actually regen can be anywhere from 90-630. At about 630 miles is the mandatory backstop where it will regen.

The duty cycle is what determines the regen.

Doing a manual regen in the yard I would think would help as then you will get it completed all at once.

If the truck is in regen and then stops to perform a function and then moves the regen will start up again as it did not get completed. This will happen until enough soot is burned off.

I would suggest you try to do the manual regen in the yard then send the truck out and see if that helps to reduce the constant regens.

 

Dude, this truck had so many manual regens performed on it that it melted the substrate solid on the original DPF. Doing a manual regen doesn't fix anything, because as soon as you're done and it leaves the lot, the truck tries to go into it's own regen again. This is my issue. One would assume if a manual regen is successful, that it would be some time before it needs to be done again.

I hate this stuff so much, I wish I could just rip it off and throw it in the trash.

 

Now I understand. Yes that sucks.

 

A few points:

1. You have one specific truck that has a serious and as yet undiagnosed problem. This is not the fault of the emissions control system that operates just fine on millions of these same trucks, including apparently others in your own fleet.

2. If the vehicle is *operated* as designed there is no issue with the emissions control system.

3. If the vehicle is not *operated* as designed and is instead idles for excessive periods of time as defined by Ford in the owner's maunal diesel supplement, additional actions need to be taken to prevent issues. This includes the use of the Ford approved DPF manual regen controller to perform stationary regeneration operations to compensate for the excessive idle time. It makes no difference whether you are an ordinary consumer or a government agency, the vehicle has specific maintenance requirements.

4. If you are not able to control what the drivers do with the trucks during the day, then your only alternative to ensure proper maintenance of the trucks is to ensure the regens are performed at the lot / service facility on a regular basis. The interval will need to be determined based on the hours and miles that are accumulated on the vehicles daily. This might mean that every vehicle must be manually regen'd when returned to the lot each Friday, or perhaps Wed and Fri. If this is not acceptable and you find no other way to ensure the vehicles are operated within the manufacturer's specifications, your alternative is to replace the trucks with gas engined ones that do not have the idel time limitations.

On the particular problem truck, hopefully the new engine will result in the replacement of the problem component. I'd suggest immediately after you get the engine replaced and the truck operational, you take a snapshot of the operating parameters via IDS and compare them to the operating parameters from a truck not having issues. This could enable you to spot an issue with a sensor or other component that isn't replaced with the engine.

 

Interesting that it's only the one truck....regen as you know is simply a matter of comparing incoming verse outgoing pressure in the DPF....so if you suspect the engine is the issue it would need to running so poorly that it would be noticeable because we need to build those hydrocarbons or soot somehow.

If it's regening to the point of melt down I would be looking to an electrical or programming issue.....if you have a scanner hook up to a good truck and see if you can snapshot the DPF pressure diff and the compare it to the bad truck....for some reason the ECM thinks the DPF is restricted...trust me, this could be something as simple as a poor ground or a slightly cut harness...did you do a voltage drop and resistance test on all those sensor harnesses?

If you want to change the motor go ahead but I would be changing the ECM with one from the good truck first.......

 

The other thing I forgot to ask is: does the PTO idle up work? Because if it's idling under 1200 RPM all day it's going to cold soak and plug the DPF extremely fast.

 

Way ahead of you, PCM from a different truck was subsituted, no change was made, and I assure you, all wiring harness checks, especially from DPF sensor to PCM, were verified, more than once, no opens, shorts to ground or power, no bad ground, etc.

I'm pretty sure it's a base engine issue. If I had saved a session, I could take a screen shot to show IDS data screen when DTC's are saved. From what I can tell, the DPF side is performing normally, it institutes a regen when the sensor hits around 7psi, which is pretty normal operation ( and of course the DPF is genuinley clogged)

 

Yes, it works just fine, and of course, it would have to for the hydraulics to function. As a matter of fact, I used it to rotate the boom out of the way to prepare for cab removal.

Cab is off, (After cutting 600!@$#$#@ Altec wires) and old engine is out on the ground. Will update.

 

tuning in for updates.

 

You report it melted down a DPF, it would seem the only way for that to occur would be if the sensor monitoring the DPF was not reporting the temperature accurately.

As we all know the PCM will shutdown regen or even the entire engine if the temp reported gets to the danger zone of damaging the DPF. Even if there was an issue in the engine dumping fuel, the PCM should still detect the high temp and shut things down.

You indicate the wiring and whatnot has been checked, but have the sensors been replaced? Sometimes a sensor can fail in a less than obvious way and seem to work normally in one range and fail in another.

 

How about the DPF pressure sensor, has that been changed?

 

Yes sir, DPF sensor has been replaced, twice ( thought, hey, maybe the new one was no good) and all 3 EGT temp sensors are new, with the new DPF I just installed.

I am aware that the PCM will shut down the engine if the temp gets above 1200F, that's actually happened to me before when doing a manual regen. I think the substrate just finally had enough of being cleaned, both on the truck, and externally in an outside oven. (This was done 3 times by a local company, who shall remain nameless)

 

Does the oil grow in this engine?

 

What is the temp of the DPF during regen? I did not think it was possible to melt the DPF.

Could it be melting the small passages inside the DPF.

Just thinking.

 

Yes, it did, from being in continous regen. As you know, if the 6.4 gets more than 3 qts overfull, it will start siphoning oil from the PCV tube, and blow it right into the turbo intake, burn that oil, and clog the DPF up even worse. This combined with excessive blowby from the fuel washing down the cylinders and wearing the rings out, is why I am deciding to replace the engine. It had over 30hg on the PCV side, a new engine is around 2.5 hg.