DPF maintenance
Discussion
Aftermarket cleaners are snake oil.
Think about it, you are going to put ~0.5l of additive into a whole lot more fuel, pressurise it to 2000bar, inject it into a cylinder and compress it to the point where it burns.
What is going to be left to do anything productive to soot build up on a DPF?
What it needs is sustained heat, 20 plus minutes, after reaching full working temperature, at higher than normal rpm. The idea is to get some serious heat into the substrate to burn the spot and convert it into ash, which sit in the bottom of the can until such time when there is too much as and it has to be replaced.
ETA: modern diesels need to be used, and used properly, if your doing less than much less than 10-12k, it's not that simple, it depends on type of driving as well, a year the problem will come back.
Think about it, you are going to put ~0.5l of additive into a whole lot more fuel, pressurise it to 2000bar, inject it into a cylinder and compress it to the point where it burns.
What is going to be left to do anything productive to soot build up on a DPF?
What it needs is sustained heat, 20 plus minutes, after reaching full working temperature, at higher than normal rpm. The idea is to get some serious heat into the substrate to burn the spot and convert it into ash, which sit in the bottom of the can until such time when there is too much as and it has to be replaced.
ETA: modern diesels need to be used, and used properly, if your doing less than much less than 10-12k, it's not that simple, it depends on type of driving as well, a year the problem will come back.
Edited by Megaflow on Wednesday 9th September 11:10
I seem to remember reading a run of at least 20 mins above 2500rpm is the correct procedure to aid cleaning, a thrash around town etc may just add more soot to the equation.
I know its probably snake oil but twice a year before a decent run i put a tin of dpf clean in a full tank of super duper diesel.
I know its probably snake oil but twice a year before a decent run i put a tin of dpf clean in a full tank of super duper diesel.
Be careful about expecting a warranty to cover DPF issues, it is a part that has a service life.
The only thing I have personally seen to clean DPFs properly is that Terraclean thing Ed China has his mug on. A couple of our customers have used it instead of spending large sums on a new DPF and it has worked.
The other thing to be wary of is that if you aren't near the replacing time for the DPF then you may have an underlying issue causing the engine to produce excess soot and the symptom is that the DPF starts getting clogged up irrespective of driving habits.
The only thing I have personally seen to clean DPFs properly is that Terraclean thing Ed China has his mug on. A couple of our customers have used it instead of spending large sums on a new DPF and it has worked.
The other thing to be wary of is that if you aren't near the replacing time for the DPF then you may have an underlying issue causing the engine to produce excess soot and the symptom is that the DPF starts getting clogged up irrespective of driving habits.
I doubt warranty will cover dpf blockage, only maybe if the detection system is failed, so a dpf pressure sensor for instance. Driving methods or use affect the dpf. A company called Protec also make a couple of cleaners, Forte possibly too, CRD is one of the cleaners that helps disperse water in the fuel, and DPF superclean is a dpf cleaning additive, but preventative really. It may help to add it, but the best thing is to drive the car around thirty miles normally, then from low speed in 2nd or third, use repeated full throttle, full rpm scale applications 10-12 times when the dpf is restricted, in order to generate extreme heat in order to assist a forced regeneration. It's a crude way of doing it but often required. The dealer will do it, and charge you for it, but may not do it as thoroughly, but may have a facility to set the car in a forced regen mode, probably just overfuelling during the run.
A problem you may have as mileage increases on these cars, is if the dpf is blocked due to one reason or another, that the car tends to add fuel during its own regeneration process, and if continually unsuccessful, the wasted fuel can contaminate the engine oil. Some cars show a high oil level, and it can be spotted if you're good at checking it, others that tend to use a litre over 2.5k which is fairly common, may appear to be using less and the symptom can go unnoticed as the reduced appearance of consumption can be due to the addition of fuel.
This can also have the appearance over time of looking like an oil leak at the intercooler, due to the reduced consistency of the oil naturally entering it, a leak at the pipes can be a clue to remove and clean it, at the same time changing the oil.
I would always renew the engine oil and filter if a dpf issue is suspected, BEFORE any attempt is made to regenerate the dpf. Just to protect the engine in case. I also would be inclined to check and drain the intercooler or intake tract of anything collected, as it can over time form a significant amount in owners cars that don't tent to exploit the full rpm scale, and when suddenly done to try this method of regeneration, it can be drawn into the intake and cause the engine to run away with itself, off throttle, causing damage beyond imagination.
Just my2p, essentially, check the dealer policy on charges relating to dpf issues before signing a jobcard, where you may be charged.
A problem you may have as mileage increases on these cars, is if the dpf is blocked due to one reason or another, that the car tends to add fuel during its own regeneration process, and if continually unsuccessful, the wasted fuel can contaminate the engine oil. Some cars show a high oil level, and it can be spotted if you're good at checking it, others that tend to use a litre over 2.5k which is fairly common, may appear to be using less and the symptom can go unnoticed as the reduced appearance of consumption can be due to the addition of fuel.
This can also have the appearance over time of looking like an oil leak at the intercooler, due to the reduced consistency of the oil naturally entering it, a leak at the pipes can be a clue to remove and clean it, at the same time changing the oil.
I would always renew the engine oil and filter if a dpf issue is suspected, BEFORE any attempt is made to regenerate the dpf. Just to protect the engine in case. I also would be inclined to check and drain the intercooler or intake tract of anything collected, as it can over time form a significant amount in owners cars that don't tent to exploit the full rpm scale, and when suddenly done to try this method of regeneration, it can be drawn into the intake and cause the engine to run away with itself, off throttle, causing damage beyond imagination.
Just my2p, essentially, check the dealer policy on charges relating to dpf issues before signing a jobcard, where you may be charged.
Megaflow said:
Aftermarket cleaners are snake oil.
Think about it, you are going to put ~0.5l of additive into a whole lot more fuel, pressurise it to 2000bar, inject it into a cylinder and compress it to the point where it burns.
How does such a small quantity of Eolys fluid in a PSA vehicle work then. 1l last about 80,000 miles Think about it, you are going to put ~0.5l of additive into a whole lot more fuel, pressurise it to 2000bar, inject it into a cylinder and compress it to the point where it burns.
Edited by Megaflow on Wednesday 9th September 11:10
Matt Seabrook said:
Megaflow said:
Aftermarket cleaners are snake oil.
Think about it, you are going to put ~0.5l of additive into a whole lot more fuel, pressurise it to 2000bar, inject it into a cylinder and compress it to the point where it burns.
How does such a small quantity of Eolys fluid in a PSA vehicle work then. 1l last about 80,000 miles Think about it, you are going to put ~0.5l of additive into a whole lot more fuel, pressurise it to 2000bar, inject it into a cylinder and compress it to the point where it burns.
Edited by Megaflow on Wednesday 9th September 11:10
http://www.citroenet.org.uk/miscellaneous/5th-stro...
So even the PSA system has nothing useful left after combustion.
Not all are snake oil. We use a Forte DPF cleaner in work and has saved more than one DPF. The Forte product works in the same way but is less concentrated and is deigned for a different purpose. So not all products are the same.
Some of the other information in this thread about changing oil is good advise. A lot of people assume all oil is the same and can use whatever they feel like but the correct oil is vital for the health of the DPF.
The PSA requires additive because of its location. The DPF isn't close coupled like most are it also has a cat before the DPF to help raise the temp in the DPF. To burn soot of with out additive requires about 600c so the PSA system would not get hot enough with the location of the DPF.
Some of the other information in this thread about changing oil is good advise. A lot of people assume all oil is the same and can use whatever they feel like but the correct oil is vital for the health of the DPF.
The PSA requires additive because of its location. The DPF isn't close coupled like most are it also has a cat before the DPF to help raise the temp in the DPF. To burn soot of with out additive requires about 600c so the PSA system would not get hot enough with the location of the DPF.
Edited by Matt Seabrook on Monday 21st September 20:53
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