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So, this may sound dumb, but can someone explain to me how these trucks regen? I came to Ford from several years of Duramax trucks. In my Duramax, when it went into a regen, it would idle about 400 RPM higher and had a change in the exhaust note (along with a burning smell).
The other day, I got home from work and it smelled like my Super Duty was on fire. I assume it was in a regen, but I had no other indication of it. Are there indications that I missed (maybe a message on the dash)? I looked in the manual and saw it talking about passive and active regen and so forth, but it was kinda confusing.
How does it regen (my Duramax had an injector in the exhaust pipe)?
I'm hoping you all can explain all this to me. Really trying to learn all I can about these trucks. Thanks.
The goal of 'regeneration' is to burn off particulate matter trapped in the diesel particulate filter (DPF) of the exhaust system by using extreme heat.
Active Regeneration occurs when sensors before and after the DPF measure a buildup of particulates inside the filter matrix which are beginning to restrict exhaust flow. Once a threshold is reached, an active regeneration will commence by injecting diesel directly into the exhaust system.
The big difference between the Ford and the D-max is that Ford does not use the extra injector in the exhaust system. Instead, during the exhaust stroke of the engine (when the exhaust valves open to dump the burned combustion gasses down the exhaust pipe), extra fuel is injected and flows down the exhaust system. The fuel combusts either along the way to or at the DOC. The D-max injector is right before the DOC...so two ways of accomplishing the same thing. The DOC (diesel oxidation converter) is basically a catalytic converter for diesel engines which serves to increase heat.
The 2017 Ford, unfortunately, gives no warning or messages or indicators that an "active regeneration" is occurring. Previous generations would warn that an active regeneration had started, although they would never tell when one was completed.
Passive regen is the same as on a Duramax or Cummins. When towing a very heavy load, working the engine hard, exhaust gas temps may reach high enough temps to burn off particulates trapped in the DPF without injecting any additional diesel fuel. This is a natural process and requires no electronic intervention.
During and immediately after an active regen, the truck will smell like its on fire. A brand new truck experiencing its first few regens will smell worse than one that has already had 5 or 10 regens. It kind of breaks-in like the motor. Don't park on or near combustibles during or right after a regen.
Idle speed does not change during regeneration, but the engine has a slightly different tone if you listen for it. The turbo boost gauge becomes much more responsive during an active regeneration - more boost than usual is applied to help compensate for any power loss. Watching the gauge is one way to tell if a regen is occurring. Finally, fuel economy will drop considerably, as obviously extra fuel is being used.
Active regens will pause while stopped in traffic, and re-start automatically once you get moving above 4mph again.
I know when mine is in regen, I can definitely smell it and I hear a fast ticking sound underneath the truck, is this the DEF injector? as regen comes to an end, the ticking slows down and then stops.
Your explanation has no mention of DEF. How does that come into play? Thanks!
DEF has nothing to do with the regeneration process. If you recall, the 6.4L Ford diesel trucks had to perform regenerations but did not use DEF. Same with the cheating VW diesels to current (2.0L) and even the Cummins 6.7L for awhile.
DEF is basically 33% ammonia and 67% purified water. It has a separate tank, an electric pump, and an injector (called a dosing module). Because of the high water content, it can freeze around 12F and therefore the tank, pump, and DEF delivery hoses are all heated.
DEF is injected into a section of the exhaust system (typically between the DOC and DPF on our Ford pickups) called the SCR (selective catalyst reduction) module. Inside, there is a spiral mixing tube. The dosing injector sprays the DEF in just ahead of the spiral where it mixes with the hot exhaust gases. The DEF reacts with the high nitrogen oxide (NOx) content in the exhaust and converts it to nitrogen, water, and CO2. NOx is bad for humans and the environment, and it is the high amounts of tailpipe NOx which got VW into trouble. SCR through the use of DEF is very effective at reducing NOx. Only a small amount of CO2 is released by a diesel even after SCR treatment.
So basically, the DEF is strictly an emission control. A full tank (7.4 gallons on our new 2017 trucks) should last at least an oil change. Higher engine demand (pulling, hauling, etc) results in higher DEF consumption.
Your explanation has no mention of DEF. How does that come into play? Thanks!
DEF is injected into the exhaust (I think after the DPF) to reduce NOx (nitrous oxides) emissions. It has nothing to do with the soot.
Originally Posted by PwerStroke99
I know when mine is in regen, I can definitely smell it and I hear a fast ticking sound underneath the truck, is this the DEF injector? as regen comes to an end, the ticking slows down and then stops.
That ticking is just the heat causing expansion (and then the cooling causing contraction after the regen stops) of the metal.
I know when mine is in regen, I can definitely smell it and I hear a fast ticking sound underneath the truck, is this the DEF injector? as regen comes to an end, the ticking slows down and then stops.
You know how a hot engine ticks after you shut it off, after say driving up a mountain and it is good and hot? You're hearing the ticking from the DPF tube under the truck. As it cools, it will stop ticking, like an engine.
Each time shortly after you shut your truck off, you will hear a couple of clicks and whirrs from underneath. The DEF pump runs in reverse after each shut-down to pump all the DEF out of the lines back into the tank to prevent possible freeze issues...even in the summer. It doesn't know how cold it will get at night, lol.
DEF has nothing to do with the regeneration process. If you recall, the 6.4L Ford diesel trucks had to perform regenerations but did not use DEF. Same with the cheating VW diesels to current (2.0L) and even the Cummins 6.7L for awhile.
DEF is basically 33% ammonia and 67% purified water. It has a separate tank, an electric pump, and an injector (called a dosing module). Because of the high water content, it can freeze around 12F and therefore the tank, pump, and DEF delivery hoses are all heated.
DEF is injected into a section of the exhaust system (typically between the DOC and DPF on our Ford pickups) called the SCR (selective catalyst reduction) module. Inside, there is a spiral mixing tube. The dosing injector sprays the DEF in just ahead of the spiral where it mixes with the hot exhaust gases. The DEF reacts with the high nitrogen oxide (NOx) content in the exhaust and converts it to nitrogen, water, and CO2. NOx is bad for humans and the environment, and it is the high amounts of tailpipe NOx which got VW into trouble. SCR through the use of DEF is very effective at reducing NOx. Only a small amount of CO2 is released by a diesel even after SCR treatment.
So basically, the DEF is strictly an emission control. A full tank (7.4 gallons on our new 2017 trucks) should last at least an oil change. Higher engine demand (pulling, hauling, etc) results in higher DEF consumption.
Thank you very much...I have now learned my "one new thing" for the day. Cheers!
Do not park or idle your vehicle over dry leaves, dry grass or other combustible materials. The
regeneration process creates very high exhaust gas temperatures and the exhaust will radiate a considerable amount of heat during and after regeneration and after you have switched the engine off. This is a potential fire hazard.
Note: During regeneration at low speed or engine idle, you may smell a hot metallic odor and could notice a clicking metallic sound. This is due to the high temperatures reached during regeneration and is normal.
Note: Changes in the engine or exhaust sound may be heard during the regeneration process.
The diesel particulate filter on your vehicle requires periodic regeneration to maintain its correct function. Your vehicle will carry out this process automatically.
If your journeys meet one of the following conditions:
• You drive only short distances.
• You frequently switch the ignition on and off.
• Your journeys contain a high level of acceleration and deceleration.
You must carry out occasional trips with the following conditions to assist the regeneration process:
• Drive your vehicle in more favorable conditions, which you will find at higher vehicle speeds in normal driving, on a main road or freeway for a minimum of 20 minutes. This drive may include short stops that will not affect the regeneration process.
• Avoid prolonged idling and always observe speed limits and road conditions.
• Do not switch the ignition off.
• Select a suitable gear to ideally maintain engine speed between 1500 and 3000 RPM.
Your vehicle has a diesel particulate filter. The diesel particulate filter is an inline filter in the exhaust system that reduces carbon emissions by trapping exhaust particles before they reach the tailpipe. The diesel particulate filter looks similar to a traditional exhaust catalyst and is part of the exhaust system under your vehicle. The filter couples to a diesel oxidation catalyst that reduces the amount of harmful exhaust emitted from the tailpipe. As soot gathers in the system, it begins to restrict the filter. The system must periodically clean the soot that gathers inside the filter. This is carried out in two ways, passive regeneration and active regeneration. Both methods occur automatically and require no actions from the driver. During either one of these regeneration methods, although you may notice a change in exhaust tone. At certain times, the information display shows various messages related to the diesel particulate filter.
Passive Regeneration
In passive regeneration, the exhaust system temperature and constituents automatically clean the filter by oxidizing the soot. Cleaning automatically occurs during normal vehicle operating conditions due to driving patterns.
Active Regeneration
Once the diesel particulate filter is full of exhaust particles, the engine control module commands the exhaust system to clean the filter through active regeneration. Active regeneration requires the engine computer to raise the exhaust temperature to eliminate the particles. During cleaning, the particles convert to harmless gasses. Once cleaned the diesel particulate filter continues trapping exhaust particles.
The regeneration process operates more efficiently when you drive your vehicle at a constant speed above 30 mph
(48 km/h) and at a steady engine speed for approximately 20 minutes. The frequency and duration of regeneration fluctuates by how you drive your vehicle, outside air temperature and altitude. For most driving, regeneration frequency varies from 100–500 mi (160–805 km) between occurrences and each occurrence lasts 9–35 minutes. You can usually reduce the duration of regeneration if you maintain a constant speed above 30 mph (48 km/h).
When the engine control module detects that the diesel particulate filter is nearly full of particulates and you are not operating your vehicle in a manner to allow effective automatic regeneration, messages appear in the information display as a reminder for you to drive your vehicle in order to clean the diesel particulate filter. If you drive your vehicle in a manner to allow effective automatic regeneration, the information display shows a cleaning exhaust filter message, which is the normal regeneration process. You can also choose operator commanded regeneration to clean the exhaust system at this point.
