1550 Degree Regen

[Powder Extreme]

A few observations on a regen cycle:



1. It DOES happen during in town driving. This morning I drove for 5 miles of highway followed by 10 minutes of in town, ending with 25 miles of highway.

On the highway the regen started, it was running mostly 12-1400 degrees (thermocouple mounted pre turbo between #1 and #2 cylinders) Once I got to town it stayed between 1000 and 1200, normally it would be 5-700. Sitting at a stop light for just over a minute, it didn't drop below 1100 degrees.



I know it supposedly doesn't happen below 30 mph, but my findings totally contradict that. Either the 30mph part is wrong, or my truck is malfunctioning.



2. It gets HOT, really HOT. I drove for 5 miles straight with it never dropping below 1425, at one point I saw as high as 1550 degrees, but that only lasted for 20 seconds or so. So much for 1350 being the "safe" number



3. It will not cooldown to a safe temp before shutting it off. I let it sit and idle for 3-4 minutes when I got to work. It dropped from 1100 as I pulled off the highway to 700 once I parked. Would not drop below 700 after idling, I finally just shut it off.



2,100 miles on the truck if anyone is curious.

 

[WAlford]

Wait until you are towing and the thing hits 1500 to 1600 degrees, Dosen't make me feel warm and fuzzy when that happens. My truck regens every 80 miles or so too. So on trips is see those temp quite often. One dealer told me the truck was designed to run 2500 degrees. I told him he was full of it. The dealer I trust said it sounds too hot but we are going to have trust that the engineers did thier jobs right. I'm thinking the manifold is the only thing see that kind of temp due to the exhaust stroke pilot injection and the internals are not getting that hot. The water temp does not move at all when the egt's are that hot. Don't really know though?

 

[Powder Extreme]

This is the first Regen I've seen in the 5-600 miles since I installed the guage. I do tow pretty often, just haven't seen a regen while towing yet. Typically all of my trips are at least 35 miles long mostly highway driving 80-85mph. So if you're seeing every 80miles vs. my 500+ miles, at least we know the regen cycles are "adaptive" (depending on if you have alot of intown driving)

I really can't see how they are designed to take 2500 degrees, that seems pretty extreme. Dunno about cylinder temps, the fuel is still being injected into the cylinder, but at a different time, not sure if that would heat the pistons up as much or not. (I know the pistons were generally the weak link when it came to getting too hot)

 

[Texas Ted]

FOR WHAT IT'S WORTH,

I just finished up the first 1000 mile on my truck. I took delivery in Carson City Nv. and drove on down to Palmdale Ca. Mountains and desert driving, no load and no regen process occurred that I could determine. Pyrometer mtd pre turbo. No spikes over 1100 deg. It always cooled rapidly if I touched the brakes or significantly decelerated. Since then I've driven most of my miles while towing 14k. In the first 1000 miles there have been no regen cycles at all and I've been watching the Pyro steadily.

Ted

 

[KEpperly]

What kinda of fuel mileage are you getting WAlford with all these regen cycles happening all the time. My truck has 1,500 miles on it and i think its stuck in regen mode as it has not pulled out of the 12 mpg range in the past 300 miles unloaded driving is my majority. I used to get 15-16mpg prior to this.

 

[Vaughn MacKenzie]

A few observations on a regen cycle:

1. It DOES happen during in town driving. This morning I drove for 5 miles of highway followed by 10 minutes of in town, ending with 25 miles of highway.
On the highway the regen started, it was running mostly 12-1400 degrees (thermocouple mounted pre turbo between #1 and #2 cylinders) Once I got to town it stayed between 1000 and 1200, normally it would be 5-700. Sitting at a stop light for just over a minute, it didn't drop below 1100 degrees.

I know it supposedly doesn't happen below 30 mph, but my findings totally contradict that. Either the 30mph part is wrong, or my truck is malfunctioning.

2. It gets HOT, really HOT. I drove for 5 miles straight with it never dropping below 1425, at one point I saw as high as 1550 degrees, but that only lasted for 20 seconds or so. So much for 1350 being the "safe" number

That would create some serious underhood heat if it occurred on one of our hot 105-110 degree summer days with the AC running

 

[WAlford]

If I drive in town with lots of stop and go lights average 12. 0 mpg if I do 50% town and 50% highway 14. 5 Runnung enpty on flat highway 18 and pulling my trailer with a 19250 GCVW I get 10 mpg. All hand calculated

 

[NHelmer]

The dealer I trust said it sounds too hot but we are going to have trust that the engineers did thier jobs right.



Yeah, the same one's that said the 47RE was enough for a stock engine, AND a VP44 with a brass sleeve was a good idea AND a LP mounted on the engine with 1/4" banjo fittings was a good idea, AND well you get the idea. #@$%!

 

[courierdog]

Even at 1100 degrees, think about the paint job on the car next to you at the stoplight. I think this could prove to be a problem, even worse what about those plastic cars. There may have been a reason the Germans had the Active Regen Cycle operate only at Hwy speeds. The current agressive active regen cycle does not seem to take into account the vehicle speed. The Passive Regen Cycle was originally thought to be able to accomodate the majority of the driving activity and the Active Regen Cycle was only for the extreme cases such as the C&C applications where the majority of the driving was in the urban environment at speed under 50 MPH, hence the physical construction difference of the DPF. My neighbour, a Heavy Duty Mechanic, with his C&C Service Truck has an ater market Side Stack to keep the Exhaust going up and away from anything in the general area due to the heat during the Active Regen Cycle which does come on in the idle (high idle) condition while the PTO is engaged to run the air compressor and hydraulics involved in his work. So far he has had no mil light or any negative reports. He loves the new truck with the 6. 7 and the Asin 6 speed auto compared to his previous 5. 9 with the manual transmission.

 

[CLamb]

Even at 1100 degrees, think about the paint job on the car next to you at the stoplight. I think this could prove to be a problem, even worse what about those plastic cars. There may have been a reason the Germans had the Active Regen Cycle operate only at Hwy speeds. The current agressive active regen cycle does not seem to take into account the vehicle speed. The Passive Regen Cycle was originally thought to be able to accomodate the majority of the driving activity and the Active Regen Cycle was only for the extreme cases such as the C&C applications where the majority of the driving was in the urban environment at speed under 50 MPH, hence the physical construction difference of the DPF. My neighbour, a Heavy Duty Mechanic, with his C&C Service Truck has an ater market Side Stack to keep the Exhaust going up and away from anything in the general area due to the heat during the Active Regen Cycle which does come on in the idle (high idle) condition while the PTO is engaged to run the air compressor and hydraulics involved in his work. So far he has had no mil light or any negative reports. He loves the new truck with the 6. 7 and the Asin 6 speed auto compared to his previous 5. 9 with the manual transmission.

Gas Motors have EGTs over 1200* all the time. . the car next to you should be OK .

 

[betterthanstock]

Gas Motors have EGTs over 1200* all the time. . the car next to you should be OK .

Here's a graph of airplane engine EGT. Note variation between cylinders. That's what kills the engine, that one hotter cylinder.

 

[courierdog]

It would appear from comments on the TDR forums that once the AU software is installed correctly, the consensus of users report excellent performance and minimal Active Regeneration, with the following readings

EGT - 700-825 Deg @ 60 MPH
Boost - < 1 PSI @ 60 MPH

EGT - 1200-1225 Deg @ 60 MPH During Regen for 4-6 minutes
Boost - < 1 PSI @ 60 MPH during Regen (no change 0-1 PSI)

Freeway driving with cruise control on, flat or level highway.
EGT never exceeds 1225.
Active Regeneration seems to take place every 80 miles or so, depending on the number of starts and stops.

This is as opposed the the reading I currently observe
EGT - 800 - 1000 degrees - on the flat @ 100 KPH/60MPH
EGT - 1200 - 1450 degrees - on the flat @ 100 KPH/60MPH During Regen for hours at a time
EGT - 1200 - 1550 degrees up hill @ 100 KPH/60MPH During Regen for hours at a time
EGT - 1200 - 800 degrees down hill @ 100 KPH/60MPH During Regen for hours at a time

Boost 2 - 2. 5 lbs on the flat @ 100 KPH/60MPH
Boost 5 - 7. 5 lbs on the flat @ 100 KPH/60MPH During Regen for hours at a time
Boost 7. 5 - 17 lbs up hill @ 100 KPH/60MPH During Regen for hours at a time
Boost 5 - 0 lbs down hill @ 100 KPH/60MPH During Regen for hours at a time

 

[Bob4x4]

Au software for 07-07. 5,Ag software for 08



Bob

 

[Wolfy]

It would appear from comments on the TDR forums that once the AU software is installed correctly, the consensus of users report excellent performance and minimal Active Regeneration, ...



Freeway driving with cruise control on, flat or level highway.

EGT never exceeds 1225.



***Active Regeneration seems to take place every 80 miles or so, depending on the number of starts and stops. ***

Hi CD, (Thanks for the recent PM



Regarding the above statement about the 80-mile "Active" frequency:



The regen function, as originally understood (and discussed in the Understanding Regeneratiopn" thread), supposedly suggests that Passive Regeneration should suffice, during "highway" driving, as the EGT's are high enough to accomplish soot burnout.



If the 80-mile Active is in fact needed at continued highway speeds, then the passive regen must be accomplishing only a percentage of what is required to keep the sensors happy,... with the frequent active regen taking up the slack.



Does anyone have comment on this hypothesis?



If all is right with our rig,... should we, or should we not, expect to see frequent active regen when driving hundreds of miles on a trip, at highway speeds, with pit/fuel stops the only interruption? (Every one of these "Active" sessions is burning fuel that does nothing to move us down the road. )



I assume that the continuing series of "flash" developments by D/C are intended, in part, to achieve the minimum EFFECTIVE frequency, and thus preserve what fuel economy is possible with the new DPF system.



I believe these "Flash" notices to the service departments contain a description of what changes the service is intended to accomplish,... but I have not seen any such description of the PURPOSE of the latest "AU" flash posted in this forum.



Can someone supply the membership with this information ( or provide me a link to where it has already been posted)?



My rig has only the "Rev. A" flash (No "B",. . no "AU"), but has not demonstrated the high active frequency/duration described by some posters. (Maybe I should focus a mounted camcorder on the gauge for awhile, and review the tape later to find out if I am simply failing to notice the cycles. )



Thanks!

 

[sag2]

There is nothing in print that explains what the flash corrects, but I think we can all assume with great confidence that it is fine tuning the regen process to take into account some of the varied drive cycles they may not have anticipated. I guess as long as the check engine light stays off it really does not matter what the flash does. If you knew what it did anyway, it still makes no difference. The idea is to keep the CEL off, the fuel economy as high as possible and the emissions within the limits set by the feds.
Also as long as the exhaust temp stays high enough to burn off the particulates, you should not necessarily see any regen occurring. It is still based on an algorithm with some input from the various sensors to fine tune the process, so it still may do things you might not expect it to. I can't think of anyone that had trouble that was not confirmed by the CEL being on. And I have not seen a post from anyone that has plugged DPF after the first of the flashes were released. The worst is certainly behind us, and most all that are going to have serious trouble have already had it.

 

[Wolfy]

If you knew what it did anyway, it still makes no difference.

"All men, by virtue, desire to know. " (Aristotle 384-322 BC)



When someone says "You do not need to know,... it is enough that I know. Trust me. " ...



Don't.

 

[courierdog]

I am totally convinced that the only important issue is the CEL remaining off.

here is a sample of my current EGT/Boost readings

EGT - 800 - 1000 degrees - on the flat @ 100 KPH/60MPH

EGT - 1200 - 1450 degrees - on the flat @ 100 KPH/60MPH During Regen for hours at a time

EGT - 1200 - 1550 degrees up hill @ 100 KPH/60MPH During Regen for hours at a time

EGT - 1200 - 800 degrees down hill @ 100 KPH/60MPH During Regen for hours at a time



Boost 2 - 2. 5 lbs on the flat @ 100 KPH/60MPH

Boost 5 - 7. 5 lbs on the flat @ 100 KPH/60MPH During Regen for hours at a time

Boost 7. 5 - 17 lbs up hill @ 100 KPH/60MPH During Regen for hours at a time

Boost 5 - 0 lbs down hill @ 100 KPH/60MPH During Regen for hours at a time

DTC Codes are as follows:

P0402 - EGR Flow Excessive Detected

P042E - Catalyst Efficiency - LOW

P0489 - Exhaust Gas Recirculation Ctrl Circ Low

P245A - EGR Cooler Bypass Control Circuit - Open

P2262 - Turbo Boost Press Not Detected-Mechanical

P2453 - Diesel Particulate Filter Differential Pressure Sensor Circuit Range/Performance

So I am talking of trips whch last over 1000 Km at sustained speeds with the above readings so please don't tell me this is considered normal

 

[Wolfy]

EGT - 1200 - 1450 degrees - on the flat @ 100 KPH/60MPH During Regen for hours at a time (etc. ).

...



I am talking of trips whch last over 1000 Km at sustained speeds with the above readings so please don't tell me this is considered normal

CD, I am beginning to forget who has posted what.



Have you had the "au" flash?



What sort of fuel mileage are you getting with these "hours at a time" regen sessions?



Thanks,

 

[courierdog]

As of the previous Post I did not have the AU Reflash.
Yesterday, Oct 02, 2007 the AU Reflash was performed as well as the replacement of the EGR Valve.
Today on a trip lasting a total of 3. 5 hours at speed here are the new readings:
Trip Oct 03, 2007 - 159 Km each direction
EGT - 960 degrees - on the flat @ 100 KPH/60MPH
EGT - 1260 - 1320 degrees - on the flat @ 100 KPH/60MPH One occurance of Regen for 18 Minutes.

Boost 5. 0 lbs on the flat @ 100 KPH/60MPH
Boost 5. 0 lbs on the flat @ 100 KPH/60MPH During Regen for hours at a time

The Exhaust Break appears to be a little more aggressive, which is a good thing.

Fuel Efficiency is a tiny bit improved

So it would appear some progress has been achieved however the EGT is still running 260 degrees hotter than previous and 260 degrees higher than the reported average on the TDR.
This is still of concern to me as this speaks to a shortened life of the Pistons, Valves and Turbo
I am surprised with the increased in running boost pressure.