X5 35d "de-particle" process

[Diesel Guy]

The regen process is different for each OEM. The addition of raw diesel fuel to the exhaust stream will chemically increase the temperature of the particulate filter, and chemically remove the carbon trapped on the DPF. This process does not remove ash. Ash is a component of lubricating oil, that gets past the piston rings, and since an ash molecule is larger than carbon, it remains in the DPF until mechanically removed. This is why it is important to only use a low ash oil that is recommend by the manufcturer.

Here's a link to the Cummins site with a video that shows what's going on during an active regen event...similar to what BMW does, but not 100% the same....

The DEF fluid is only associated with NOx reduction, and takes place in a separate catalyst, after the DPF. A tailpipe sensor manages the injection of DEF to control NOx

[deutsch100]

WOW, great and super informative responses!! Thank you so much. Yes, the smell is "sweet" as some described, but not a yummy sweet! It's like sweet burning cardboard!

[Diesel Guy]

The link...

Cummins Every Time - On-Highway - 2010 On-Highway - Cummins Aftertreatment System

[Aidan]

For anybody that is equipped with a DPF, should take their car out on the motorway and give it a good spiritual drive occasionally. DPFs become problematic with town and city driving.

[GoVols!]

Ive never noticed any smell in mine, but if you pay attention on a highway trip the process is very noticable on the instant MPG guage. Cruising at 70, the mpg's will all of a sudden drop from ~30 to 23-24 for 15-20 miles.

[motordavid]

Don't own a diesel, have never owned a diesel, may never own a diesel...
but there sure are some quality info posts in this Thread, imo.
What a Board!
BR, mD

[SkipSauls]

Is there any sort of indicator that it is happening? Like others, mine seems to prefer to wait until I'm pulling into the garage to departicalize/regenerate/whatever. I'd like for it to display something in the iDrive or idiot lights saying it was happening, or preferably, was about to happen. I'd gladly drive around the block a couple of times to allow others to experience the "sweet smell" rather than stinking up my garage!

[GoVols!]

Originally Posted by SkipSauls

Is there any sort of indicator that it is happening? Like others, mine seems to prefer to wait until I'm pulling into the garage to departicalize/regenerate/whatever. I'd like for it to display something in the iDrive or idiot lights saying it was happening, or preferably, was about to happen. I'd gladly drive around the block a couple of times to allow others to experience the "sweet smell" rather than stinking up my garage!

Watch your mpg's on the instant guage. When the process occurs it kills the mileage.