point where it cannot function and other warning lights will come on as other parts of the engine are effected. If the soot level reached 70-75% you have no choice but to take the car to a garage and have it manually refreshed.
What prevents automation regeneration?
Lots of small journeys
Wrong oil type
Gas recirculation malfunction
Constant low fuel level
Low additive levels
If these issues are effecting your Subaru it is almost certain that you will need your filter replacing which is likely to cost upwards of £1000 including diagnostic and labour time.
And if you were thinking of saving all of that time and money by removing the filter completely, think again, it’s illegal to remove the DPF.
The Department for Transport states that it is an offence to remove the filter or modify the piece of equipment in a way which would result in the vehicle failing air pollutant emission standards. Breaking the law will result in the vehicle not being road worthy so if you are ever offered to have your filter removed, make sure to keep this in mind.
Every MOT now includes a check for the DPF and a smoke test from the exhaust so there is very little chance of getting away with removing the filter.
If you need to have the filter regenerated manually, you must take your vehicle to a trained professional immediately. They will initiate a process where the exhaust is heated up to a point where regeneration happens and soot is cleared from the filter.
Finding a mechanic you can trust to do a good job and charge a fair price is not always easy. We work with a network of 8,000 mechanics and garages across the UK so we can find a competitive Diesel particulate filter repair deal for you.
To find the best service available in Bethnal Green:
You can then compare the quotes and read reviews from previous customers to find the best deal in Bethnal Green, before booking the DPF repair online.
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