Holey DPF!
05-15-2019, (Subject: Holey DPF! ) 
Post: #1
Holey DPF!
This is the results of the 'Can't win with new injectors in ISC' thread.

I ended up replacing the remaining injectors, tubes, supply lines, etc. Despite my preference, I did not end up doing a delete, for several reasons.

Also, with an old dpf laying around, I thought I'd give it a try and put some holes in it! Shoot me if you like, but I'm 4 weeks out now with 20 3/8" holes in the filter, with the dpf differential pressure reading normally and no regen performed by the ecm since. I have done a parked regen, which as expected, completed very quickly, and made tons of smoke.

What are the pitfalls to this approach? DOT could be nosy and see the bit of soot on the tip of the stack, but otherwise the aftertreatment system is doing it's thing.

I realize that 20 3/8" holes are not going to allow the same volume of exhaust to pass through and some of it must pass through the filter. If so, and it never does a regen except when I force one, will this create an issue down the road?

So far, I'm happy, since I'm coming from a regen every 4 hours or so, and have picked up 1/2 mpg on average.

What say you more experienced folk?
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05-15-2019, (Subject: Holey DPF! ) 
Post: #2
RE: Holey DPF!
Due to the whole even parked regens won't save you sooner or later due to short regens the DPF filter holes will all plug and you will only be breathing through the drilled then say EGR or valve seals go those holes will start to plug. At that point turbo seals pop. At worst it melts pistons/valve due to all the heat of normal runng but not exhaling well.

What you've done is created a temporary bypass of problems that will bite you in the ass sooner or later.
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05-15-2019, (Subject: Holey DPF! ) 
Post: #3
RE: Holey DPF!
Lonestar,

Agreed. However, after $12k into this truck in one year for two dpf cleanings, three $600 tows, new doc, new filter, twice to peterbilt and cummins, 6 injectors and endless stress, all for a truck that does not yet earn me a living, I'll take it for now. I still have an 8-10 hour day at another job to keep me and family clothed and fed, after I run this truck 2-5 hours per day each morning.

I'm not biting back at you, but I'm at the end of my limits with this truck. Everything else about the truck is fine, it's only got 92k miles. It's mechanically sound, was taken care of maintenance-wise. Now I'm at the last stop before a delete and want to do everything I can before I have to go to the delete.

In practice, as the filter clogs, wouldn't it start asking for a regen? Holes or not, wouldn't the pressure differential start to register above 3hpa at some point?

I will be treating this filter as a regular 'maintenance' item, as that has been my life now for the last 18 months. However, if this allows me to be faithful in monitoring it and making a quarterly or biannual cleaning with compressed air, I'll settle with it.

I know the filter will not last forever in this state, but even with a purchase of $2k for a new filter every year or two, it's much easier to figure that as a cost to be expected than the time bomb of tows and cleanings, etc, etc, and no improvement.

I can hear Rawze yelling...fix it right!!

I can only figure that will happen when I get rid of this truck someday.

Thanks for hearing me out!
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05-15-2019, (Subject: Holey DPF! ) 
Post: #4
RE: Holey DPF!
no problem just stating what can happen and will happen down the road. like i said its a way to keep things moving its just not the right way.

And I know what ya mean about expenses i became an O/O in September 100k for CM871 Truck/Trailer/Flatbed Gear and so far 6 new injectors all 4 actuators, fuel shutoff solenoid, "I deleted at first trouble of DPF", replaced all the recommended sensors, new air compressor, new thermostat, all new silicone hoses for heater core/apu system, APU AC Compressor/ACDrier/Alternator/belts/now this week new hoses as i went to use ac and a line blew, 1 new steer after a deer smack, new Magnum Lonestar bumper only $700more than replacing OEM after deer, all new air/elec lines from truck to trailer, new exh manifold gasket and associated bolts and yada yada, this friday will be new windshield/3.70 rear ends/drag link/oil pressure sensor/whatever seals leaking on transmission


after becoming o/o i dont know weather to cry or laugh im still profitable and i have a very healthy personal debt of a few new vehicles/toys. these trucks can drive you insane or down right piss you off but i take the good with the bad i knew the industry can nickle and dime and im dealing with it best i can.
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 Thanks given by: hookliftpete , Waterloo
05-15-2019, (Subject: Holey DPF! ) 
Post: #5
RE: Holey DPF!
whats up hook!

so i'm not trying to have a pissing contest here but i feel your pain even tho i've got way more into my truck then you do.

I'm a noobie o/o bud and shi#t sucks man bitting the bullet like that, 12k isnt terrible compared to others that are having the same issues as you are.

The only damn t2 things i lucked out on with getting my truck, is rawze forum and the great ppl here and second one is i got a cm870.

as lonestar said, as a o/o you dont know sometimes to cry or laugh man. idk him personally but its true to the letter. take the good with the bad n keep moving forward bud.


User's Signature: The creator said " Help your self and I will help you; Protect your self and I will protect you "
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05-15-2019, (Subject: Holey DPF! ) 
Post: #6
RE: Holey DPF!
(05-15-2019 )hookliftpete Wrote:  This is the results of the 'Can't win with new injectors in ISC' thread.

I ended up replacing the remaining injectors, tubes, supply lines, etc. Despite my preference, I did not end up doing a delete, for several reasons.

Also, with an old dpf laying around, I thought I'd give it a try and put some holes in it! Shoot me if you like, but I'm 4 weeks out now with 20 3/8" holes in the filter, with the dpf differential pressure reading normally and no regen performed by the ecm since. I have done a parked regen, which as expected, completed very quickly, and made tons of smoke.

What are the pitfalls to this approach? DOT could be nosy and see the bit of soot on the tip of the stack, but otherwise the aftertreatment system is doing it's thing.

I realize that 20 3/8" holes are not going to allow the same volume of exhaust to pass through and some of it must pass through the filter. If so, and it never does a regen except when I force one, will this create an issue down the road?

So far, I'm happy, since I'm coming from a regen every 4 hours or so, and have picked up 1/2 mpg on average.

What say you more experienced folk?

I have seen guys find that "majic number of small holes" that fools the system into thinking everything is still ok in the past.

Just remember that ----

* There is a soot level counter in the ECU that will eventually become higher than the readings of the DPF and eventually start to give you fits. I.E.> the ECU estimates how much soot buildup there "should be" based on fuel and other engine use, and eventually it will count high enough that it will become mis-matched.

* There is high risk of the DPF /DOC collapsing, or the holes not being quite enough for good exhaust flow. It can cause eventual exhaust restrictions and engine/turbo heat problems and eventual damage.

* The EGR system still needs regular maintenance to prevent fuel mileage and efficiency losses.

* Lastly, your actions towards this DOES NOT CURE THE ACTUAL PROBLEM that is causing whatever repeating DPF and other issues you were having at all. There is still a problem somewhere in the engine and/or its EGR system that has not been fixed, costing you fuel mileage, or some other thing that may eventually cause real engine damage. In other words, DOC/DPF problems are the RESULT of engine and egr problems,.. not the cause. Drilling them out does not cure the "cause".
---

Other than that, I have seen guys do this type of thing and get away with it for a while,.. but most of them resorted to more drastic measures (deleting it properly) before it was eventually over with.


User's Signature: ->: What I post is just my own thoughts and Opinions! --- I AM Full Of S__T!.
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05-15-2019, (Subject: Holey DPF! ) 
Post: #7
RE: Holey DPF!
Rawze and Lonestar,

Warnings appreciated for sure.

As far as the soot counter, can't that be circumvented in Insite? Also, I did think that the filter could collapse. I have another that is nearly new, so not all is lost.

Agreed on the egr system needing kept up with. I know that this is not a forever fix by any means, but being so early on in business, I have to have a break from repairs. Everything profit-wise went into the truck and 7 investors and 1 bank still need to be paid monthly.

I know many others are in the same boat.

As far as other issues beyond injectors and sensors, what could be the cause of excess soot? Fuel pump seems healthy, I don't think I have any air leaks, but I have it on my list to check the intake, etc with pressure.

I'll be curious to see what the results are after the next oil sample.
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05-15-2019, (Subject: Holey DPF! ) 
Post: #8
RE: Holey DPF!
EGR system if not working correctly can circulate more soot back into the cylinder and more than needed exhaust gases causing even more soot production per burn cycle

Oil intrusion be it from exhaust valve seals/turbo seals anything that can put liquid oil into the cooler exhaust stream so that it doesnt burn.

Doser injector being bad and constantly leaking fuel into the exhaust

A sensor throwing a faulty reading but not enough to throw a code IMAP/Exhaust Back Pressure/DPF sensors/EGR sensors/EGR Valve

Exhaust leaks sometimes a tell tale sign of an exhaust leak is an excessive amount of white smoke when it regens during driving its letting enough O2 get into the system and the doser fuel ignites before it gets to its intended destination.

you did injectors so you shouldnt have an injector over fueling.........


and as you said you havent checked really for air leaks i would definately do that.

you can start by checking if you can have someone hold the RPMs up high or if you can run them up with cruise buttons then go around putting soapy water on every point in the system that can come apart

so this means all silicone boots also dont just spray the ends of the boots spray the boots themselves as even though you dont see a hole in a boot doesnt mean air is not penetrating through. just soak every point and use alot of soap in the soap water mix to make sure even the smallest air leaks will show bubbles.

make sure to go from the turbo around the CAC best you can try to get where the CAC core means up with its side tanks best you can then go all the way to where the intake meats up with the head.



another thing if you can just pull the exhaust off the back of turbo and look as far down it as you can to see if theres any oil or fuel trails also inspect the doser injector start the truck let it run for a bit with exhaust disconnected and watch to see if doser injector starts to get wet if it does it needs replacing if not take care of any carbon build up around the nozzle.


thats all i can come up with off the top of my head.
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 Thanks given by: Rawze
05-19-2019, (Subject: Holey DPF! ) 
Post: #9
RE: Holey DPF!
Where do I find the accepted values for what the egr system (valve, etc) should be seeing if I look at in Insite?

Also, is there some sort of list of what various engine components (turbo, fuel pump, exhaust back pressure, egr pressure) should be showing as acceptable values for their functions?

I've looked at many of these things in Insite while at idle as well as monitoring while making test runs, but I don't know what for numbers things like these should be at.

Fortunately perhaps, this engine does not have a doser injector, it injects on the exhaust stroke, nor does it have def.

As this is a 10yr old truck, would it be prudent to replace all silicone boots on the intake rather than checking them?

Thanks for your help!
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