DPF - Change based on interval or if problems?

Xcellor

Looks like my 520D will show that DPF change is required (since its between 125k miles-150). It's around 2000 euro for this to be done.

I've no symptoms or anything to say something is wrong with it and it's driven proper distances every day bar weekend.

Seems crazy money to spend. Is this the type of thing to fix if broken or symptomatic?

Toyotafanboi

I'd leave it in place once it's not giving trouble. You virtually never see a DPF needing replacement once the car is driven as intended, even on mega high mileage stuff.

You are able to check it's soot and ash content through the OBD system, that'll give you an idea of where it's at in its lifespan if you are worried.

bazz26

Only replace it when it starts getting problematic.

Xcellor

Toyotafanboi wrote: »

I'd leave it in place once it's not giving trouble. You virtually never see a DPF needing replacement once the car is driven as intended, even on mega high mileage stuff.

You are able to check it's soot and ash content through the OBD system, that'll give you an idea of where it's at in its lifespan if you are worried.

I have access to ISTA+ which is the BMW diagnosis tool used in garages and its showing a warning but appears more down to mileage than anything. This also ties in with BMWservice.ie which is now showing it as an option when I put in my reg I can think of so many other things I'd spend 2000 euro on...

I have the option using the tool of just clearing the warning and marking it as "replaced" which will effectively stop any warning being thrown for another 100,000 miles or so.

If I'm driving decent miles with engine reaching proper operating temperature should I just continue "as is" . I see products like

https://www.micksgarage.com/d/engine-oils-and-lubricants/products/2099844/jlm-diesel-particulate-filter-dpf-cleaner-375ml

Waste of money?

Cerco

Does the diagnostic software allow you to force a regen?
I remember much discussion around dpf and if I recall one recommendation from one of the BMW forums was to do a good uninterrupted run on a motorway at a constant speed around 100Km/hr. should cause it to regenerate. Check through the fora for more info.

Some interesting info here on Bmw dpf:

https://5series.net/forums/diy-do-yourself-14/diy-maintenance-dpf-94725/

Xcellor

Cerco wrote: »

Does the diagnostic software allow you to force a regen?
I remember much discussion around dpf and if I recall one recommendation from one of the BMW forums was to do a good uninterrupted run on a motorway at a constant speed around 100Km/hr. should cause it to regenerate. Check through the fora for more info.

Some interesting info here on Bmw dpf:

https://5series.net/forums/diy-do-yourself-14/diy-maintenance-dpf-94725/

It probably does. It's very comprehensive tool. The other day I nearly pooed myself when it decided based on action to turn off the car and "reboot" it to complete. Thankfully car turned itself back on and everything reported fine afterwards ...

I have no reason to believe my style of driving wouldn't clear the DPF out. I drive to work early morning and although not motor ways most of the time I'm 100 kph.

I'll "replace" the DPF from the point of view of the software and then next time I bring it into BMW I'd assume the car will sync with computer and since the warning has been cleared will update their computers so it isn't recommended again. They have no idea whether I've replaced DPF through an independent..

Toyotafanboi

Honestly I think that's a bad idea. I'd just leave everything as is.

The DPF as far as you know is working fine, just leave it be.

If you go telling the car that the DPF is replaced it'll be expecting a totally different set of measures values to what is actually in existence in the DPF and you'll unfold a world of heartache for nothing.

cruizer101

Xcellor wrote: »

If I'm driving decent miles with engine reaching proper operating temperature should I just continue "as is" . I see products like

https://www.micksgarage.com/d/engine-oils-and-lubricants/products/2099844/jlm-diesel-particulate-filter-dpf-cleaner-375ml

Waste of money?

I often think a lot of these fuel additives are snake oil, and this one may well also be, but there is some science behind it.
I've a diesel myself and am a probably a bit borderline on the ideal driving conditions for dpf, so had done some research before.

The cerium they talk about is a catalyst which does reduce the temperature at which soot particles will burn off (so in theory will burn off during slower shorter journeys than usual), but I couldn't really find further details on the real life effectiveness of these additives.

Xcellor

Toyotafanboi wrote: »

Honestly I think that's a bad idea. I'd just leave everything as is.

The DPF as far as you know is working fine, just leave it be.

If you go telling the car that the DPF is replaced it'll be expecting a totally different set of measures values to what is actually in existence in the DPF and you'll unfold a world of heartache for nothing.

Good point. Will leave as is but if I start getting a warning popping up that it needs to be changed I'll look further into it...

mgbgt1978

A forced Regen is not going to make any difference. The Car is doing constant Regens anyway at a preset Soot Level (or mileage level if it's mainly M/way use). This soot is burnt off during the Regen and a certain amount of Ash is then produced.
The only figure that matters is the Ash Level, and what BMW consider to be the amount of Ash that constitutes a 'Full' DPF.
The BMW mileage DPF replacement Indicator is meaningless, as it cannot reference the Ash Level.
Does your software show the Ash level in the DPF, and is it well below BMW's 'DPF replace' limit ?

Xcellor

mgbgt1978 wrote: »

A forced Regen is not going to make any difference. The Car is doing constant Regens anyway at a preset Soot Level (or mileage level if it's mainly M/way use). This soot is burnt off during the Regen and a certain amount of Ash is then produced.
The only figure that matters is the Ash Level, and what BMW consider to be the amount of Ash that constitutes a 'Full' DPF.
The BMW mileage DPF replacement Indicator is meaningless, as it cannot reference the Ash Level.
Does your software show the Ash level in the DPF, and is it well below BMW's 'DPF replace' limit ?

I only looked briefly at the warning as my main concern was fixing a faulty O2 sensor. But how would it possibly know ash level ? Assuming a properly ran dpf with little fuel contamination ash should be negligible?

_Kaiser_

I am having ongoing recurring DPF issues at this stage where the car (3L TDI A6) gets a bit smokey and has gone into limp mode once or twice. So far a 40km run in 4th gear at motorway speeds has sorted it, but it is clogged I'm told.

This is despite daily motorway runs of about an hour each way. I think it's down to the bigger engine as it means it barely tips 2k RPM at 120-ish? Otherwise it makes no sense to me!

Toyotafanboi

The DPF is designed according to the application though and most diesels are around 2k rpm at motorway speeds.

If it's blocked, it's either at the end of its useful life which is unlikely or there is a fault causing it to block.

_Kaiser_

Toyotafanboi wrote: »

The DPF is designed according to the application though and most diesels are around 2k rpm at motorway speeds.

If it's blocked, it's either at the end of its useful life which is unlikely or there is a fault causing it to block.

It's possible it's just end of life I suppose... 9 year old car with over 380k km on it.

mgbgt1978

Try asking on the DIY section if anybody near you has vagcom (or even a cheap ELM and the Vag DPF app..... full version). Either will tell you the ash level in your DPF . Not sure what the 'full' amount is in your car but a quick Google should get you the figure.

NomadicGray

Id wait and see if theres problems but keep a close eye on your oil levels, any rise could be an indication