Early on, it was only one side of the engine, all 4 cylinders. It may still be just one bank of cylinders.

The rumor, never verified, that the TSB for the EGT sensors, Ford change the strategy to all 8 cylinders. I have never seen any verification of this, so it may only be a rumor.

On the 2011, it is only the driver side bank of cylinders during the exhaust stroke (passenger supplies EGR). Ford does not dump raw fuel (external of the engine injectors) into the DOC/SCR/DPF hardware.

Good info here. And yes, I like to monitor all systems on the truck. I would hope to be aware of a issue before it becomes critical. That is why I asked in another thread if it was normal to go 1300 miles without a regen during towing. With the cost of fuel pumps, sensors, converters, and whole engines it would be foolish not to take a interest in how your truck is performing.

For a visual and if I remember correctly, the 32,511 sample was where I experimented with completing as many active regeneration's as possible for the duration of that oil change (truck was a daily driver). I learned it certainly makes a difference in fuel dilution but it is time consuming plus the cost of extra fuel and extra miles on the truck. With the current design, fuel dilution is going to happen and a majority of owners just drive and shut down.


https://cimg4.ibsrv.net/gimg/www.for...68a55c279f.png

First off, unless you have a tuner that have modified the regen distance, you never exceeded 500 miles since the completion of the last regen before another started. In 1300 miles, you had at least 2 active regens. You might not have seen the pop up indicating it was going to regen.

Second, if you have the Exhaust Filter screen activated, you would be able to see if you were approaching regen or maybe you were finishing up a regen.

The 6.7 uses variance in EGT sensors to calculate soot load in the DPF filter. It does not automatically trigger a regen at 500 miles but will when the temp drops enough degrees from the front of the filter to the end of the filter. Highway driving at constant speed will burn much of the soot out on its own. Shorter regen cycles are typically caused by stop and go driving where you accelerate pre-boost which creates black smoke then caught in your dpf

The DPF pressure sensor is involved as well.

Ford has the limit set to 500 miles for a regen to occur regardless of the DPF load. While towing my trailer, I have seen my truck regen many times with less than a 100%/Filter Full condition but 500 miles limit was reached.

Only temps above 725-750* will burn off any of the soot on the DPF filter. Temperatures lower will not. According to the CTS2 in my truck, average temps run from 500-600* with normal driving even on longer trips of 100 or more miles. At these temps, the % of soot continues to rise, not go down.

The 2011 - 2016 6.7 PS triggers a regen at 500 miles regardless of how full the DPF is. The other clarification (as posted by Kodiak above) is that during a regen, fuel is dumped into the cylinder during the exhaust stroke and ignited at the DPF filter to raise the temperature of the filter so it burns the crap out of the filter. Fuel does slip past the rings and into the oil, have Blackstone do an analysis of your oil after your next oil change. Not a whole lot, but some does get through as the oil analysis will show. Using a fuel additive that increases the cetane of your fuel will help get you to the 500 mile automatic regen and will help by shortening your regens. Increasing the cetane increases the temperature of your combustion stroke more thoroughly burning the fuel reducing the crap that gets caught in the DPF.

I am one of those that are in the "I wanna know" camp. IMHO if you use your truck as a daily driver which typically includes highway driving, really there is no reason to "worry" about your DPF and regens. However, I'm not in that camp. I'm an old retired guy who uses his truck primarily for short around town trips. Not completing the regens will lead to the "drive until clean" message which always seem to occur when I do have a particular place to go. I prefer to keep tabs on them so that when they start, old guys like me with usually no particular place to go can take a cruise and finish the regen.

The DPF % full screen is bazaar at best. The only time I've ever seen a pattern was when it regened on my ride back to CT from Vermont. It seemed to reduce by 5% a clip and did eventually get to 0. After the regens I've seen it "stick" at 20% for days, then shoot to 40%. I use PM22a which has a slight cetane boost and I usually get into the high 490s when the truck regens.

I was towing my fifth wheel a few days ago with the DPF percentage displayed on my ScanGuage II. The percentage was only around 25 as I'd been towing for several hundred miles and was getting passive regen. At some point the truck started an active regen (confirmed by my ScanGauge) which took me down to low single digits in the DPF percentage in a pretty short amount of time. Obviously I'd hit the 500 mile mark as the 25 DPF percentage at the beginning of the active regen didn't warrant it.

Hi guys so I was looking around oasis in workshop manual and pced for the regen cycles. I couldn't find anything defining regen happening at 500 miles I will post what I did find for you guys to read .

The diesel particulate filter regeneration occurs during normal vehicle operation. The PCM may regenerate the diesel particulate filter at idle. During the diesel particulate filter regeneration, fuel is injected into the cylinder after the main combustion. The extra fuel increases the temperature of the exhaust gas and lights off the OC. The temperature of the exhaust gas increases to greater than 550c (1,022F) at the OC and diesel particulate filter. At this temperature soot burns. soot particulates that may have accumulated on the OC or in the diesel particulate filter are burned and the ash is trapped in the diesel particulate filter. The ash particulates that remain in the diesel particulate filter are mainly comprised of metallic compounds generated during combustion and form corrosion in the exhaust system

Passive regeneration occurs naturally as a result of normal engine operating conditions. During passive regeneration, the exhaust constituents/temperature are at an appropriate level where some soot can be reduced or oxidized (Burned) thus cleaning the filter, Active regeneration, which is initiated by the PCM, will occur when there is not enough passive regeneration occurring due to vehicle driving patterns. In an active regeneration, the DPF is cleaned by raising the exhaust temperature to a point where the soot is burned away. After soot is burned off, the exhaust temperature and back pressure (Restriction) fall back to normal levels.

Recommend if you are going to re-quote something from a Ford document, that you tell people where you are getting it from. In this case, you are just re-quoting the description from the Ford PCED 6.7L Diesel document, which I already provided in post #14.

I dont understand why Ford has this 500 mile regen limit. It makes no sense to me. I have towed my 5th wheel and had it doing a passive regen down to 10% soot and the active regen kicked in and still it lasted almost 30 minutes. I dont understand why it wouldnt be a shorter time like 5 minutes if it can burn from 100% to 5-7% in 20-30 minutes. Is there a logical reason why they cant have it programmed to regen at 100% and let the miles go as long as you are under 100%?