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+--- Thread: DPF filter took a dump (/showthread.php?tid=6251)
DPF filter took a dump - Hush - 06-10-2020
I have been running with my magic plug disconnected, no regens or dpf cleaning for the last 700,000 miles plus. Finally she asked for a regen last year, coincidentally i went through the wolf pass and burned everything out, the regen light went off. That lasted for about 6 months. Then the regen light was coming on and of for about six months.
The spring break up is over and I got my truck home, pulled the doc and dpf filter, the doc looks fine, blew the ash out with my compressor. The dpf filter is a plugged up with ash, I was planning on taking it to a shop to have it cleaned. Problem is , the bottom 2 inches of the dpf is gone, cracked and crumpled. Blew out the exhaust stack. lol Should I just hammer it out completely? And run like that? CASH is tight right now.
Ive heard of people drilling them out before.
I was also using the max mileage fuel borne catalyst for the last 6 months, could that have damaged the dpf filter. I mean, there was zero soot! like NOTHING! I expected coals to fall out when took the filters out, but no, just yellow orange ash.
My question is, with my stock system, no tunes, no nothing, just unplugged magic plug, with a hole in the dpf, will the truck run, or derate?
Also I did a snap test while the filters are off and the truck was cold, barely any smoke.
Its a isx cm871 with 1,300,000 miles on it, 700,000 of which where imap sensor unplugged.
RE: DPF filter took a dump - Rawze - 06-10-2020
At 1.3 million miles on the engine, you should be concerned about a whole lot more than just that DPF.
* did anyone do the rod and main bearings when it had 800k or so miles on it?. if not, your driving a ticking time bomb at this point ready to send a piston thru the block with absolutely zero warning , just thought you should know.
* Driving with the magic-plug unplugged the engine has been in a 10% derate that whole time. You likely have driven it so long like that, you never noticed it.
* Do you have a boost gauge on it? Pyro? -- If so, you would have seen this derate on the boost gauge and pyro would have told you turbo was running a bit hot all the time.
* Stop using the liquid scam-a-thon cool-aide additive in your fuel. That stuff should be illegal actually. The placebo effect has you in its grip!.
--- You need to decide to axe it or fix it...
* Axing it requires re-programming of the ecm. For the CM871 ... This is nowhere nearly as difficult or expensive as one would think, as the proper programming and all software tools needed for this is on the internet for free. All a person needs is basic computer skills, their own datalink adapter (inline or nexiq adapter) and the capacitance to sit down and follow the guide.
* Fixing it -- would require replacing both the DOC and DPF at this point if they are more than 500k miles old. Also, if the engine is that old, most of that ash is likely from the thing burning a bit of oil. This means the only way to keep it happy would be a proper inframe on the engine too.
Either way, you have pushed that engine well past its prime and if those bearings were not done, you need to shut it down and inframe it even if you do decide to de-mandate it.
those are my own thoughts on it any ways.
RE: DPF filter took a dump - Hush - 06-10-2020
Hi Rawze thank you for the response.
The rods and bearings where replaced at 850,000 miles, among many other things.
Recently a brass fitting broke in the fuel pump, I had to tow it to a shop in ND. They had a hell a time finding the problem. They checked the injectors and compression and they where surprised how good everything worked.
Everyone though I'd blown the motor up.
Turned out to be a simple fitting.
Also the motor was running extremely rough, I spend a fortune on shops diagnosing the problems, with no results. I was ready to rebuild it, as I thought it might blow up at any hill. The way it sounded.
Believe it or not, uses ½ gallon of oil per 25,000 miles.
Well, I found the problem couple of months ago that changed my view of the engine. I had a bad u-joint. Lol. Somehow everyone was missing it, a spontaneous out of desperation stop at Love's found the problem.
Point is, the engine is smooth! Incredible SMOOTH. The whole time the rough running and the noise was from the bad u-joint and not the engine.
So I decided to go for 1,600,000 miles.
I have a boost gauge, and two pyrometers, lol. With the magic plug unplugged, I am getting 26-28 psi boost on higher elevations and 23-25 on lower elevations. Perfectly usable for me. I drive slow, 62 mph under power.
The pyrometers are for the turbo and the exhaust gas, the turbo has never seen Temps higher than 800 degrees. And this is usually when pulling hills, avarage Temps are 500-600. I also don't shut my truck off until turbo is below 250. I installed a fan switch to force the fan on anytime I want.
The point is I don't have the cash for a brand new filter and doc, due to spending a lot of money on the rebuild driveline and the fuel management system.
I don't want to go completely demandated, as the dpf does an extremely good job of scrubbing the soot out of the exhaust and the passive regens clean it out pretty good. So the plan is to buy a new dpf filter.
But as a stop gap measure, if I hole the dpf, will it further derate?
As after years of driving, I discovered it has two derates, the first one drops it about 10 percent as you pointed out.
On top of this, if any fault happens in the system, who knows what it is, it derates to about 11 psi.
So, I was wondering if anyone did this, hollowed out the dpf and drove with the imap sensor disconnect, did it derate down 11 psi or like usual? Say 26 psi. Or am I missing here?
RE: DPF filter took a dump - Rawze - 06-10-2020
(referring to only the CM871 here. Newer engines are not nearly this forgiving) ...
I have heard of a few guys who have gotten away with a few holes in one, but it has to be done just right or it will see the thing is too "open" and eventually shut you down. It is not the best solution, as you still get reflected heat in the exhaust, fuel mileage will suffer a bit, etc.. but I have seen it done a couple times.
As far as the 1.6 mil ... you did the bottom end, just keep a close eye on the detent clearances on the top end so you do not get a nasty surprise when a valve breaks because the head is completely worn out. DO the overhead valve adjustments every year so you can stay on top of the detent clearance measurement. Seen plenty of people loose their whole enigne over head wearing out and not tracking this.
Ref: http://rawze.com/forums/showthread.php?tid=185&pid=1108#pid1108
and...
http://rawze.com/forums/showthread.php?tid=1106&pid=9466#pid9466
The boost should be around 32 psi in the 10% derated condition. the boost levels you describe sound too low. Maybe pressurize the whole engine up with 30 psi air and find any air leaks including the CAC, EGR piping, etc. - A non-derated engine the boost should be in the 36-37 psi range at max engine load. CM871 with magic plug (egr temp sensor) unplugged, it will usually sit at around the 32 psi mark.
I also hope you have a bypass filter on that thing to keep the soot out of the oil.
I would not suggest you disconnect the IMAP sensor either. Engine uses it for proper fuel air mix and if it cannot see it, you are likely to have bigger problems and power losses. It is enough to unplug the egr temp sensor (magic plug) if your goal is to run it in its factory no-egr / protection engine mode.
Lastly, there is a 'soot counter' in the ecm, so even if you make it look like the dpf is completely free of soot, that counter will eventually count high enough and see the difference getting bigger and bigger from what it wants to see vs what is measured and it will eventually figure out what you did. Just thogut you should know... it is truly easier to re-program the ecm and rid yourself of the headache in the correct ways than to fiddle endlessly with it like you have been.
RE: DPF filter took a dump - Hush - 06-10-2020
Oh, sorry, I meant the egr temp not the imap sensor.
OK thanks for the advice. Not sure what to do though.
As for the boost, it has always been low, even when I bought it, it was barely cracked 32 psi. No idea why.
RE: DPF filter took a dump - Hush - 06-17-2020
Okay, I bought a new dpf filter, looks exactly like my old one. I went to pick it up at the dealer and took my DOC and my old DPF to showed it to the mechanic.
My Doc is in great condition and my DPF would be fine, if the bottom of the filter hadn't cracked. In other words it has no soot what so ever. Just some ash.
I forgot the rules for the forum? Can I post pictures or not? I want to post the old and the new dpf pictures for your comparison.
RE: DPF filter took a dump - Chamberpains - 06-17-2020
Post away my friend.
RE: DPF filter took a dump - hookliftpete - 06-17-2020
(06-10-2020 )Rawze Wrote: (referring to only the CM871 here. Newer engines are not nearly this forgiving) ...
I have heard of a few guys who have gotten away with a few holes in one, but it has to be done just right or it will see the thing is too "open" and eventually shut you down. It is not the best solution, as you still get reflected heat in the exhaust, fuel mileage will suffer a bit, etc.. but I have seen it done a couple times.
As far as the 1.6 mil ... you did the bottom end, just keep a close eye on the detent clearances on the top end so you do not get a nasty surprise when a valve breaks because the head is completely worn out. DO the overhead valve adjustments every year so you can stay on top of the detent clearance measurement. Seen plenty of people loose their whole enigne over head wearing out and not tracking this.
Ref: http://rawze.com/forums/showthread.php?tid=185&pid=1108#pid1108
and...
http://rawze.com/forums/showthread.php?tid=1106&pid=9466#pid9466
The boost should be around 32 psi in the 10% derated condition. the boost levels you describe sound too low. Maybe pressurize the whole engine up with 30 psi air and find any air leaks including the CAC, EGR piping, etc. - A non-derated engine the boost should be in the 36-37 psi range at max engine load. CM871 with magic plug (egr temp sensor) unplugged, it will usually sit at around the 32 psi mark.
I also hope you have a bypass filter on that thing to keep the soot out of the oil.
I would not suggest you disconnect the IMAP sensor either. Engine uses it for proper fuel air mix and if it cannot see it, you are likely to have bigger problems and power losses. It is enough to unplug the egr temp sensor (magic plug) if your goal is to run it in its factory no-egr / protection engine mode.
Lastly, there is a 'soot counter' in the ecm, so even if you make it look like the dpf is completely free of soot, that counter will eventually count high enough and see the difference getting bigger and bigger from what it wants to see vs what is measured and it will eventually figure out what you did. Just thogut you should know... it is truly easier to re-program the ecm and rid yourself of the headache in the correct ways than to fiddle endlessly with it like you have been.
All of this is exactly what I dealt with until I had my isc retuned. It’s no fun, it’s constantly in the background, and your constantly hoping to stay ahead of the filter clogging before it derates...glad that’s over with!
RE: DPF filter took a dump - JimT - 06-17-2020
You'll still want to investigate what might have caused the damage to the original DPF. They don't usually crack or disintegrate for no good reason.