Isuzu DPF yet again!

[Cowabunga]

2015 model

It is now nearing the end of 2020 and you cover well over 25,000 miles annually.

 

[Courier]

Could be why, Mrs N had until recently a VW Tiguan, because all it did was short journeys the warning light would keep coming on, it was then up to me to give it a good thrashing to make it regen.

But it is virtually impossible to thrash a car which does 73 mph on cruise control in 6th gear at well under 2000 rpm - I have had a VW engined vehicle running up the A1 for 20 minutes in 3rd gear approaching the red line (73 mph and check the fluid levels first ) with “regeneration fluid” in a near empty diesel tank which wouldn’t trigger a regen despite having had a previous Terraclean within 5 k miles and permanently connected OBD 11 Diagnostics to wipe fault codes on the move every 5 minutes it still wouldn’t set off the regen.

 

[Sharpy]

But it is virtually impossible to thrash a car which does 73 mph on cruise control in 6th gear at well under 2000 rpm - I have had a VW engined vehicle running up the A1 for 20 minutes in 3rd gear approaching the red line (73 mph) with “regeneration fluid” in a near empty diesel tank which wouldn’t trigger a regen despite having had a previous Terraclean within 5 k miles and a permanently connected OBD 11 to wipe fault codes on the move every 5 minutes it still wouldn’t set off the regen.

Overload it and drive up a very steep hill? Or a rolling road?

 

[Tomr10]

It’s all new diesels they need the miles know somebody with a merc that always has a engine light on as he just dose the do the miles it needs

 

[Courier]

It’s all new diesels they need the miles know somebody with a merc that always has a engine light on as he just dose the do the miles it needs

Not that simple with many which go into a pre-limp mode and some functions (eg. Cruise Control) stop working ....

 

[Cowabunga]

There seems to be a misapprehension by some that 'thrashing' is needed by normal engines in order to regenerate. That is not the case. What is needed is normal driving at 50 to 60mph or around 1800 to 2500 rpm under reasonable load. If however the DPF has failed to regen several times, as is the case often in poorly designed systems and engines run very lightly or on short trips where the engine does not run hot enough for long enough.
The fuel contamination in the sump is the result of design decisions taken where the DPF is both situated too far from the combustion chamber and fails to heat sufficiently to regen, combined with a cheap 'solution' of overfuelling during the exhaust stroke to try and increase the heat. This sprays fuel which flows down the cylinder walls and into the sump and therefore the oil. This issue is not unique to Isuzu and JLR have had big problems which they have only very recently sorted, by redesigning the cab bulkhead in order to allow space for the DPF to be located directly off the turbo. There is no cure for earlier transversely mounted Ingenium engine'd vehicles.
Other brands, like the Ford Ranger, use a fifth injector [of sorts] in the exhaust, situated near the DPF, that sprays diesel directly in to the exhaust just forward of the DPF, this avoiding lubricating oil contamination.

Once the DPF is blocked, it can be a heck of a job to get working properly again.

 

[cheggars]

There seems to be a misapprehension by some that 'thrashing' is needed by normal engines in order to regenerate. That is not the case. What is needed is normal driving at 50 to 60mph or around 1800 to 2500 rpm under reasonable load. If however the DPF has failed to regen several times, as is the case often in poorly designed systems and engines run very lightly or on short trips where the engine does not run hot enough for long enough.
The fuel contamination in the sump is the result of design decisions taken where the DPF is both situated too far from the combustion chamber and fails to heat sufficiently to regen, combined with a cheap 'solution' of overfuelling during the exhaust stroke to try and increase the heat. This sprays fuel which flows down the cylinder walls and into the sump and therefore the oil. This issue is not unique to Isuzu and JLR have had big problems which they have only very recently sorted, by redesigning the cab bulkhead in order to allow space for the DPF to be located directly off the turbo. There is no cure for earlier transversely mounted Ingenium engine'd vehicles.
Other brands, like the Ford Ranger, use a fifth injector [of sorts] in the exhaust, situated near the DPF, that sprays diesel directly in to the exhaust just forward of the DPF, this avoiding lubricating oil contamination.

Once the DPF is blocked, it can be a heck of a job to get working properly again.

What oil is in the sump makes a big diffrence to the isuzu. This one works a lot Better with morris oil HD9 in it for some reason. The other oil we've had in it was supposed to be the same spec, but it regens less often with the HD9 .

 

[Timbo]

But it is virtually impossible to thrash a car which does 73 mph on cruise control in 6th gear at well under 2000 rpm - I have had a VW engined vehicle running up the A1 for 20 minutes in 3rd gear approaching the red line (73 mph and check the fluid levels first ) with “regeneration fluid” in a near empty diesel tank which wouldn’t trigger a regen despite having had a previous Terraclean within 5 k miles and permanently connected OBD 11 Diagnostics to wipe fault codes on the move every 5 minutes it still wouldn’t set off the regen.

Conditions for regen to begin are not low load and high rpm - for vws its broadly 1600 to 3000rpm and 40% to 60% engine load, so your attempted regen driving would never work. It also will not actively regen if the soot load is over a certain figure.

 

[Courier]

Conditions for regen to begin are not low load and high rpm - for vws its broadly 1600 to 3000rpm and 40% to 60% engine load, so your attempted regen driving would never work. It also will not actively regen if the soot load is over a certain figure.

Basically it needed a replacement new DPF.

It’s sorted now ...

 

[Netherfield]

Never had a problem getting it to regen, it was just a waste of time and diesel having to get it warmed up to do it.

The car did have other issues, fill it with adblue, but sometimes it didn't register and would then give a countdown to when it would stop working, couldn't get it into a VW dealers because of lockdown, independants didn't have the software upgrade needed. I've got to thinking 'stuff diesel and have a petrol instead'.

 

[Timbo]

Never had a problem getting it to regen, it was just a waste of time and diesel having to get it warmed up to do it.

The car did have other issues, fill it with adblue, but sometimes it didn't register and would then give a countdown to when it would stop working, couldn't get it into a VW dealers because of lockdown, independants didn't have the software upgrade needed. I've got to thinking 'stuff diesel and have a petrol instead'.

Yours never managed to get blighted with VW's "fix software" did it ? That does cause unending woe.

 

[Netherfield]

Yours never managed to get blighted with VW's "fix software" did it ? That does cause unending woe.

No that was on the pre adblue engines.

 

[smallholder99]

what age diesel would you have to go back to avoid this electronics on the engine

 

[Cowabunga]

what age diesel would you have to go back to avoid this electronics on the engine

Probably around eight to ten years ago when soot filters DPF were made mandatory and probably twenty to avoid cats, and thirty to avoid EGR. Two years to avoid Adblue on many pickups. This being 2020 for future reference.

 

[Womblefarrier]

Tempted to have a go and take DPF off and and scrape it through, then chuck it into a hot bonfire till it’s red hot! But suppose that won’t work either

 

[Timbo]

Tempted to have a go and take DPF off and and scrape it through, then chuck it into a hot bonfire till it’s red hot! But suppose that won’t work either

Nope.

 

[Courier]

Tempted to have a go and take DPF off and and scrape it through, then chuck it into a hot bonfire till it’s red hot! But suppose that won’t work either[emoji38]

Will need a professional re-map ....

 

[shelly reynolds]

So do Adblue engines suffer all these problems,

 

[Timbo]

So do Adblue engines suffer all these problems,

More complicated with more sensors and more likely to play up

 

[Cowabunga]

So do Adblue engines suffer all these problems,

Not all engines suffer any problems although some engine models are more prone to certain issues than others. Adblue is yet another 'potential' series of failure points to add on top of any existing issues, should there be any.