Opinions on ISX

[RunningHard]

I am looking at a 2016 Renegade Super C on a Freightliner Cascadia, powered by a ISX 525 HP, 1850 lb tq engine. The transmission is a 13 speed ultra shift. I currently have a 5.9 Cummins in my 07 Winnebago Journey, and it has been a problem free coach. The coach I am looking at has 19k on the clock. I have friends that have Detroit Diesels, but know no one with this particular set up. I have read here about issues on the higher HP ISX, but not much on the 525....any and all comments are more than welcome. Thanks to all for the assistance.

[Kennzz05]

Its as troublesome/trouble free as any modern engine that ingests its own exhaust can be. Mechanically that's the isx cm 2350 most of the bugs are worked out on that design. Your issues will likely all be sensor and emission related. Grab the ESN off the engine tag located on drivers side front of valve cover...go to quickserv.com register and see if there's any recalls due. Or join Cummins isx problem solvers on Facebook and have someone look it up for you. The problems you're referring to are the head and liner issues on the 650hp pushers

[Kennzz05]

https://quickserve.cummins.com/info/index.html

[Mr_D]

I have yet to see a liner problem reported in the CM871 ISX 650's used in motorhomes.

[Mark D]

Originally Posted by RunningHard

I am looking at a 2016 Renegade Super C on a Freightliner Cascadia, powered by a ISX 525 HP, 1850 lb tq engine. The transmission is a 13 speed ultra shift. I currently have a 5.9 Cummins in my 07 Winnebago Journey, and it has been a problem free coach. The coach I am looking at has 19k on the clock. I have friends that have Detroit Diesels, but know no one with this particular set up. I have read here about issues on the higher HP ISX, but not much on the 525....any and all comments are more than welcome. Thanks to all for the assistance.

I have a 650 ISX that had the valve issue. Through the process I found that by 2015 ish all the issues were worked out. It mostly came down to valve material. The head casting changed a bit.

I wouldn't have am issue buying another Class A with an ISX with an engine build after May 2015.

[QMThomas]

I have a 2004 525 ISX with 85k on it and it has been trouble free except a starter and a water pump. I have an Allison 4000 trans although the ultrashift would be nice! The 4000 could use more gears.

[Mr_D]

Originally Posted by QMThomas

I have a 2004 525 ISX with 85k on it and it has been trouble free except a starter and a water pump. I have an Allison 4000 trans although the ultrashift would be nice! The 4000 could use more gears.

Agreed. The first 4 are OK but the overdrives have too much jump between them. Once speed drops enough to drop into 4th mine will climb anything but on a steeper grade I can't pull 5th. A 10 or 12 speed would be great!

[Mr_D]

Originally Posted by Mark D

I have a 650 ISX that had the valve issue. Through the process I found that by 2015 ish all the issues were worked out. It mostly came down to valve material. The head casting changed a bit.

I wouldn't have am issue buying another Class A with an ISX with an engine build after May 2015.

That's my problem! Mine was rebuilt in May 2015. The bill shows the first iteration of new head, but Cummins was slipstreaming the valves so using up the old stock first. As a result they can't tell me what valves are in that head. So I'm having a new head installed later this month. Then maybe I can enjoy my rig!!!

[hypoxia]

OP is looking at a forward mounted ISX in a super C which should be the same as the OTR trucks. Don't most problems come with the backwards mounted engines?

[RunningHard]

Originally Posted by hypoxia

OP is looking at a forward mounted ISX in a super C which should be the same as the OTR trucks. Don't most problems come with the backwards mounted engines?

Yes, I was just going to mention this. The rig was ordered in May of 15', I have seen the order sheet and it shows a 16 Freightliner Cascadia 525 hp Cummins, ultrashift on the build sheet. Thanks everyone for the comments they are appreciated.....

[spuds]

Get the ESN and check it against this (intake valve issues on 2014-2018 engines)

http://www.engineprofessional.com/TB/TB040318-2.pdf

[MCW427]

I’m looking to purchase a coach the same as yours. I will be pulling a 28’ stacker with 2 cars and a Harley. It will weigh in at around 21,000 lbs. I will be using a trailer toad so Very minimal weight on the MH. The coach I am looking to purchase went into a custom frame shop and had the entire rear end beefed up and a 20,000 lb hitch installed. My question is, how well do you think my coach will pull with this 600 hp isx. Anything you could share with me will be appreciated. Thank you

[hypoxia]

Originally Posted by MCW427

I’m looking to purchase a coach the same as yours. I will be pulling a 28’ stacker with 2 cars and a Harley. It will weigh in at around 21,000 lbs. I will be using a trailer toad so Very minimal weight on the MH. The coach I am looking to purchase went into a custom frame shop and had the entire rear end beefed up and a 20,000 lb hitch installed. My question is, how well do you think my coach will pull with this 600 hp isx. Anything you could share with me will be appreciated. Thank you

You will be near 70,000 pounds and just a little more HP than a OTR truck. I think you will pull the big hills marginally better than they do. I'm pulling 7,000 lbs., 54,000 combined and am at 45 MPH on the long 6% pulls. I have no cooling problems and just let the Allison do its thing. You can be pro-active with manual shifting and do better speed wise.

[Mark D]

Originally Posted by MCW427

I’m looking to purchase a coach the same as yours. I will be pulling a 28’ stacker with 2 cars and a Harley. It will weigh in at around 21,000 lbs. I will be using a trailer toad so Very minimal weight on the MH. The coach I am looking to purchase went into a custom frame shop and had the entire rear end beefed up and a 20,000 lb hitch installed. My question is, how well do you think my coach will pull with this 600 hp isx. Anything you could share with me will be appreciated. Thank you

I weigh in at 55,000 pounds and have zero issues with power. Commercial trucks run at 80,000 pounds all day long and few have a 600 plus hp engine.

The torque is what you want, no mh with an allison 4000 will have more than 1,950. You will feel the weight at starting from zero and if it's a long grade. Set the CC to 65 or lower and let the engine and transmission do the work.

What year engine will you have? Changing the head isnt a huge issue just costs a few bucks.