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Toyota Corolla and Verso - How to care for a DPF? - Herr Sandwichmann

My car has a DPF, and in light of the many stories of problems with these filters, I wonder if other forum members have any advice or tips. Most mileage on my car is done on motorways in rush hour traffic, at 60-75 mph indicated, which relates to about 1750-2300rpm in top gear. Some short urban journeys too, though I try to avoid these for several reasons. I tend to boot it on the m-way by sticking in 4th when I join and running the engine up to about 3500rpm for a short while, maybe a couple of minutes. When I do this a cloud of black smoke comes out of the exhaust, as if the car's clearing its throat. Is it the build-up of this sort of soot which does for filters in the end?

Toyota Corolla and Verso - How to care for a DPF? - oilrag

Yes, it`s soot particles building up in the DPF and not getting burnt off by a regeneration. If it were mine, I would be doing exactly what you are doing currently. in particular running it in 4th at higher revs for a period.

Mine, doesn`t have a DPF but whenever I get the chance on a long Motorway hill, I drop it into 4th at around 60mph, then boot it up to 4,000 revs, before changing into into 5th at the top.

Toyota Corolla and Verso - How to care for a DPF? - Herr Sandwichmann
Many thanks.
Toyota Corolla and Verso - How to care for a DPF? - craig-pd130

The latest-generation DPFs tend to be a catalyst-coated matrix, these don't use a fuel additive to help the regeneration but instead rely on the catalyst coating in the DPF to lower the required reaction temperature.

When you're driving with engine fully warmed up (i.e. has been running for over 10-15 minutes) and with engine rpm above 2000 and usually above about 40mph, the exhaust gases will heat the DPF enough for regeneration to occur "passively". That is, the DPF is hot enough to start coking the soot to ash.

I've seen data logs from a Skoda Superb that shows under these conditions, the DPF will go from a 50% soot-loading to under 5% (i.e. a complete regeneration) within 6 to 7 minutes.

So if you're cruising at above 2000rpm on a motorway it will regenerate quite quickly. High loading and rpm will get the temperatures up quickly, but once the burn starts it will continue, you don't need to keep thrashing it.

You get 'active' regeneration when the soot loading in the DPF is high (over 50%) and the car isn't being driven in conditions that would allow a passive regeneration. Active regens use extra fuelling (so some unburnt fuel gets into the DPF and ignites). It is these active regen cycles that can get interrupted by switching-off the engine mid-regen, etc.

My own Mondeo 2.0 TDCi with DPF is used for mostly short trips (under 5 miles) with occasional longer blasts, and is fine. My tip is keep rpm above 2,000 on any open-road journey -- this is in the peak torque band so it's good for responsiveness and keeps the DPF clean.

Toyota Corolla and Verso - How to care for a DPF? - yokel38

Toyota's DPF is a self cleaning variety, and theoretically should last the life of the vehicle. I have never seen or for that matter, never even heard of a single issue on any Toyota with a DPF fitted.


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