Diesel F150 Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
19 Posts
Discussion Starter #1
Has anybody seen the DPF filter seem to loose density (time from empty to full) change?

After a fresh regen the truck used to go from 0 to 100% full in a somewhat linear fashion.
It now has 5000km and after a full regen it will start at either 5 or 10% full and jump to 50% or so in short period of time (<50km) and continue to 100%.

Re generations are becoming more frequent.

Has anybody else seen this?
 

·
Super Moderator
Joined
·
779 Posts
Yes I noticed that. It would clean itself on the way to work down to zero and by the time I drove 10 miles on the freeway home it was back to 40-50%. I can only assume it was from the type of driving I do. Idling and lots of stop and go.
 

·
Premium Member
Joined
·
309 Posts
Mine is doing some odd things. Two weeks ago I was at 100% and I was heading out down the interstate 44 miles. Great, clean it out down to zero!

It only made it to 10% then went to 15%. By the time I returned home it was up to 55%. 90 miles round trip with about 6 or so city. Now, the outside temp was near 100 F so maybe that had something to do with it. I ran about 74 mph but with heavy traffic it was on cruise control less than half the time.
 

·
Registered
Joined
·
107 Posts
Yes if I am driving in the city, it climbs from 0 to 70 pretty fast, then seems to slow down from there, I did 40 miles once with it showing 95%... I think it's just something in the calibration, as it uses pressure differentials to determine when it's full, and only really has distinct calibration points at 0% and 100%, so anything in between the computer is just guessing.
 

·
Registered
Joined
·
37 Posts
The %Full on the IPC definitely doesn't tell the whole story. There are at least three other calculations of soot loading in the computer. The closed loop calculation uses actual sensor input (pressures), to infer the soot loading. The open loop calculation uses engine operating data to calculate a theoretical soot amount. This calculation has a minimum accumulation rate so it will go up whether you are making soot or not. I've observed that the IPC displayed amount generally follows the open loop calculation once it's above 50%. My closed loop calculation has been around 25% full when the open loop (and IPC) number reach 100%. You can safely go well above 100% full on the IPC if you know the closed loop % loading and monitor your exhaust pressures.
 

Attachments

·
Administrator
Joined
·
481 Posts
Having watched dozens of Active Regens live via FORScan iPhone app, I am convinced that the accuracy of the DPF Full % below 40% is a bit murky, i.e. I have seen the dashboard display continue down to 0% while the DPF_REGEN_PCT% on FORScan stop anywhere between 25% and 40%, so the computer must use some other variables as input for the calculations below 40% Full. @CYODESL also indicated his DPF_REGEN_PCT% stopped around 48% in this post: https://www.dieself150forum.com/forum/20862-post101.html

I think this also explains the variability between 0% and 10%, so I have stopped worrying about always getting down to 0% after an Active Regen, as I think they don't have an accurate way to really measure below 40% Full.

I also see the FORScan-enabled dashboard display jump up to 40-50% after driving for a single day after an Active Regen down to 0% the day before. Perhaps this low-end variability is one of the reasons Ford decided to bury DPF Full % from the owner/end user to avoid having to answers questions on why it doesn't go to 0% or why it jumps to 50% Full in a day or two...
 

·
Premium Member
Joined
·
309 Posts
Interesting! I just assumed the dash data was absolute. That info makes it easier to just relax and let the systems do their thing. I would prefer the dpf just be gone. Someday...
 

·
Registered
Joined
·
68 Posts
mine is doing the same exact thing, I did an OCR last evening.. took about 20m and went to 0% loaded.

today i drove maybe 10 miles and its back to 40%.. this thread gives me some confidence it is behaving as it should.

that said.. i dont really like subjecting my engine to the heat i saw generated yesterday during the OCR. it was my first one and it made me feel uncomfortable to say the least. I am again considering a delete.
 

·
Super Moderator
Joined
·
779 Posts
mine is doing the same exact thing, I did an OCR last evening.. took about 20m and went to 0% loaded.

today i drove maybe 10 miles and its back to 40%.. this thread gives me some confidence it is behaving as it should.

that said.. i dont really like subjecting my engine to the heat i saw generated yesterday during the OCR. it was my first one and it made me feel uncomfortable to say the least. I am again considering a delete.
Its ok for them to heat up as every diesel on the road since 07 does it, but yes a delete is a smart idea. Will keep it happy for years to come.
 
  • Like
Reactions: Jgleadle
1 - 9 of 9 Posts
Top