Confusion between EGR systems: Cummins 6.7 and DT644E

[baipin]

Trying to get something straightened out here, between...

• A: Confirm which emissions controls are on 2004-2007 Cummins 6.7 and DT644E.

• B: What the reliability of 2004, 2005, 2006 and 2007 engines is like - which to my understanding, have EGR but no DEF/DPF systems.

Not sure if all I'm assuming is true, but here goes...

It's my understanding that EGR systems are less reliable than completely mechanical or electronic engines that existed pre-2004. EGR was implemented by all manufacturers at 2004 until present. By 2007, in addition to EGR, DPF/DEF was used. It is with this latter batch of emissions controls, which use DEF/DPF, that the majority of problems with modern buses arise. EGR is less reliable than an engine with no emissions controls, but it is not particularly bad, much better than where DEF/DPF systems are used too. At the very least, EGR problems are less costly to fix than DPF/DEF.

It's also to my understanding that some IC CE300 buses from 2005 to 2007 included the DT466E which is not the same as a the Maxxforce DT or Maxxforce 7 that were introduced from 2008 until 2016. It's just a classic, old-school-ish DT466E, but with EGR added on. Therefore, it is a relatively reliable choice.

As for the Thomas C2, which was built starting in 2004; the Cummins 6.7 came with only EGR for 2004, 2005, 2006, and the first 6 months of 2007. In that regard, it is equivalent to the aforementioned DT466E in terms of what emissions controls it has.

Therefore, all other things being equal; minimal rust, 2000-series Allison transmissions, etc. Which of these two buses would be a better choice? If any? I've more or less narrowed it down to these two because we have a ridiculous number of IC CE buses around here - it's all anyone ever uses it seems. Plenty of Thomas C2's. Most of the older pre-2004 buses are damn difficult to find, and already rusted out. So, even if I went with the most ideal setup for a C2 or CE, would I still be screwing myself? Should I wait for that rust-free FS65 or 90's International or whatever? Would the difference in terms of reliability be huge?

These are some of the sources I used to come to all the conclusions above - some thoughts on all this would be GREATLY appreciated!

https://cptdb.ca/wiki/index.php/Thom...Saf-T-Liner_C2


https://cptdb.ca/wiki/index.php/IC_Bus_CE_Series



https://www.skoolie.net/forums/f9/ic...tml#post345673


https://www.skoolie.net/forums/f13/s...105-30091.html

https://www.youtube.com/watch?v=DJhqKCr7Qek

(Note the blue-painted engine; I'm pretty sure only DT466(E) were like this, no Maxxforce)?


6.7L Cummins Emissions System Explained


https://en.wikipedia.org/wiki/Navistar_DT_engine

[cadillackid]

I’m confused!
Ha I thought the 6.7 came out in 2007, was it used in freight liner prior?

Most manufacturers tried to keep their DPF clean without DEF. so DEF came along in most in 2010 or after.

On the DT side
DT466 mechanical - no emission no computer ended in 97/98 in busses
DT466E first Gen. no emissions was 94.5 - 2003
DT466E second Gen (EGR) 2004 -2007

Maxxforce DT (466E base) Gen 1 was 2007-2009 (EGR, DPF, VGT(variable single turbo)

MaxxForce DT (466E base but very modified) 2nd Gen was 2010 - end. (EGR,DPF, DEF, compound turbo , common rail) - these were the most problematic generation of “466’. Also the most powerful.

Someone else can chime in for the Cummins side of things.

[baipin]

Originally Posted by cadillackid

I’m confused!
Ha I thought the 6.7 came out in 2007, was it used in freight liner prior?

It could of - I haven't seen anything about the 6.7 earlier than 2007, but allegedly they were used in 2004 in the Freightliner... that website I linked is the only evidence I've found, but they also have never gotten anything wrong before, from what I've seen.

Most manufacturers tried to keep their DPF clean without DEF. so DEF came along in most in 2010 or after.

On the DT side
DT466 mechanical - no emission no computer ended in 97/98 in buses
DT466E first Gen. no emissions was 94.5 - 2003
DT466E second Gen (EGR) 2004 -2007

So would you say the DT466E is still a solid, reliable choice? If not, can it be bulletproofed in known ways? Would it be worth my while to seek out a 466E first gen or a 466 mechanical instead? Like I said, going that old, I keep running into severe rust issues.


Thanks for the input and confirmation!

[cadillackid]

I have different opinions because for me if I break it I’ll just fix it..
the the EGR 466e there are updated oil cooler and EGR cooler parts which helped with a lot of the issues..

There were some coolant cavitation issues in those engines that doing a new timing cover set solves. If they occur.. these engines were extremely sensitive to coolant maintenance . Use the right coolant and additive (if required) and the issue didn’t occur.. I have seen these engines go 300k more than once before major work.. many much farther.. but not maintaining the coolant and both coolers mentioned above fail as well as the timing cover.. it’s a gamble.. if a bus is inspected in person it’s easy to tell if the navistar recommended coolant is in it .. if it’s green coolant then a test strip tells you if it’s in spec .. of course auctions make that much tougher to do as you are remote with only a picture or 2..

The maxxforce DT Gen 1 is same as 466e egr only it added more complexity.. again proper maintenance and these are solid. But letting DPF stay clogged and trying to regen it clean with the dash buttons was one way people damaged them .. or again poor coolant and oil care..

Thus why many state 03 and older because poor maintenance didn’t cause as many issues plus less complexity.. a lot depends on your skills wheelhouse.. for me personally rebuilding engines swapping gears, trans , etc is no big deal but fixing rust is something I don’t have the best skills or tools for.. I’ve been lucky and found older busses with very little rust issues.. heck my 1978 has less rust than some 2013s I see around here..

If your skill set is much better at metalwork than it is engines and drivetrains / electronics then most surely you look for an older bus with a solid drivetrain and running gear even if it means you need to patch a few holes..

[baipin]

Originally Posted by cadillackid

I have different opinions because for me if I break it I’ll just fix it..
the the EGR 466e there are updated oil cooler and EGR cooler parts which helped with a lot of the issues..

There were some coolant cavitation issues in those engines that doing a new timing cover set solves. If they occur.. these engines were extremely sensitive to coolant maintenance . Use the right coolant and additive (if required) and the issue didn’t occur.. I have seen these engines go 300k more than once before major work.. many much farther.. but not maintaining the coolant and both coolers mentioned above fail as well as the timing cover.. it’s a gamble.. if a bus is inspected in person it’s easy to tell if the navistar recommended coolant is in it .. if it’s green coolant then a test strip tells you if it’s in spec .. of course auctions make that much tougher to do as you are remote with only a picture or 2..

The maxxforce DT Gen 1 is same as 466e egr only it added more complexity.. again proper maintenance and these are solid. But letting DPF stay clogged and trying to regen it clean with the dash buttons was one way people damaged them .. or again poor coolant and oil care..

Thus why many state 03 and older because poor maintenance didn’t cause as many issues plus less complexity.. a lot depends on your skills wheelhouse.. for me personally rebuilding engines swapping gears, trans , etc is no big deal but fixing rust is something I don’t have the best skills or tools for.. I’ve been lucky and found older busses with very little rust issues.. heck my 1978 has less rust than some 2013s I see around here..

If your skill set is much better at metalwork than it is engines and drivetrains / electronics then most surely you look for an older bus with a solid drivetrain and running gear even if it means you need to patch a few holes..

Thanks for all that insight!


I am pretty meticulous when it comes to vehicles. Big rigs are completely new to me (though I do have truckers and diesel techs in the family, other side of the country though). Engines are not as much my thing as metal fab is though, but I can work with either. With that said, would you pass on IC CE's completely, a pre-2003 with more rust would be a better deal, you think?

[cadillackid]

I dont pass on IC CE altogether. . each bus has to be looked at individually.. but yeah i'd look for something pre 04.. Cummins, CAT. DT466E, (T444E is excellent just lacks in power)..


some things to think about in pre 04


AT545 transmissions were in production through 2003.. so if you dont want one be sure to make sure the bus is equipped with a different transmission..



DT466E were looked at as pretty solid.. they were however made startimg at 175 HP on up.. the 175s / 195 are pretty weak in a full size bus.. the computers can be turned up some with the right software..



T444E are the venerable uncle to the Powerstroke 7.3, regarded often as the best V8 diesel produced.. that said, theres lots of aftermarket parts support.. however they dont like to move a full size bus around real well.. the V8 diesel isnt as torquey as an inline 6 engine.. while its reliable its not gonna fly.. (I hasve a shorty with one turned up pretty good so that bus moves out however thats with a tweaked out computer and custom transmision.. and a 6 window shorty.. these were the budget engine so often paired with a 545.. but many also came with 2000 series trans too



CAT 3126 - another solid candidate.. not super fast but they have a good reputation for being reliable and the higher horsepower variants do have good power..



Cummins 5.9 - a classic in its own realm.. Tons of aftermarket support, in stock form they are a tad small in a big heavy bus however power-adders exist in many forms for them.. again you see these with AT545s a lot.. but were also offered with the 2000 series and 3060 as well..



Cummins 8.3 - pair this with an MD3060 trans i na rear engine bus and many consider it the Holy grail skoolie drivetrain.. these engines have good reputations overall and have the power and torque to move a full size bus around pretty good.. since many of these were bought in mountain states where the tendency is to use plows and sand for snow removal vs salt so can often find these with little rust.. That said, everyone wants these so the $$ is usually higher..



im sure there are other engines and other experiences.. but thats my main take on the pre 2004 engines (there are mechanical engines even older.. im just focusing on stuff you'd see in that 00-03 range.. I should mention that the 444E was made through 04 with no EGR)

[baipin]

Originally Posted by cadillackid

I dont pass on IC CE altogether. . each bus has to be looked at individually.. but yeah i'd look for something pre 04.. Cummins, CAT. DT466E, (T444E is excellent just lacks in power)..


some things to think about in pre 04


AT545 transmissions were in production through 2003.. so if you dont want one be sure to make sure the bus is equipped with a different transmission..



DT466E were looked at as pretty solid.. they were however made startimg at 175 HP on up.. the 175s / 195 are pretty weak in a full size bus.. the computers can be turned up some with the right software..



T444E are the venerable uncle to the Powerstroke 7.3, regarded often as the best V8 diesel produced.. that said, theres lots of aftermarket parts support.. however they dont like to move a full size bus around real well.. the V8 diesel isnt as torquey as an inline 6 engine.. while its reliable its not gonna fly.. (I hasve a shorty with one turned up pretty good so that bus moves out however thats with a tweaked out computer and custom transmision.. and a 6 window shorty.. these were the budget engine so often paired with a 545.. but many also came with 2000 series trans too



CAT 3126 - another solid candidate.. not super fast but they have a good reputation for being reliable and the higher horsepower variants do have good power..



Cummins 5.9 - a classic in its own realm.. Tons of aftermarket support, in stock form they are a tad small in a big heavy bus however power-adders exist in many forms for them.. again you see these with AT545s a lot.. but were also offered with the 2000 series and 3060 as well..



Cummins 8.3 - pair this with an MD3060 trans i na rear engine bus and many consider it the Holy grail skoolie drivetrain.. these engines have good reputations overall and have the power and torque to move a full size bus around pretty good.. since many of these were bought in mountain states where the tendency is to use plows and sand for snow removal vs salt so can often find these with little rust.. That said, everyone wants these so the $$ is usually higher..



im sure there are other engines and other experiences.. but thats my main take on the pre 2004 engines (there are mechanical engines even older.. im just focusing on stuff you'd see in that 00-03 range.. I should mention that the 444E was made through 04 with no EGR)

Yeah, I'm definitely avoiding the AT545 lol. No way in hell would I go with one.


What do you think about a 1999-2002 GMC B-series with a 3126 CAT and an Allison 2000? That should have parts shared with topkicks of the era, right? I've found a few, and with luck, they should be rust free, given where they're located. Can't really go see in person though since it's a few provinces away.

[CHEESE_WAGON]

DT466E engines are indeed painted blue. MaxxFarce offerings are usually painted black.

[cadillackid]

yeah the GMC are solid runners.. the allison 2000 series came out in mid-late model year 2000.. the shifter will be R-N-D-4-2-1

the topkick and kodiak trucks ran on the same chassis..



the freightliner FS65 (usually thomas body, although bluebirds exist) also could be had with allison 2000s and CAT-3126