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Hi all,
Just putting this out there for others to maybe try out and comment on what they observe.
Having owned and maintained a number of two stroke bikes over the years I wondered if de-cokeing a two stroke exhaust and burning the DPF were similar in that once the carbon is lit up it would completely burn away if fed a steady stream of hot oxygen.
A several times now I've brought the engine up to a very fast idle (1200-1500rpm) just as the regen is finishing up (say DPF load at 10%) and held it there.
What I see is the first two exhaust gas sensor temps drop off (as expected) once the ECU completes it regen cycle HOWEVER the third sensor continues to rise slightly, topping out at 650-700C. The first time I did this the third sensor stayed over 650C for between 5 and 10 minutes (didnt think to time it) even though sensor's 1 and 2 had both dropped well below 200C after only a few minutes.
Once the temperature reported by the third sensor started to drop it fell away quite rapidly. During my test the DPF % dropped to 2% at about midway through and stayed there apart from the occasional -2% readings.
Subjectively the car felt a lot more responsive after this however it coincided with a sheduled service - so it could just be the turbo loving the fresh oil which is totally a thing.
Subsequent repeats of this "proceedure" with other automatic regens and 1 manual regen behaved the same however the time it took for sensor three to start to cool down wasn't neary as long (sub 5 minutes) as the first one
Sooo I'm thinking :-
1. Once the carbon in the DPF is well alight the it can be forced to burn itself out completely by holding high revs with no load (good volume of hot, relatively oxygen rich exhaust gas)
2. Once the last of the carbon is burnt away the DPF core temperature drops rapidly (this fits my memory of de-cokeing two stroke exhausts with a blow torch and a hair dryer)
3. This possibly burns the DPF much cleaner than most automated regens except for the ones we fluke under ideal driving conditions (I've seen it get down to 4% once or twice on the road and 6% reasonably frequently) .
4. This MAY improve DPF performance & lifespan ??? At worst its probably a benign, yet fascinating, waste of my time. :-). Lord knows we 2.8 owners are fascinated with our DPF's
Anyway would be interested in others thoughts and experiences if you've got nothing better to do :-)
cheers
-Rod
PS: I've had the dreaded white smoke a couple of times and had the dealer regen performed "successfully" once. To the best of my knowledge the last ECU upgrade was in 2017. And my MY2016 is just north of 50,000km,
Just putting this out there for others to maybe try out and comment on what they observe.
Having owned and maintained a number of two stroke bikes over the years I wondered if de-cokeing a two stroke exhaust and burning the DPF were similar in that once the carbon is lit up it would completely burn away if fed a steady stream of hot oxygen.
A several times now I've brought the engine up to a very fast idle (1200-1500rpm) just as the regen is finishing up (say DPF load at 10%) and held it there.
What I see is the first two exhaust gas sensor temps drop off (as expected) once the ECU completes it regen cycle HOWEVER the third sensor continues to rise slightly, topping out at 650-700C. The first time I did this the third sensor stayed over 650C for between 5 and 10 minutes (didnt think to time it) even though sensor's 1 and 2 had both dropped well below 200C after only a few minutes.
Once the temperature reported by the third sensor started to drop it fell away quite rapidly. During my test the DPF % dropped to 2% at about midway through and stayed there apart from the occasional -2% readings.
Subjectively the car felt a lot more responsive after this however it coincided with a sheduled service - so it could just be the turbo loving the fresh oil which is totally a thing.
Subsequent repeats of this "proceedure" with other automatic regens and 1 manual regen behaved the same however the time it took for sensor three to start to cool down wasn't neary as long (sub 5 minutes) as the first one
Sooo I'm thinking :-
1. Once the carbon in the DPF is well alight the it can be forced to burn itself out completely by holding high revs with no load (good volume of hot, relatively oxygen rich exhaust gas)
2. Once the last of the carbon is burnt away the DPF core temperature drops rapidly (this fits my memory of de-cokeing two stroke exhausts with a blow torch and a hair dryer)
3. This possibly burns the DPF much cleaner than most automated regens except for the ones we fluke under ideal driving conditions (I've seen it get down to 4% once or twice on the road and 6% reasonably frequently) .
4. This MAY improve DPF performance & lifespan ??? At worst its probably a benign, yet fascinating, waste of my time. :-). Lord knows we 2.8 owners are fascinated with our DPF's
Anyway would be interested in others thoughts and experiences if you've got nothing better to do :-)
cheers
-Rod
PS: I've had the dreaded white smoke a couple of times and had the dealer regen performed "successfully" once. To the best of my knowledge the last ECU upgrade was in 2017. And my MY2016 is just north of 50,000km,
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