ISX 600 questions

[Steve n Jan]

Currently have a DP with a C-13 Cat, considering another Country Coach Magna with a 600 HP Cummins, wondering what you Cummins guys think of this engine as opposed to a Cat.

[Smitty77]

Hi Steve - What is the year of the coach/engine?

Some ISX's had a problem, you may have seen Mr D's recent problems? If not, search on his posts under this Cummins section, and you will find it. And, while I can't recall the name of the poster, another gent over a year ago posted another similar horror story with his ISX. To be clear, this was only a certain year, and as I recall, it was on the BIGGER BLOCK ISX, not the one that is of smaller displacement tuned to the I think the 500HP rating. No nothing about those!

Worth doing due diligence on the engine in this specific coach, to see if it has the same design as Mr D's. If the coach has this engine, I'd either insist on a pre-emptive fix with the newer parts from Cummins. As part of the agreed to price of the coach. I don't know, but suspect it would be several thousands to swap out the parts with the new and improved components. Which is much better then potentially a $25-30K repair if it fails.

Best,
Smitty

[Steve n Jan]

Originally Posted by Smitty77

Hi Steve - What is the year of the coach/engine?

Some ISX's had a problem, you may have seen Mr D's recent problems? If not, search on his posts under this Cummins section, and you will find it. And, while I can't recall the name of the poster, another gent over a year ago posted another similar horror story with his ISX. To be clear, this was only a certain year, and as I recall, it was on the BIGGER BLOCK ISX, not the one that is of smaller displacement tuned to the I think the 500HP rating. No nothing about those!

Worth doing due diligence on the engine in this specific coach, to see if it has the same design as Mr D's. If the coach has this engine, I'd either insist on a pre-emptive fix with the newer parts from Cummins. As part of the agreed to price of the coach. I don't know, but suspect it would be several thousands to swap out the parts with the new and improved components. Which is much better then potentially a $25-30K repair if it fails.

Best,
Smitty

It's a 2007..Thanks for the reply...I hope this year wasn't the bad one.

[RVNewbie55]

According to this quote the affected years were 2007-2010, but only if it was rated at 650 HP


palehorse89
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Same engine different emission levels from 2007-2010 http://cumminsengines.com/uploads/do..._isx15_isx.pdf
The 650 HP motor was made for the "High End" Coach's Cummins Introduces New 650-hp Diesel Engine for Premium Motorhomes - Cummins Engines
Have not seen/heard of any problems with the newer 600hp ISX Bob, hopefully we don't!
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[Duoglide1]

The coach I bought recently is also ISX. I can only find 2 or 3 in MH applications with the problems Mr D experienced and 2 were 650 hp and one that I heard about but couldn't confirm may have been 600. All were 2007 thru 2010. My Monaco has a sticker showing an Oct 2006 delivery date and the engine data plate looks an 05 build. It's also only rated at 525 and I believe I'll leave it there. All maintenance records are with the coach and it's been to Cummins once for pm and computer updates. All other records are from Motorhomes of Texas and show no engine problems, just belts hoses oil etc. good luck. By the way it appears on the HDT forums most of the problems show up north of 400k mileage wise.


2007 Monaco Executive 45' 525 ISX

[FlyingDiver]

Our KGDB is an '08 with ISX 600. Only one engine repair in over 50K miles, and that was a bad EGR valve that was replaced under warranty. Other than that, just annual maintenance at the Spartan factory.

[spuds]

We know of 2 Foretravels, both 2009 IIRC, and one 2010 Country Coach with 600 hp ISX's that experienced dropped valve seats and engine rebuilds.

[RVNewbie55]

Here are a couple links to this problem on this issue:
http://www.irv2.com/forums/f123/isx-...me-238170.html

http://www.irv2.com/forums/f123/upda...me-239649.html

And there are others as well. Per these links it appeared that the problem was only if the engine was rated at 650 HP, but now appears that is not true. Any of the 2007-2010 with the twin cam head are susceptible.

[Mr_D]

Originally Posted by RVNewbie55

Here are a couple links to this problem on this issue:
http://www.irv2.com/forums/f123/isx-...me-238170.html

http://www.irv2.com/forums/f123/upda...me-239649.html

And there are others as well. Per these links it appeared that the problem was only if the engine was rated at 650 HP, but now appears that is not true. Any of the 2007-2010 with the twin cam head are susceptible.

That would be my take on it too!
Cummins is supposed to have new heads and turbo to cure the problem, or at least that's what we were told. Now I see that Cummins is saying that only the turbo needs to be changed ($14,000).
I also know of an '08 Magna (ISX 650) that was purchased in AZ in not running condition. Owners had it towed to a Cummins shop and spent $20,000 getting it going, then 20 miles from Cummins the engine threw a rid through the block. $44,000 more and Cummins refused any coverage even though they had just worked on it.

[RVNewbie55]

Originally Posted by Mr_D

That would be my take on it too!
Cummins is supposed to have new heads and turbo to cure the problem, or at least that's what we were told. Now I see that Cummins is saying that only the turbo needs to be changed ($14,000).
I also know of an '08 Magna (ISX 650) that was purchased in AZ in not running condition. Owners had it towed to a Cummins shop and spent $20,000 getting it going, then 20 miles from Cummins the engine threw a rid through the block. $44,000 more and Cummins refused any coverage even though they had just worked on it.

If Cummins is saying only the turbo needs replacement, I wonder if they will send out a notice alerting owners of this. I would find it difficult to believe that they would go so far as to say this could prevent a broken valve due to the heat issue in the future Just sayin...if HP produces heat, and we now know that the 600 HP's are having this problem, then would a replacement turbo dial back the HP & or torque below 600 & 1950?

[Duoglide1]

Mine was built in 05, delivered in 06 and it's rated at 525. It's supposed to be able to be updated by Cummins with no hardware change, only computer updates. It does have the EGR but not the DPF or regen features. I can only hope this engine is not subject to the same fate.


2007 Monaco Executive 45' 525 ISX

[RVNewbie55]

I did a search but cannot find it, but Mr. D gave the model # of the engine. Unfortunately mine is one of that model. I believe that is the only model affected as it is the only one with the twin overhead cam, and IIRC the head cannot be interchanged with the single OH Cam version that was built both before and then (after all these problems popped up) after this model. So if MR. D reads this and can remember the model maybe he will chime in here, so anyone with this model can know ahead what to possibly expect.
Bob

[Mr_D]

I'll have to check. right now I'm at work and on their computer but I'll get my laptop out and get it.

OK, found it: ISX CM871 this is the so called 2007 EPA model with the DPF.

The Wiki on it is: https://en.wikipedia.org/wiki/Cummins_ISX

What's kind of strange is that Cummins admits it's a design error and not a batch of bad valves. In our case the new head and turbo are supposed to cure it but I'm kind of leery of the whole thing. Do I dare even use full power or will a valve brake again? Since the rebuild we have a 1 yr/100,000 mile warranty which is really nothing as we'll never get 5,000 miles in a year since the wife has liver cancer and we won't be traveling much for a while if at all.

[Pro55]

Have talked to many people who have had a problem with the cummins isx 650 or know of someone with a problem...word has to get out ...since cummins knows of this problem and has not recalled them ..it seems to be a combo of the turbo and the double cam head... I just had #6 valve break up in three pieces ...looks like high heat tempering problem...am having a new recon motor put in ...final bill will be over$50,000.00 and cummins so far has said it is not under warrantee since is a 2009 monaco with only15000 miles..anyone else having a problem with cummins please let everyone know!!!!....the more the word gets out maybe cummins will listen..thanks