Dpf cleaning or buying

[Avocet]

The Eloys bottle is tucked well up, next to the diesel tank - it has to be dropped down to refill. Expect to use around 3 litres or so.
The confusing thing is, just like the Adblue systems, the car won't start if the tank is dry! It's therefore vital for the sensor to work.
I guess you have been lucky there!
John

I think they'll start if the run out of Eolys. They just soot-up the DPF. They won't start without AdBlue, because that's a legal requirement.

 

[Avocet]

I read dpf filters have average life of 100,000 miles and if faulty or poorly maintained much shorter.

No, they're supposed to last the life of the car. I've certainly seen 250,000 mile cars on their original DPFs.

 

[trevorbayliss]

Ok, so no sensor. Thats fine and I will remember in 70k miles to top it up again. Hope to still have it as its in good condition.

Having the dpf cleaned out when the liquid it topped up this week.

 

[Avocet]

I know mine is a different engine - Toyota - and possibly a different system but, if the OP's system operates in a similar fashion to mine, what you've posted would be incorrect.


Toyota main dealer told me themselves their dpf cleaning cycle ONLY kicks in if:

- the sensor says you're doing >40 mph, AND
- the sensor says you're doing >3000rpm.

Driving to the Moon and back, at 70 mph and in 6th gear, even if done weekly, WILL clog the dpf, as the cleaning cycle will never be triggered.

My frugal motorway driving was - according to Toyota - what had caused the blockage warning light in the first place.

As has been said, I think the dealer was talking cobblers. DPFs regenerate in one of two ways:

"Passive regeneration". They just do this when you're driving normally and they're hot enough. If you have an open fire, you might notice the back of the hearth is all sooty, but there's a clean bit of brick, right behind where the fire is hottest? That's because the carbon particles are actually burned to CO2. The DPF does the same job, so when you're driving at more than about 40 or 50, continuously for more than 20 minutes or so, the DPF is usually hot enough to do what the open fire does, and burn the soot out. As soon as you lift off the throttle or come to a stop, it starts cooling down, and then that can't happen.

"Active regeneration". They only do this when they haven't got hot enough for a passive regeneration for a while, and they're starting to fill with soot. Different manufacturers have different strategies, but they all try to do the same thing - get the DPF hot enough to burn off the soot. The handbook usually gives advice on how best to look after the DPF, and I would trust it over a dealer any day. Lots of people say you have to drive them flat-out, but that can be counter-productive. Those of us who can remember old diesels, will have seen that when you boot them, they usually chuck out a bit of black smoke. Diesels make maximum power when there's a bit more fuel than there is oxygen available to burn it completely. So working them hard, is exactly the situation when they are producing the most soot! Far better, to just put a "medium" load on them for 20 minutes or so, constantly. Just to make sure the exhaust temperature doesn't drop.

 

[Avocet]

Ok, so no sensor. Thats fine and I will remember in 70k miles to top it up again. Hope to still have it as its in good condition.

Having the dpf cleaned out when the liquid it topped up this week.

They definitely DO have a sensor, it just doesn't put a light on. If it were my car, I'd try just topping up the Eolys (it is eyewateringly expensive, I'm afraid) and see how I got on. Depending on how it's driven the DPF might actively regenerate between 500 and 1000 miles, so if the dosing system isn't working, your DPF will just block up again.

 

[Brigadier]

Far better, to just put a "medium" load on them for 20 minutes or so, constantly.

Which is c. 3000 rpm, rather than c. 1500 when doing 70 in. 6th, isn't it?

Oh, and the handbook in mine is feggin' useless on many things, and utterly devoid of dpf care advice.

 

[Avocet]

Which is c. 3000 rpm, rather than c. 1500 when doing 70 in. 6th, isn't it?

Oh, and the handbook in mine is feggin' useless on many things, and utterly devoid of dpf care advice.

3k is quite a lot for a diesel. here's what my last Peugeot 5008 handbook said:

And here's what Mrs. Avocet's current Skoda handbook says:

You really don't need to thrash them!

 

[Brigadier]

3k is quite a lot for a diesel. here's what my last Peugeot 5008 handbook said:

View attachment 331439


And here's what Mrs. Avocet's current Skoda handbook says:


View attachment 331440


You really don't need to thrash them!

I hear what you're saying, but we're not far apart in what we're saying.

- above a certain speed
- at elevated revs
- for an extended run

What's 500rpm anyway, between friends?

 

[Avocet]

I hear what you're saying, but we're not far apart in what we're saying.

- above a certain speed
- at elevated revs
- for an extended run

What's 500rpm anyway, between friends?

Yes, I think the only different thing, is the load under which the engine is. I'm advocating very light load, so that it runs quite weak and the soot loading into the DPF isn't that great. I wonder if mechanics sometimes specify high RPM because it then forces people to use the lower gears? 3000 revs in top gear on most diesels new enough to have a DPF, will be licence-losing territory, so if that forces the to drop down a gear or two, it will mean lighter load and a weaker mixture?

 

[Brigadier]

is the load under which the engine is.

If it is anything like pedalling a bike, high rpm (which is equivalent to high cadence) places less load on the engine / cyclist, than lower rpm (lower cadence) does.

That's why "recovery" rides are often referred to as "spinning".

 

[Avocet]

If it is anything like pedalling a bike, high rpm (which is equivalent to high cadence) places less load on the engine / cyclist, than lower rpm (lower cadence) does.

That's why "recovery" rides are often referred to as "spinning".

Yes, that's what I mean. You can't exert as much torque at high RPM.