Diesel Engine Misbehavin'

[DRussell]

The air intake is within the hood. There was a ring of ice? Snow? Melted and refrozen snowflakes? Something... inside the air filter housing. But I doubt that was the problem, as the problem came back after blowing it out. I still haven't ruled out that it was just an issue that the filter needs to be changed... because I haven't operated with a new filter yet. Sure, I blew the visible stuff out of the filter housing, you know... the typical little bit of bugs, dust n stuff that you find in any air filter housing... but it's harder to tell if the element itself has collected enough microscopic stuff to be an issue. A its been long enough since an air filter change that I'm just doing that pro forma.

This Mahindra has a unique exhaust treatment (as I'm told by their website) that does convert emissions to water and carbon dioxide; which would explain the little bursts of steam that I see out of the exhaust in cold weather... as opposed to the tractor actually sucking in snowflakes or a wet air filter from melting snowflakes...

Maybe it does get a little overloaded when the engine isn't running full bore? Not sure. I've been going by the temperature gauge. One thing that I try to do is... when I start the tractor in the winter, I never shut if off until it has gotten up to operating temperature. And often, it has to sit and run for a little while in cold to get the hydraulics working right, otherwise the hydraulic clutches are super slow to get the darn thing moving when you shift gears.

Maybe I should horse it during these warm up periods, instead of running at 1500RPM?

Maybe I should, as you say... work it like a rented mule... once in a while... never seem to have these issues in the summer; when it's 85F and I'm mowing or baling hay at 2000 RPM for hours at a rip.

I owe a couple of guys here pictures of the exhaust treatment setup and a reply as to how I made out.

According to the forecast, looks like I'll have an update towards the end of the week; as I'll need to get out and move a bunch of snow again.

What is PTO speed on it?

Maybe I'm completely off my rocker, but my point is that I find it hard to believe it's not getting warm enough for emissions equipment, or like Barnyard is saying, a modern form of wet stacking after working moving snow for 3-4 hours at 1800 RPM or even 1500 RPM. (1800 RPM is wide open on my Case 1030 diesel, which I know is a lower speed engine but still.)

 

[Steve in IL]

The air intake is within the hood. There was a ring of ice? Snow? Melted and refrozen snowflakes? Something... inside the air filter housing. But I doubt that was the problem, as the problem came back after blowing it out. I still haven't ruled out that it was just an issue that the filter needs to be changed... because I haven't operated with a new filter yet. Sure, I blew the visible stuff out of the filter housing, you know... the typical little bit of bugs, dust n stuff that you find in any air filter housing... but it's harder to tell if the element itself has collected enough microscopic stuff to be an issue. A its been long enough since an air filter change that I'm just doing that pro forma.

This Mahindra has a unique exhaust treatment (as I'm told by their website) that does convert emissions to water and carbon dioxide; which would explain the little bursts of steam that I see out of the exhaust in cold weather... as opposed to the tractor actually sucking in snowflakes or a wet air filter from melting snowflakes...

Maybe it does get a little overloaded when the engine isn't running full bore? Not sure. I've been going by the temperature gauge. One thing that I try to do is... when I start the tractor in the winter, I never shut if off until it has gotten up to operating temperature. And often, it has to sit and run for a little while in cold to get the hydraulics working right, otherwise the hydraulic clutches are super slow to get the darn thing moving when you shift gears.

Maybe I should horse it during these warm up periods, instead of running at 1500RPM?

Maybe I should, as you say... work it like a rented mule... once in a while... never seem to have these issues in the summer; when it's 85F and I'm mowing or baling hay at 2000 RPM for hours at a rip.

I owe a couple of guys here pictures of the exhaust treatment setup and a reply as to how I made out.

According to the forecast, looks like I'll have an update towards the end of the week; as I'll need to get out and move a bunch of snow again.

Perhaps I’m old fashioned, but for my winter plow tractor, I remove the tube that sucks intake air from in front of the radiator (having it suck engine heated air from under the hood), and I put a piece of cardboard in front of about half of the radiator. Using a remote thermometer, I find this increases the engine intake air to about 50-60 degrees. Perhaps that might help you?

 

[will-max dairy]

Perhaps I’m old fashioned, but for my winter plow tractor, I remove the tube that sucks intake air from in front of the radiator (having it suck engine heated air from under the hood), and I put a piece of cardboard in front of about half of the radiator. Using a remote thermometer, I find this increases the engine intake air to about 50-60 degrees. Perhaps that might help you?

The tractor has an intake manifold heater that activates with the key... You turn the key on and pause... a little heater element light comes on the dash (this light still works)... you hear a click, the light goes off... then you start the tractor.

I would imagine that the intake air (at the engine) is plenty warm enough after using that to start the tractor, letting it run to warm up the hydraulics... and then working it at 1800RPM for a few hours to move snow at 25F. But... at the air intake itself? Don't know... I would imagine that the various screens on the hood and such keep snowflakes and most powdery snow out...


Right now I'm thinking...either...

Air filter needed changing, and a little bit of obstruction of the screens/housing from snow/ice was just enough to set off a low intake air sensor...
OR
Coolant got low, tractor derated... needed a few start up/shutdown cycles and movement to "burp" an air bubble out of the system.
OR
Needs a shut off/turn on cycle every little while in the winter so that it can do a little extra exhaust processing (again...whatever that is, since it's not a "regen"...)


To answer DRussell's question. The tractor has a two speed PTO. You can run the PTO at high speed "economy" and get 540PTO RPM at 1500 engine RPM. I use this in the summer to run the haybine. A 7' haybine isn't a big load, and I can mow hay for hours with just a leeeeetle bit of diesel. I tried it for baling, but I didn't like how the transmission sounded while working the plunger... and elect to use normal setting... 540PTO RPM at 2000 engine RPM for baling... to get more help from the engine's flywheel running the baler's plunger.

My take is that the tractor should be perfectly fine running at 1500RPM, unless you are really depending on the engine's flywheel... which... when you scalp some dirt under the snow?... or hit a big pile of snow with the loader?... maybe I should be running at 2000 for the most stored flywheel energy...

 

[cumminstinkerer]

I tried explaining some of how a DOC system works but you all missed a bunch of it, most all newer diesels, including you pickups function basically the same way, They have to have the absolute snot worked out of them from time in order for the exhaust to reach proper temps, Will you are also fighting DEF that is too cold and possibly frozen in the DEF header or lines, once you rev it up you are getting into the realm of where it is ready to actually inject the DEF and since it is likely still frozen, not sure how mahindra deals with keeping the DEF not frozen, it is unable to inject and that is putting you into a limp mode, I would again recommend resolving the issue before it sets a hard Emissions code that cannot be reset by you! I have seen these issues many times on generators and even hydraulic excavators during our lovely Iowa winters!

 

[Steve in IL]

The tractor has an intake manifold heater that activates with the key... You turn the key on and pause... a little heater element light comes on the dash (this light still works)... you hear a click, the light goes off... then you start the tractor.

I would imagine that the intake air (at the engine) is plenty warm enough after using that to start the tractor, letting it run to warm up the hydraulics... and then working it at 1800RPM for a few hours to move snow at 25F. But... at the air intake itself? Don't know... I would imagine that the various screens on the hood and such keep snowflakes and most powdery snow out...


Right now I'm thinking...either...

Air filter needed changing, and a little bit of obstruction of the screens/housing from snow/ice was just enough to set off a low intake air sensor...
OR
Coolant got low, tractor derated... needed a few start up/shutdown cycles and movement to "burp" an air bubble out of the system.
OR
Needs a shut off/turn on cycle every little while in the winter so that it can do a little extra exhaust processing (again...whatever that is, since it's not a "regen"...)


To answer DRussell's question. The tractor has a two speed PTO. You can run the PTO at high speed "economy" and get 540PTO RPM at 1500 engine RPM. I use this in the summer to run the haybine. A 7' haybine isn't a big load, and I can mow hay for hours with just a leeeeetle bit of diesel. I tried it for baling, but I didn't like how the transmission sounded while working the plunger... and elect to use normal setting... 540PTO RPM at 2000 engine RPM for baling... to get more help from the engine's flywheel running the baler's plunger.

My take is that the tractor should be perfectly fine running at 1500RPM, unless you are really depending on the engine's flywheel... which... when you scalp some dirt under the snow?... or hit a big pile of snow with the loader?... maybe I should be running at 2000 for the most stored flywheel energy...

The intake air heater you’re speaking of is only used at startup. The intake air solution I’m mentioning is about feeding the engine some warmer air during regular operation. It’s a trick from my time running on highway engines north of Edmonton.

 

[will-max dairy]

The intake air heater you’re speaking of is only used at startup. The intake air solution I’m mentioning is about feeding the engine some warmer air during regular operation. It’s a trick from my time running on highway engines north of Edmonton.

Right.
The electric heater is just for startup. During operation, the intake manifold is designed to use engine/exhaust heat to warm up intake air.

This is definitely not sufficient on an engine running at highway speeds north of Edmonton, ... but it should be sufficient on a slow moving tractor at 25F. If not... there is a design flaw, in my eyes... I shouldn't be needing arctic circle countermeasures at 25F.

 

[DRussell]

Right now I'm thinking...either...

Air filter needed changing, and a little bit of obstruction of the screens/housing from snow/ice was just enough to set off a low intake air sensor...
OR
Coolant got low, tractor derated... needed a few start up/shutdown cycles and movement to "burp" an air bubble out of the system.
OR
Needs a shut off/turn on cycle every little while in the winter so that it can do a little extra exhaust processing (again...whatever that is, since it's not a "regen"...)

I tend to agree. I'm thinking it's a one-off situation like you mention.
Will low coolant cause deration on the Mahindra?

My personal opinion, FWIW, I'd go with the shut off/turn on cycle for the extra exhaust processing.

 

[will-max dairy]

I tried explaining some of how a DOC system works but you all missed a bunch of it, most all newer diesels, including you pickups function basically the same way, They have to have the absolute snot worked out of them from time in order for the exhaust to reach proper temps, Will you are also fighting DEF that is too cold and possibly frozen in the DEF header or lines, once you rev it up you are getting into the realm of where it is ready to actually inject the DEF and since it is likely still frozen, not sure how mahindra deals with keeping the DEF not frozen, it is unable to inject and that is putting you into a limp mode, I would again recommend resolving the issue before it sets a hard Emissions code that cannot be reset by you! I have seen these issues many times on generators and even hydraulic excavators during our lovely Iowa winters!

I got all of it.

What doesn't apply in my case is DEF (Diesel Exhaust Fluid). The Mahindra system uses no DEF.

 

[BarnyardEngineering]

I got all of it.

What doesn't apply in my case is DEF (Diesel Exhaust Fluid). The Mahindra system uses no DEF.

You said it uses some kind of fluid... right? Odds are it is very similar in principle and function to a typical DEF system.

Heck I would not put it past Mahindra to be so arrogant as to claim their fluid is "special" and you can only use their fluid, when it's just plain old Blue DEF.

 

[will-max dairy]

You said it uses some kind of fluid... right? Odds are it is very similar in principle and function to a typical DEF system.

Heck I would not put it past Mahindra to be so arrogant as to claim their fluid is "special" and you can only use their fluid, when it's just plain old Blue DEF.

No... no fluid for exhaust... only fluid levels that I checked are coolant and oil. The Mahindra website for their mCRD emissions control system specifically says... "no DEF" (Diesel Exhaust Fluid) and "no DPF" (Diesel Particulate Filter) and "no regen"...(there is nothing in the manual that says that you need to run x RPMs for y amount of time during operation to get exhaust temperature up)

But... it does do some kind of momentary (about 15 to 30 seconds) cooking (for lack of a better term) of the exhaust system when you shut it off... I'm still at a loss for what goes on during that process. I haven't really seen good documentation on it (yet). I may be down to looking at the fuse/relay names and tracing them to the exhaust to figure out where they go and what they do... Their website says something about their "30 million dollar investment" to come up with a user friendly exhaust gas emissions processing system.... maybe they don't want to talk about it much, to preserve their little trade secret? I don't know...

I owe some people here an update on that, just to satisfy mine and their curiosity...

I might have to do like our old friend JMOR here... and try to sketch the various diesel emissions conditioning options on paper, and post the sketch...

I got a mechanical pencil, and I'm not afraid to use it.. lol

 

[Texasmark]

So...

Mahindra calls this their mCRD system with a DOC (Diesel Oxidation Catalyst). The Mahindra website offers quite a bit of information about why this is more cost effective than typical modern systems that use DEF (Diesel Exhaust Fluid); and say that the DOC does not need regen cycles...

But, it seems that this is maybe a play on words; because whatever goes on after shutdown is some kind of heating of the exhaust system to clean something... maybe it's not a "regen"... but it's a needed process.

mCRD Technology - Mahindra Canada

Does mcRD save you time & money? The answer is YES! A DPF left unchecked will collect soot and ash – resulting in damaging or destroying the filter, reduced performance, unwanted repair costs and unscheduled downtime. But not with mCRD; you get better fuel efficiency and lower maintenance costs...

www.mahindracanada.ca

Since you are an electronics engineer, you know your way around schematics and wiring diagrams. Why don't you find the wires that conduct power to the circuits that are annoying you and scab in a bulb on/near your dash to answer your question about what happens and when? I have a pretty diverse background and I'm not the least bit timid about adjusting OEM or adulterated OEM equipment changes to suit what suits me. Good luck.

 

[will-max dairy]

Since you are an electronics engineer, you know your way around schematics and wiring diagrams. Why don't you find the wires that conduct power to the circuits that are annoying you and scab in a bulb on/near your dash to answer your question about what happens and when? I have a pretty diverse background and I'm not the least bit timid about adjusting OEM or adulterated OEM equipment changes to suit what suits me. Good luck.

It's under warrantee for another 500 hours, until 2000 hours. So I will only do non-invasive metering and such... reading codes...

I'm not opposed to calling out the dealer, if I get to a brick wall. But... I'm also in the process of setting myself up to know this machine, for the years after it passes 2000 hours and everything becomes up to us to take care of. So... a little bit of thrashing and studying is OK... as long as I can get it to run when I need it.

But yes. Thanks for the luck. I might need it.

 

[will-max dairy]

I'm going to be off of here for a while... I get hyperfocused on answering questions and such... it becomes almost debilitating.

I will report back on what I find with the Mahindra, probably next week.

Cheers.

 

[cumminstinkerer]

that being the case will i apologize, I have not heard of anyone getting the no DEF stuff to work, I knew Kubota was working on it about 4 years ago but were still having issues meeting EPA regs, I will have to do some research and see what I can find out! I dont agree with all the DEF EPA crap anyway so!!!! I'll just stop there! Have a great rest of your day.

 

[jon f mn]

A lot of talk on a Def system, but the most common cause of lack of power in a diesel, especially in the winter, is fuel filters. Don't waste any time on anything else til you change the fuel filters and add quality anti gel. For anti gel I only recommend Howes diesel treat. It is by far the favorite of truck drivers and it's them who's life depends on anti gel.

 

[will-max dairy]

Any chance you can upload a picture of the exhaust system on the tractor?

DRussell

I found the diagram of the emissions system in the manual. If you look just a little right of dead center in the photo, you'll see "Electric EGR Valve" to my knowledge, this is the only component that is being driven by the Engine Control Unit. ECU)

In the manual section about it, it says that it is a little motorized valve.

This could be what's going on when I shut off the tractor. The little valve could be activating to perhaps to treat any leftover, recirculated exhaust or crankcase gases. So, there are no lies detected in Mahindra's statements about "no regen" ... "no Diesel Particulate Filter" and "No Diesel Exhaust Fluid."

As far as "Check Engine" goes, if I look at the ECU block in the diagram, at the bottom, there is a "Diagnostic Lamp" and "Malfunction Indicator Lamp." According to the map of dashboard indicators in the manual:

The "Diagnostic Lamp" is the "Check Engine" indicator on the dash. The manual says that this lights for any sensor malfunction, other than emissions... and it just says... to have a dealer check the tractor when it comes on. If I look at the diagram, this could be activated by something like the fuel metering sensor, I suppose.

The "Malfunction Indicator Lamp" is a different indicator on the dash. The manual says that this is reserved for emissions problems only.

As for my problem with the engine failing to operate at full power, the diagnostic flow chart in the manual lists issues with the fuel filter and fuel as the first three items in this list.

Here is where I have to admit to being overdue on some maintenance.

The maintenance chart at the end of the manual has a few things that piqued my interest in my current situation..
It says...

To drain water from the fuel filter assembly every 15 days (I never do that, only when I change the filter). The "water in fuel" indicator on the dash is not lighting, but I really don't trust individual indicators on this thing. Some of the other indicators on the dash (like the 4wd and Park indicators) don't light when I know they should light, due to chintzy wiring to the sensors.

To change the fuel filter every 250 hours, more often if needed. I thought 500 hours... and this one is on about 750. So a new fuel filter is a given.

The engine just went over 1500 hours, and there is one new item that comes up at 1500hours, that is the Positive Crankcase Ventilation (PCV) oil separator. If you look at the picture, the crankcase gases are fed to the turbocharger input, through this oil separator. This separator has a drain on it (which I assume lets any separated oil drip out) and it has a filter (separator). This filter is due to be changed every 1500 hours. This is a new notion for me, as this is my first turbo-charged tractor. I need to check this, as it would be the equivalent of a "plugged PCV" on your gas car engine.

I'm not used to tractor engines having car engine problems.

Other than that, according to the maintenance schedule, I'm OK with oil changes, oil level, oil filter changes, coolant level, air filter, etc, etc.

Making a trip to the dealer this AM, after chores to grab some filters. And then checking on these items this afternoon.

PS. I have the "Owner's Manual" for this tractor, and I bought the "Service Manual" in digital format. As for figuring out any codes from the ECU... the "Service Manual" says to connect the Mahindra diagnostic tool and refer to the "Diagnostic Manual"... of course... there is another manual, that I don't have... ugh... The Service Manual is loaded with information about tearing down and re-building all of the mechanicals in the machine. Nothing on the ECU or diagnostics.

 

[Bob Bancroft]

DRussell

I found the diagram of the emissions system in the manual. If you look just a little right of dead center in the photo, you'll see "Electric EGR Valve" to my knowledge, this is the only component that is being driven by the Engine Control Unit. ECU)

In the manual section about it, it says that it is a little motorized valve.

This could be what's going on when I shut off the tractor. The little valve could be activating to perhaps to treat any leftover, recirculated exhaust or crankcase gases. So, there are no lies detected in Mahindra's statements about "no regen" ... "no Diesel Particulate Filter" and "No Diesel Exhaust Fluid."

As far as "Check Engine" goes, if I look at the ECU block in the diagram, at the bottom, there is a "Diagnostic Lamp" and "Malfunction Indicator Lamp." According to the map of dashboard indicators in the manual:

The "Diagnostic Lamp" is the "Check Engine" indicator on the dash. The manual says that this lights for any sensor malfunction, other than emissions... and it just says... to have a dealer check the tractor when it comes on. If I look at the diagram, this could be activated by something like the fuel metering sensor, I suppose.

The "Malfunction Indicator Lamp" is a different indicator on the dash. The manual says that this is reserved for emissions problems only.

As for my problem with the engine failing to operate at full power, the diagnostic flow chart in the manual lists issues with the fuel filter and fuel as the first three items in this list.

Here is where I have to admit to being overdue on some maintenance.

The maintenance chart at the end of the manual has a few things that piqued my interest in my current situation..
It says...

To drain water from the fuel filter assembly every 15 days (I never do that, only when I change the filter). The "water in fuel" indicator on the dash is not lighting, but I really don't trust individual indicators on this thing. Some of the other indicators on the dash (like the 4wd and Park indicators) don't light when I know they should light, due to chintzy wiring to the sensors.

To change the fuel filter every 250 hours, more often if needed. I thought 500 hours... and this one is on about 750. So a new fuel filter is a given.

The engine just went over 1500 hours, and there is one new item that comes up at 1500hours, that is the Positive Crankcase Ventilation (PCV) oil separator. If you look at the picture, the crankcase gases are fed to the turbocharger input, through this oil separator. This separator has a drain on it (which I assume lets any separated oil drip out) and it has a filter (separator). This filter is due to be changed every 1500 hours. This is a new notion for me, as this is my first turbo-charged tractor. I need to check this, as it would be the equivalent of a "plugged PCV" on your gas car engine.

I'm not used to tractor engines having car engine problems.

Other than that, according to the maintenance schedule, I'm OK with oil changes, oil level, oil filter changes, coolant level, air filter, etc, etc.

Making a trip to the dealer this AM, after chores to grab some filters. And then checking on these items this afternoon.

PS. I have the "Owner's Manual" for this tractor, and I bought the "Service Manual" in digital format. As for figuring out any codes from the ECU... the "Service Manual" says to connect the Mahindra diagnostic tool and refer to the "Diagnostic Manual"... of course... there is another manual, that I don't have... ugh... The Service Manual is loaded with information about tearing down and re-building all of the mechanicals in the machine. Nothing on the ECU or diagnostics.

An air/oil separator is not a new thing, depending on the machine. I have several turbocharged machines, but no air/oil separators that I am aware of. Now having a replaceable filter in one is really interesting! Sounds like you're getting it figured out.

 

[Gene in Mi]

Your Mahindra has Tier 4 emission system. It uses a DOC to clean the exhaust. A DOC is a diesel oxygenating catalyst. Your gasoline car uses a catalyst too. (Maybe call that one a GOC) A DOC does not work well with high sulfur fuel, using a DOC was not possible until low sulfur diesel became available.

 

[will-max dairy]

An air/oil separator is not a new thing, depending on the machine. I have several turbocharged machines, but no air/oil separators that I am aware of. Now having a replaceable filter in one is really interesting! Sounds like you're getting it figured out.

More like a module, I think. I don't know if "filter" is the correct term. Going over to the dealer to pick up some other filters... he's never sold this separator module, but, he says that I'm their first Mahindra 6075 customer, bought ours in 2019. So maybe we're the first to get to this point in the maintenance schedule.

Thankfully, he has one fuel filter left in captivity. Says that everybody decided to buy fuel filters when the weather got cold.

Guilty as charged.

Need to get that one, and get another on hand. 250 hours isn't a long time.

 

[MARK ROBKE]

DRussell

I found the diagram of the emissions system in the manual. If you look just a little right of dead center in the photo, you'll see "Electric EGR Valve" to my knowledge, this is the only component that is being driven by the Engine Control Unit. ECU)

In the manual section about it, it says that it is a little motorized valve.

This could be what's going on when I shut off the tractor. The little valve could be activating to perhaps to treat any leftover, recirculated exhaust or crankcase gases. So, there are no lies detected in Mahindra's statements about "no regen" ... "no Diesel Particulate Filter" and "No Diesel Exhaust Fluid."

As far as "Check Engine" goes, if I look at the ECU block in the diagram, at the bottom, there is a "Diagnostic Lamp" and "Malfunction Indicator Lamp." According to the map of dashboard indicators in the manual:

The "Diagnostic Lamp" is the "Check Engine" indicator on the dash. The manual says that this lights for any sensor malfunction, other than emissions... and it just says... to have a dealer check the tractor when it comes on. If I look at the diagram, this could be activated by something like the fuel metering sensor, I suppose.

The "Malfunction Indicator Lamp" is a different indicator on the dash. The manual says that this is reserved for emissions problems only.

As for my problem with the engine failing to operate at full power, the diagnostic flow chart in the manual lists issues with the fuel filter and fuel as the first three items in this list.

Here is where I have to admit to being overdue on some maintenance.

The maintenance chart at the end of the manual has a few things that piqued my interest in my current situation..
It says...

To drain water from the fuel filter assembly every 15 days (I never do that, only when I change the filter). The "water in fuel" indicator on the dash is not lighting, but I really don't trust individual indicators on this thing. Some of the other indicators on the dash (like the 4wd and Park indicators) don't light when I know they should light, due to chintzy wiring to the sensors.

To change the fuel filter every 250 hours, more often if needed. I thought 500 hours... and this one is on about 750. So a new fuel filter is a given.

The engine just went over 1500 hours, and there is one new item that comes up at 1500hours, that is the Positive Crankcase Ventilation (PCV) oil separator. If you look at the picture, the crankcase gases are fed to the turbocharger input, through this oil separator. This separator has a drain on it (which I assume lets any separated oil drip out) and it has a filter (separator). This filter is due to be changed every 1500 hours. This is a new notion for me, as this is my first turbo-charged tractor. I need to check this, as it would be the equivalent of a "plugged PCV" on your gas car engine.

I'm not used to tractor engines having car engine problems.

Other than that, according to the maintenance schedule, I'm OK with oil changes, oil level, oil filter changes, coolant level, air filter, etc, etc.

Making a trip to the dealer this AM, after chores to grab some filters. And then checking on these items this afternoon.

PS. I have the "Owner's Manual" for this tractor, and I bought the "Service Manual" in digital format. As for figuring out any codes from the ECU... the "Service Manual" says to connect the Mahindra diagnostic tool and refer to the "Diagnostic Manual"... of course... there is another manual, that I don't have... ugh... The Service Manual is loaded with information about tearing down and re-building all of the mechanicals in the machine. Nothing on the ECU or diagnostics.

I agree-it looks like only the EGR is controlled by the ECM. No sensors on the DOC, which in my mind, then it works like a gas engine catalytic converter. As far as the clicking noises after shut down, I suspect the ECM is Cycling the EGR full stroke both ways. Yeah-you really are overdue for a fuel filter, and with the close tolerances of newer fuel injectors, it's real important. And yeah, diagnostic manuals are a separate entity from a repair manual, and probably more needed. Good luck, keep us posted, Mark.