05' build ISX 15, in 06' model KW.

[Chadster]

Hey y'all,
I'm new to the forum and to Cummins, been running pre-egr Cats most of my 30 year career. I got my 06' T-600 this past Oct. I don't know what an 870, 871, etc is and don't know what my serial # is. It's not on top, side front or anywhere but I'll see if the KW parts dept can look it up. What's got me concerned is the cold start ups. Fires right up but stumbles, runs rough, in constant and shakey. It sounds like it wants to cut off but doesn't. So I give it a minute, feather the throttle lightly and finally set the cruise to 1000 rpm where it levels out a little but not completely. During this time it's putting out blue smoke but not heavy. After the temp gauge moves up to 100°F or so it gets better and once it's up to 120-140°F and ready to roll it's perfectly fine and runs like a beast and the smoke clears up. I was told that it's got a tune on it but that tells me nothing because there are so many different kinds of tunes out there that it's hard to say what this particular tune was trying to accomplish or if the tuner knew what they were doing. I also have read a lot that ISX'S like the higher rpm and do better both efficiently and powerfully at higher rpm, between 1600-1900. Which doesn't feel right to me but doesn't mean that it's not. As I've spent most of my career running CATS at around 1500rpm and getting close to and sometimes over 8 mpg running them that way. I have a 13-spd with 3.70 rears and 67mph it tachs out at a hair under 1600 rpm. So any advice or suggestions about this motor would be greatly appreciated. Stay safe out there drivers and thanks in advance for your suggestions.

[hhow55]

For starter's you need to setup an account on quickserve.cummins.com. Next, Get yourself cummins insite, which can be purchased on ebay. Third, Get a injector leak test kit.

[hhow55]

https://amzn.to/3U86I65

[Rawze]

(11-27-2022 )Chadster Wrote:  Hey y'all,
I'm new to the forum and to Cummins, been running pre-egr Cats most of my 30 year career. I got my 06' T-600 this past Oct. I don't know what an 870, 871, etc is and don't know what my serial # is. It's not on top, side front or anywhere but I'll see if the KW parts dept can look it up. What's got me concerned is the cold start ups. Fires right up but stumbles, runs rough, in constant and shakey. It sounds like it wants to cut off but doesn't. So I give it a minute, feather the throttle lightly and finally set the cruise to 1000 rpm where it levels out a little but not completely. During this time it's putting out blue smoke but not heavy. After the temp gauge moves up to 100°F or so it gets better and once it's up to 120-140°F and ready to roll it's perfectly fine and runs like a beast and the smoke clears up. I was told that it's got a tune on it but that tells me nothing because there are so many different kinds of tunes out there that it's hard to say what this particular tune was trying to accomplish or if the tuner knew what they were doing. I also have read a lot that ISX'S like the higher rpm and do better both efficiently and powerfully at higher rpm, between 1600-1900. Which doesn't feel right to me but doesn't mean that it's not. As I've spent most of my career running CATS at around 1500rpm and getting close to and sometimes over 8 mpg running them that way. I have a 13-spd with 3.70 rears and 67mph it tachs out at a hair under 1600 rpm. So any advice or suggestions about this motor would be greatly appreciated. Stay safe out there drivers and thanks in advance for your suggestions.

red ISX's are very different from that old yellow engine you had. It has shorter connecting rods and a lot of lateral thrust (side-wall thrust) in the cylinders at lower rpm's.. so yeah.. they will last longer driving them above 1500 rpm than they will by lugging the crap out of one below this.. especially when trying to climb a hill, etc. People tend to lug them to death at lower RPM's and then complain about it dropping liners / blowing head gasket prematurely.

Higher rpm ranges also will NOT make it suck any more fuel once the truck has even a light load on it. Making more power with the engine does. Its called the law of thermodynamics. More, or improper power being made = more fuel used. My own truck gets driven hours on end at 1500+ and 80,000 lbs gross, totally loaded down and I bust 8+ mpg out of it on the low end, and 9.5+ on the high end.
ref: http://rawze.com/forums/showthread.php?t...6#pid64866

They also have a much higher compression ratio in them.. so depending on what model ISX you have.. it is very easy to damage the engine with too much turbo boost.

If it is an '05 or '06 engine, it is likely a CM870 (egr-only engine with an air-operated turbo). If that is what it is then any more than about 37-38 psi boost under max engine loads and that engine will get destroyed.

Also... ASSUME THE PROGRAM IS BAD!!!... The trucking industry is absolutely plagued with bad delete programs.. especially for the ISX's out there.. and the bigger the name shop, and more popular they are.. the worse the programming absolutely is. Your chances of having a bad/harmful program are above 90% for that engine. This can also cause the engine to run funky when cold, etc.. depends on how bad the program really is.
ref: http://rawze.com/forums/showthread.php?t...5#pid13255

Copy the program out of the ecm and e-mail it to me for a proper review of what someone has done in there. That is one of your very next move if you give a damn about that engine at all.

Also.. an ISX will run rough for many reasons including the head itself being worn out, or a re-worked head that someone has slapped on there during an inframe.. which is a big no-no.

Start by adjusting the overhead valves properly and then following this with an injector leak test.
ref: http://rawze.com/forums/showthread.php?t...8#pid67948

By the way.. If your engine is EGR only and has an air actuated turbocharger.. then it is a CM870 engine. If it has(had) a DPF filter and an electronic turbo controller on it then it is a CM871.

You can also look up your engine ser# on quickserv.com by entering your vin# on a search. If you post your vin# then I am sure someone on here can do this for ya as well.

-0== Also.. the advantage of owning a red engine is the fact that you can do everything yourself and you have 100% of all resources that all the repair shops and OEM dealer$shits have too. That is its only advantage to owning one... you can keep it out of the expensive repair shops completely if your zealous enough to work on it.. and it is a great money-making engine that can be molded into what someone needs within reason. -= No other brand and make of truck engine, can you get all the programming, engineering, drawings, procedures, all software, etc. for. so easily.


They are extremely reliable as long as you do regular recommended maintenance and tune-up work to them PROPERLY AND THOROUGHLY .. but if you ignore it for even a little bit.. it will be like the red headed step child everyone hates. -= That is what owning a red engine is like.. so either you learn to take care of it very well YOURSLEF to some medium degree and not abuse or torture it.. and you will not want to own anything else ever again.

Or you can be like the bulk of the trucking fools out there, ignore it until the check engine lights plague it, lug it to an agonizing death because some idiot mega-fleece put a 1500rpm limiter in it below top gear, and hate it to death because you cannot keep it out of a shop. Take your pick on how you want to run your trucking business because there is no in-between with the red engines.