Photos of particulate filter on 6.7L

[Matt400]

I really don't care for all the smoke, I've had several truckers call me to tell me I must have a problem. It really doesn't look good.

And the new ones are suppose to be the new smokeless generation of diesels :-laf

 

[SnoKing]

Great, so it saves it up and then pukes it out. Hope it does not decide to do it during an annual smog test. SNOKING

 

[lklauder]

The shaft coming out of the transmission to the forward U-joint looks to me cantilevered to a degree that could cause vibration or excessive wear. Is that an arrangement with a successful history?



I am also curious if the open channel frame extends all the way to the front. I did not see any picture of that part of it.



Finally, are people likely to put after-market pickup bodies on the CCab?

 

[MCummings]

The DPF sensors require a certain amount of pressure or else they will signal the computer to significantly derate the engine until the problem is corrected. Getting around teh DPF will require more than simply removing it

Are the DPF sensors pressure sensors? are EGT sensors?



What does the DPF sensor require? Equal pressure? Could we mearly loop the two lines together? or space them farther apart in the exhaust?



I'm sure there is a trick to this.



When I get my Six seven, I'll let yall know.



Merrick

 

[Coalsmoke]

Are the DPF sensors pressure sensors? are EGT sensors?



What does the DPF sensor require? Equal pressure? Could we mearly loop the two lines together? or space them farther apart in the exhaust?



I'm sure there is a trick to this.



When I get my Six seven, I'll let yall know.



Merrick

Oh I'm sure there will be a way around it, probably through through a computer overriding module, but it won't be with duct tape and baling twine. According to the Cummins rep, there are 5 sensors, pre and aft pressure, pre and aft EGTs, and the funny thing is I don't remember the 5th one

 

[Mog]

The DPF has to be hot to get it to stay clean inside. So if you run light or no loads all the time it does not get hot enough to get cleaned out. So sometimes it has to shoot fuel into it to get it hot enough. I think on the CAT truck engines they are going to have a coil and spark plug to ignite the fuel so it will have a flame in the exhaust after the turbo to burn out the build up. Also on truck engines over 500hp they will have two DPFs on them. So if you pull heavy loads all the time it should not have to heat up the exhaust.

 

[MontyDyer]

I just received the certification on the new ISB, ISC and ISL, but I sure didnt think the DPF self regen systems were going to be seen on the Dodge applications yet.



As others have mentioned, it is a self cleaning DPF... . with the aid of fuel. There are a couple things that go on here. The DPF uses 3 temperature sensors, and one differential pressure sensor. One at the catalyst inlet, particulate inlet and outlet.



Inside of the DPF is a ceramic honeycomb coated with platinum. When the soot hits the platinum, it creates a chemical reaction that, along with heat and fuel, turns the soot into harmless ash. The ash is then trapped at the rear most portion of the DPF. The the truck goes into a "burn mode" or an active regen, it is having to help the system turn the soot into ash by means of dosing the DPF with fuel. The ash cannot be self cleaned by the DPF and will have to be removed by a special machine. That is why there are V band clamps holding the pieces together to allow off the truck cleaning.



Each manufacturer has there own way of delivering fuel to the DPF. With CAT, they are using a fuel doser block assembly that incorporates an injector mounted into the turbo downpipe along with a sparkplug. With the CATs, the hot fuel will actually be lit off by the sparkplug and have a flame at least a foot down the downpipe. There are various sensors and electronic valves in this system but that covers the major components.



For Mercedes MB906 (will have twin turbos) and 4000 engines, they will also have a fuel doser block assembly that has an injector mounted into the downpipe. However, they are not using a sparkplug. To get there heat, they are using an intake throttle valve; that when needed, will start to close and block a portion of the intake air being delivered, making the exhaust temps rise and aid in the DPF regen.



Cummins will use an injector or nozzle mounted on the downpipe on there ISX engines.



However, on the ISB, ISC, and ISL engines. They are merely using the main fuel injectors in the head to deliver the fuel to the DPF during a stationary regen.

 

[MontyDyer]

I got curious and went to my online notes. Here is a rundown of the system.



The catalyst and aftertreatment diesel particulate filter are made of ceramic material with the chemical coating that is used to oxidize particles of unburned fuel and oil.

The ceramic substrate is held in place in the stainless steel canister by a mat, which is a high-temperature pad that surrounds the ceramic substrate with the metal muffler housing.

The aftertreatment diesel particulate filter captures the particulate matter in the exhaust, and then uses the heat generated by the ratio of the unburned fuel and oil particles in the catalyst to oxidize the particulate matter.



The aftertreatment diesel particulate filter removes soot particles from the exhaust by passing the exhaust gases through a ceramic filter. The soot is oxidized in the filter to form invisible carbon dioxide, giving clean exhaust at the tailpipe. Ash is a by product of oil consumed during normal engine operation. Ash collects in the aftertreatment particulate filter and requires periodic cleaning. This system is designed to decrease the exhaust particulate emissions from the vehicle tailpipe.



The aftertreatment system is monitored by the engine's ECM through the use of exhaust gas temperature sensors and a pressure sensor. The pressure sensor is used to monitor the soot/ash loading of the Cummins® particulate filter to determine if:

1. A regeneration event is needed.

2. Maintenance is needed.

Regeneration is the controlled removal (cleaning) of particulate matter (soot) deposited in the diesel particulate filter. There are three general types of regeneration:

1. Passive regeneration is the continuous regeneration when operating conditions maintain sufficient exhaust temperatures. Soot is continually oxidized in the Cummins® particulate filter to form carbon dioxide. Passive regeneration is totally transparent to the driver.

2. Active regeneration occurs when there is not sufficient heat in the exhaust. Exhaust temperatures are raised by injecting a small quantity of fuel upstream of the diesel oxidation catalyst. The resulting chemical reaction over the diesel oxidation catalyst raises exhaust gas temperature high enough to oxidize the carbon from the filter.

3. Stationary regeneration is the oxidation of soot while the vehicle is not being driven. It is performed because the normal driving cycle will not support passive or active filter regeneration.

A few duty cycles (high idle time and short route segments) will occasionally require a stationary regeneration, such as:

Urban pickup and delivery applications

Emergency vehicle applications

 

[bzingre]

I got curious and went to my online notes. Here is a rundown of the system.



The catalyst and aftertreatment diesel particulate filter are made of ceramic material with the chemical coating that is used to oxidize particles of unburned fuel and oil.

The ceramic substrate is held in place in the stainless steel canister by a mat, which is a high-temperature pad that surrounds the ceramic substrate with the metal muffler housing.

The aftertreatment diesel particulate filter captures the particulate matter in the exhaust, and then uses the heat generated by the ratio of the unburned fuel and oil particles in the catalyst to oxidize the particulate matter.



The aftertreatment diesel particulate filter removes soot particles from the exhaust by passing the exhaust gases through a ceramic filter. The soot is oxidized in the filter to form invisible carbon dioxide, giving clean exhaust at the tailpipe. Ash is a by product of oil consumed during normal engine operation. Ash collects in the aftertreatment particulate filter and requires periodic cleaning. This system is designed to decrease the exhaust particulate emissions from the vehicle tailpipe.



The aftertreatment system is monitored by the engine's ECM through the use of exhaust gas temperature sensors and a pressure sensor. The pressure sensor is used to monitor the soot/ash loading of the Cummins® particulate filter to determine if:

1. A regeneration event is needed.

2. Maintenance is needed.

Regeneration is the controlled removal (cleaning) of particulate matter (soot) deposited in the diesel particulate filter. There are three general types of regeneration:

1. Passive regeneration is the continuous regeneration when operating conditions maintain sufficient exhaust temperatures. Soot is continually oxidized in the Cummins® particulate filter to form carbon dioxide. Passive regeneration is totally transparent to the driver.

2. Active regeneration occurs when there is not sufficient heat in the exhaust. Exhaust temperatures are raised by injecting a small quantity of fuel upstream of the diesel oxidation catalyst. The resulting chemical reaction over the diesel oxidation catalyst raises exhaust gas temperature high enough to oxidize the carbon from the filter.

3. Stationary regeneration is the oxidation of soot while the vehicle is not being driven. It is performed because the normal driving cycle will not support passive or active filter regeneration.

A few duty cycles (high idle time and short route segments) will occasionally require a stationary regeneration, such as:

Urban pickup and delivery applications

Emergency vehicle applications

MontyDyer,

Your explaination is the most correct on the thread. Main difference in Dosing and CRS (Caterpillar Regeneration System) is that Dosing requires an oxidation catalyst and a DPF. CRS requires only a DPF due to aux. heat generation by the spark plug, injector, and combustor canister. The flame front is contained within the canister and is only 7-8 inches long. Controling the aux. heat with CRS allows more consistent DPF temperature and excellent regeneration capability in all applications, even pickup and delivery and high idle applications.

 

[betterthanstock]

I just received the certification on the new ISB, ISC and ISL, but I sure didnt think the DPF self regen systems were going to be seen on the Dodge applications yet.

They couldn't pass EPA without it.



I can't wait to read something like "help, I took a tire iron to my cat, and now the engine won't run, and the dealer wants $3000 for a new one" :-laf

 

[JBee]

No, the DPF is not self cleaning. The engine is equipped with a burn-mode, but you must realize that is meant for burning the accumalted soot, and still leaves a small amount of ash residue. After a while this builds up to the point that the DPF will need to be cleaned.



The DPF sensors require a certain amount of pressure or else they will signal the computer to significantly derate the engine until the problem is corrected. Getting around teh DPF will require more than simply removing it

So I guess we shouldn't be too surprised if they add and "oven cleaning" selection for the exhaust...

 

[jcarey]

I can tell you about that burn mode. The first time it happened I thought I had a stuck injector. It will smoke with a blue white smoke, and do it very heavily. It really shook me up the first time it happened. It smoked for about 15-20 seconds then it quit. It has done it six times in the 9500+ miles I've run the truck. It did it again today on a back road and I stopped just to make sure it wasn't missing any, it wasn't and will not recommend sticking your hand down by the exhaust. It is very hot. A word of caution, if you were in tall grass it would probably set it on fire. I really don't care for all the smoke, I've had several truckers call me to tell me I must have a problem. It really doesn't look good.



Bzingre or MontyDyer,

Any ideas of what is contained in the smoke that EB is talking about. From his description it sounds like the DPF is this creating some emmisions to reduce overall emmisions.

 

[QWaller]

Browsing dieselstop this morning and the word over there is the 6. 4 needs cleanin every 60k and replaced @ $2500 every 120k, could be worse guys.

 

[MCummings]

but, I think emissions warranty is like 10 years and 150,000 miles.



DPF's are gonna be like catylatic converter's in '98 and older cars. A PITA to begin with, but, as technology improves, and aftermarket, you can make power with, or without out them. There will be chips to go either way.





Merrick

 

[PC12Driver]

I was thinking on the way in to work this morning; once the DPF gets cookin' in one of its self-cleaning modes and the temps get up there, what happens if the truck is shut off mid-cycle? Without the exhaust flow to keep the heat in check, wouldn't there be a whole bunch of heat build up in the DPF? I suppose it's been thought of, but that heat has to go somewhere.

 

[Matt400]

what happens if the truck is shut off mid-cycle? Without the exhaust flow to keep the heat in check

The horn goes off and the parking lights flash until you turn the key back on... sorry couldn't resist :-laf

 

[PC12Driver]

The sad thing is... that wouldn't surprise me.

 

[Mhannink]

im sure there will be a way around it just like you can buy dummy O2 sensors for your gasser cats to fool the computer you will be able to get dummy sensors for your dpf

 

[terrywerm]

With the CATs, the hot fuel will actually be lit off by the sparkplug and have a flame at least a foot down the downpipe.

WHOA!! ROCKET BOOSTERS!! :-laf

 

[EMD-Run8]

She can't take any more Captain!!!!!!!