DPF Regeneration Instructions And How To Keep Your DPF Healthy!

UPDATE!!

If you came to this page because of fault/trouble codes you retrieved from a diagnostic tool you may find our iPhone/iPad or Android App useful.

Not only does it give you 'Fault Descriptions' but also gives you 
Possible Causes!! 

 Check it out on the App Store or Play Store!! 

DPF 

Your car is fitted with a DPF (Diesel Particulate Filter) and you have heard a lot of stories about expensive repair bills, regenerations and additives... So you look on the internet for how you keep your DPF healthy and how 'DPF Regeneration' is performed!! Good news.... Its not all doom and gloom when it comes to your DPF

Firstly, what is DPF regeneration?

Well to best answer that, let's take a look at what the DPF actually does.... The DPF is a particulate filter, fitted to the exhaust system on diesel cars, it is designed to trap harmful particulates in the exhaust gases. Once the amount of trapped particles otherwise known as soot loading becomes too great engine ECU senses this and carries out the DPF regeneration process.

Now we know that, we can better understand DPF regeneration.... A question I  often see is what is the point in the DPF trapping the particles if it's only going to chuck them out the exhaust during regeneration? Answer is, it does but it doesn't. What happens is the during regeneration the exhaust gets to a hot enough temperature, ideally around 600 degrees celsius, that through some clever chemistry, the harmful particles or hydrocarbons react with the catalyst inside and become less harmful particles. I'm sure we have all heard of our good friends H2O and CO2 otherwise know as water and carbon dioxide. 

So what can be done to keep your DPF clean and happy?

So it turns out, short trips and urban driving don't do your DPF and favours, only assisting in filling the DPF faster. This is because when an engine is cold it doesn't burn fuel as cleanly as when the engine is hot, another side effect is that the exhaust doesn't get hot enough for a long enough period of time to carry out the DPF regeneration. So how can you combat this. Well depending on how many short trips you do over a week or fortnight, the best thing you can do is get your car on the dual carriageway and then drive according to the following points!!

• Ensure engine is at operating temperature.
• Drive in fourth or fifth gear.
• Drive above 50 mph.
• Keep engine speed between 2000 and 3000 rpm.
• Keep going for at least 20 miles. 

As long as the above is followed, if vehicle senses that a DPF regeneration needs to be carried out it will do so automatically without the need for any diagnostic tools!!! 

 Another thing you can do, is to use either the more expensive diesels such as BP Ultimate or other premium fuels, or a good diesel additive. This is because better diesel has a higher cetane rating, the higher the cetane rating the better the combustion quality or cleaner burn, in turn not loading the DPF as much, resulting in less frequent DPF regeneration processes. A good side effect of using better diesel is better EGR (Exhaust Gas Recirculation) health and it helps to keep the engine internals cleaner.

Another step to take is to ensure servicing work is carried out at the correct time and to the correct standard. See here. What is a car service.

This is because some vehicles have an additive tank which needs filling with the correct additive as part of some service schedules.

So what actually goes wrong with your DPF. Well some common issues are...

• The pressure differential sensor can fail.
• Too many DPF regenerations have been carried out. (They have a limited lifespan).
• The DPF has become overloaded and automatic regeneration is not possible. In this case you need to force the regeneration process using suitable diagnostic equipment.
• The DPF can break apart internally. 
• The temperature sensor can fail.
• The additive tank can run empty. (If fitted).

There are other failures but these are the most common.

For some people the cost of DPF failure is too great, and in an attempt to prevent further failure they seek to remove the DPF entirely more on that here. DPF Removal.

I hope this helps in your mission to avoid large DPF repair bills! Have you had any DPF problems? Let us know in the comments!!!