Q: My DPF light has come on what does this mean?
A: It depends on the Manufacturer of your car, it often means you need to keep driving until the light goes back out, if it does not go out after 20-30 minutes driving on a dual carriageway it is likely that there is a problem with regenerating and if the problem is not addressed the DPF will eventually block.
Below is an example of a physical pressure test on a Blocked DPF which is required to establish if the DPF is blocked and how severely.
Q: What Causes DPF problems?
A: There are many reasons for DPF problems but in most cases its not the Filter that is at fault, in fact more likely to be the victim of another issue which can be just a case of to many short journeys or another fault somewhere else on the car.
Q: What is the purpose of a DPF?
A: A DPF is a fine filter designed to trap Particulate matter (soot), then when a certain amount has been collected the cars management system puts it into regeneration mode, where it raises the exhaust gas to a target temperature of 550c or 450c for Peugeot engines that are fitted with an additive system, when this temperature has been reached the soot will burn and leave behind a tiny amount of ash, and the DPF is free to collect more soot again.
Q: What will happen if I don't do anything about the the DPF light not going out?
A: The warning light is there to either notify you to keep driving until a regen is achieved, or to warn you the car is not able to regenerate the filter if you keep on driving like this the filter will continue to fill with soot until exhaust gas will struggle to pass and it will become to dangerous to regenerate itself and will disable regeneration, an overfull DPF burns to hot and can melt the filter this is why the engine prevents it from regenerating when it is too full, it can also cause damage to the turbo if you continue to drive, it will eventually block to the point the engine can no longer run.
Q: My Car has high Mileage will this affect my DPF?
A: Yes a DPF is a Soot Trap which is made up from Combustible Hydrocarbons but when these are burnt of during regeneration a tiny amount of ash is left behind which is trapped in the filter eventually this builds up to a point there isn't enough room left for soot to accumulate and the filter will try to regenerate more often until the ecu rejects it based on regen frequency, your dealer will inform you that it needs a new one fitting but we have a cleaning solution for this.
Q: What is the difference between ash and soot?
A: Soot is the particulate matter the DPF is designed to trap and Ash is a mineral and metal deposit that is left behind, ash cannot be dissolved and can't be removed in the same way as soot with any solvent agents, the DPF can be removed and sent to our Head Office, where it can be deep cleaned to remove deeply embedded and compacted ash, this saves on the cost of a new filter and will also save on fuel due to reduced regeneration frequency.
Ash on a DPF Temperature Sensor
Ash in a DPF this is actually the bottom of the Catalytic Converter you can see (Light orange to Brown colour)
Q: My DPF is blocked to the point the car won't run can you still clean (unblock it)?
A: Yes there is a very high probability that we can unblock it we can still injection clean them to break down the soot to clear the DPF while still fitted to the vehicle.
Q: Have you had cases where you can not unblock a DPF?
A: Yes on rare occasions we have come across situations where it was impossible to restore a DPF, for example:
- Where a Turbocharger has previously failed and parts have fallen into and damaged the filter (this is often overlooked when a Turbo has been replaced)
- Where a DPF has been replaced with a non genuine poor quality DPF and the ceramic structure has collapsed inside.
- We have been able to unblock some non genuine DPF's only to find it is unable to regenerate because of poor quality (this just leads to constant blocking and needs replacing with a genuine part)
- Where a fault on the vehicle has caused uncontrolled high temperatures inside the DPF and has caused physical damage to it.
- Where the DPF has either reached an age or has been poorly serviced it can have a high ash accumulation this cannot be removed by any flush or injection system while on the vehicle however we can still clean these by removing the DPF and placing it in a special machine designed to remove the Ash.