10 year old D4D Yaris in limp mode(DPF?)

[Marcusthehat]

My first post on here, and concerning the daughter's car.

About 10 years old and the 1.4 diesel, with about 170,000 miles on, with very few short cold journies.

Anyway a couple of months ago she booked it in to the local Toyota dealer( due to a serious Stormont run MOT backlog over here she could not get an MOT booked and wanted a bona-fide franschised dealership mechanical clean bill of health in case of any issues with the Polis or insurance) for essentially  a $200.00 oil change. .  .  .

and only a couple of days later a warning light came on, unfortunately she then  took it to her excellent local mechanic that usually does all her work, who diagnosed a blocked DPF and after checking the dipstick, drained about 1 litre of overfilled oil from the sump, and after some driving it appeared to clear itself.

(Not that the dealership would have admitted anything anyway!)

So guessing the dealer will try a forced Regen, and if that does not work,  most likely a new DPF?

I suppose my question is how long should a DPF last, and how much should a new one from Toyota be?

Or is she better to stick with the Indy mechanic she knows and trusts?

Cheers,

Marcus

 

[Max_Headroom]

Google DPF cleaning there are lots of places doing it.

[Derek.w]

I try cat cleaner and give it a good run on a motorway or just drop a gear cat need tobe up to tempriture to regen but after its tried a specific number of times its set up a engine code thats needs to be removed with a code reader or disconnect the Battery can work providing the fault has cleared.

You may have a sensor that not working because its blocked with soot.

[Marcusthehat]

An update, of sorts, the car threw the same code, again, and the sump was overfull, again, so it seems that(& guessing the same as the diesel Mazdas of the same sorta vintage) the DPF fault is dumping unburned diesel into the sump, anyway the daughter was referred by her mechanic to a very Toyota knowledgable bloke who was ahead of her at every turn as she explained the symptoms, and he knew the underlying causes, having dealt with other similar age diesel Yaris's  with the exact same fault.

BUT

This bloke says there was a "service bullitin"(I think it was called?) issued by Toyota, to address this known issue, and since our daughter is the registered owner from new, surely she should have been contacted by Toyota about this needed work(and her address has not changed either btw), or it should have been done when the car was in with Toyota for a service and MOT checkover recently, where she was given a clean bill of health.

Thoughts please?

Marcus

P.S.

Apparently a new DPF is £1,000.00, plus fitting et. al.

She has near a years MOT still to run  .  .  . so perhaps "deleting" the DPF may well be an option or interim solution?

[Max_Headroom]

Many places offer a DPF cleaning service it may be worth searching your area. 

[Marcusthehat]

29 minutes ago, Max_Headroom said:

Many places offer a DPF cleaning service it may be worth searching your area. 

Max, thank you, I had seen that and passed this info on, however it was the service bullitin "non disclosure" aspect I was querying, plus anyway if the excess/unburned diesel is the underlying problem, that is only a very short-term temporary solution, yes?

And this "guru" comes highly recommended by a local long established and trustworthy bloke, and he would therefore be well au-fait with these work-arounds.

Thank you, 

Marcus

[Gerg]

1 hour ago, Marcusthehat said:

plus anyway if the excess/unburned diesel is the underlying problem

The way I understood this, the unburned diesel in the sump (in this and the Mazda) is a symptom not the cause.  The car monitors the DPF by using an electronic pressure sensor tee'd in before the DPF, and another one after it. 

If/when the pressure drop across the sensors is too great (i.e. the DPF is judged to be filling up with soot beyond a pre-determined trigger point), then the engine ECU (over) injects diesel fuel, timed to pass through the engine onto the DPF, this to heat the DPF and accelerate the burning of the accumulated soot into ash (which has a much, much reduced volume compared to the soot it comes from) - an active 'regen'. The ash is not designed to escape the DPF, it is trapped in the filter.

If the engine ECU 'sees' the regen as having failed because the pressure drop across the sensors is still too great after it has finished, then it will keep attempting regens - it's the only means it has to try to clean the DPF.

With regen after regen taking place, some of the diesel meant for the DPF gets past the rings and into the sump, which is what you are seeing when the dipstick level rises. 

(Some other engine parameters get changed during a regen to help get the engine extra hot, but I don't think they affect your situation.)

I have no knowledge of what's in the bulletin (perhaps @Devon Aygo , who works at a Toyota dealer (but not Toyota!) might find this thread as I've tagged him in, and kindly elaborate on what it is for).

I am happy for someone who knows better to correct me on the above, of course - my descriptions are simply what I've picked up from reading odds and sods.

[Marcusthehat]

Ah Ha! 

Thank you for that explanation Gerg.

Much appreciated.

[Gerg]

You are welcome.

On some other makes of cars, but I've not read about this with Toyotas, the pressure sensors, or their fairly narrow attachment pipes, can fill with sooty crud, or in the sensor's case, fail completely.  In that situation, the ECU is 'wrong-footed' and will repeatedly try to perform regens when they are not needed.

Also, and I'm not quite sure about this one, the engine ECU may adjust the EGR system during a regen (it would make sense), so as to help the exhaust to get really hot.  If your EGR system was not working 100%, again through crud build-up, then the regen might not be able perform properly.  I have a vague idea someone on this forum experienced this problem.

Sadly, at 170,000 miles, I can understand that Toyota's designers might have determined that the DPF being full of ash was a reasonable lifespan for it, and that as a 'filter', it is a service item of sorts. Although the thought of such an expensive service item is more than a bit sick-making!

Whilst looking just now for a picture of an 'overshoot filter', which is used in the DPF construction, I've just stumbled upon this, which goes into some more detail:-

https://en.wikipedia.org/wiki/Diesel_particulate_filter

And this following article is good, especially the first picture, which de-mystifies what is going on in the filter structure:-

https://www.ctscorp.com/products/sensors-2/rf-dpf-sensor/diesel-particulate-filter-dpf-knowledge-base/basics-dpf-operation/

I'd like to think that the filter can be cleaned out, but have no personal experience (and my 2009 diesel VAG car had no DPF when new!). 

[flash22]

I would do a leak down test on the main 4 injectors, check the differential lines are clear, and see what the differential sensor is reading

Is it a Mk2 or Mk3 yaris ?

 

TSB's are not the same as Recalls

some light reading - related tsb numbers at the bottom of the page

https://toyota-club.net/files/faq/21-07-20_faq_nd-engine_en.htm

[Marcusthehat]

It was the then "new model" bought about 2011 from recall.

Guessing that makes it a Mk3?