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+--- Thread: New ISX motor ? (/showthread.php?tid=4470)
RE: New ISX motor ? - Rawze - 04-27-2019
(04-27-2019 )rockinrandall Wrote: bought new 2019 t800 x15 in nov 2018 have 50 thousand miles on it now run same route every day getting 6.2 pulling fancy gap in va at 82 thousand 565hp 2050 torque
I hope like hell that thing has 3.79's or 3.90's in it for that operation + your keeping the RPM's up at 1600 when pulling. Otherwise, I see you re-building that thing in 300-400k miles or so (far less if it has a bad/poorly written de-mandate in it).
cummins should have never put 2050 torque in the ISX the way they did, especially the newer ones with high compression like the 2350 or X15.. They only put that torque in them from the 1100-1300 RPM range where it completely tortures/beats the liners out of them.
If I owned it and needed to have high HP,.. I would lower the torque and raise the HP to something more usable in the higher RPM ranges where it needs to be.
RE: New ISX motor ? - Magard - 04-27-2019
If your in Cali then 2250 2350 makes no difference. Your gonna have to fix it anyway.
RE: New ISX motor ? - Camstyn - 04-28-2019
(04-27-2019 )rockinrandall Wrote: would like to hear what others with this motor are doing
Just put a new 2020 389 on the road with X15 565/2050 turned down to 485/1850. First few fill ups have been 5.9, 5.3, 6.2 and 5.7. Hoping it continues to improve as it warms up and we get better diesel. The truck it replaced was a 579 with 500/1850 Paccar MX and it was using around the same in March. Seems to have about the same pulling power on this setting.
RE: New ISX motor ? - Camstyn - 05-08-2019
A few questions, this is the only Cummins I’ve owned besides the 870.
Is 32psi oil pressure normal at operating temp, 1500rpm?
Is it normal for the turbo to continue to make close to 10lbs boost for a while after you’ve let off the throttle and started coasting? Feels like it’s putting resistance on the engine. Does not do it all the time.
Jake is weak, like weaker than my Paccar MX. You can hear/feel the difference between the 3 jake settings so 3rd stage is definitely activating. What could cause this in a brand new truck? It also shakes the truck (not violently) when it gets down to 1300rpm and under.
RE: New ISX motor ? - Rawze - 05-08-2019
(05-08-2019 )Camstyn Wrote: A few questions, this is the only Cummins I’ve owned besides the 870.
Is 32psi oil pressure normal at operating temp, 1500rpm?
Is it normal for the turbo to continue to make close to 10lbs boost for a while after you’ve let off the throttle and started coasting? Feels like it’s putting resistance on the engine. Does not do it all the time.
Jake is weak, like weaker than my Paccar MX. You can hear/feel the difference between the 3 jake settings so 3rd stage is definitely activating. What could cause this in a brand new truck? It also shakes the truck (not violently) when it gets down to 1300rpm and under.
32 psi oil pressure sounds a bit low unless your oil temp is upwards of 230+ degF.
other than that, assuming it is not a de-mandated truck and still has factory programming,.. everything else you describe sounds normal. - How else is the engine supposed to keep the SCR can at 600+ degrees, or warm it up rapidly when it cools off too much?. The factory programming places a load on the engine (depending on what engine run mode it has chosen) with the turbo by choking the exhaust whenever it sees the exhaust cans getting cooled off too much.
RE: New ISX motor ? - Camstyn - 05-08-2019
Makes sense about the turbo/exhaust noise, hadn’t thought of that. It was probably just a lot less noticeable on the Paccar because of the under-hood air cleaner.
Oil temp seems to hover around 225. Still a little concerned about the jake performance, as from everything I’ve heard it’s supposed to be very impressive and it’s not, at all. Works good enough for the light duty work we’re doing but it doesn’t seem right.
RE: New ISX motor ? - schISM - 05-09-2019
(05-08-2019 )Camstyn Wrote: Still a little concerned about the jake performance, as from everything I’ve heard it’s supposed to be very impressive and it’s not, at all. Works good enough for the light duty work we’re doing but it doesn’t seem right.
Im not sure about the X-15 but other models use a different cpl for 500hp and above. If you turned it down with a factory tune chances are it’s wrong and affecting the Jake and mileages adversely.
RE: New ISX motor ? - Camstyn - 05-09-2019
Mileage seems decent, I’m getting 6.5mpg driving it myself, and that’s with winter XDS2 tires. I’ll have to check with the deslership about the jake.
Rawze, do you still recommend coasting out of gear with a mandated truck? Your comment about the SCR can temp has me curious. There are places where I can coast in neutral for 10+ miles at a time.
RE: New ISX motor ? - Rawze - 05-09-2019
(05-09-2019 )Camstyn Wrote: ...
Rawze, do you still recommend coasting out of gear with a mandated truck? Your comment about the SCR can temp has me curious. There are places where I can coast in neutral for 10+ miles at a time.
not so much,... It cancels the regen and other processes when you coast very much.