Are all ISX engines bad?

[loranimal]

I have been looking for a new-used coach, 2005-2010. Most have an ISX, 525, 600 or 650. Does one version have more issues then another? Is one year better then others? Should I stay away from all of them?



Thanks


Carl

[Unplanned Tourist]

There are thousands and thousands of them out there in heavy trucks, many going over 1,000,000 miles. The thing with RV's using the ISX is that they are turned up too high, and maintenance is questionable in some cases.
Running at 525 hp, they should outlast the coach easily. As they increase in power, the stresses go up, and dependability goes down, as in any motor.
Happy Glamping.

[Ljwt330]

If you haven't already, read this thread http://www.irv2.com/forums/f123/cumm...-a-401436.html


From what I've gathered, the 650 ISX in an RV has the most issues, followed by the 600 ISX, and the 500 being a solid engine. A lot has to do with the emissions in the later engines and their particular use in RV's. Not simple answer to your question, but there is a lot out there about issues and they tend to be specific to RV usage, not trucks. Costly repairs and not covered by Cummins.

[1doodadd]

Don't walk away, RUN!

[loranimal]

Originally Posted by 1doodadd

Don't walk away, RUN!

Is this from first hand knowledge? What size/year engine did you have?


Thanks


Carl

[Mr_D]

Cummans has found that the EGR is dumping acid laced exhaust back on the #6 intake valve. When the engine sits the acid eats the valve away and it breaks. They call it "chordal valve malfunction". The 650 and to a lesser extent the 600 are especially prone to it. In class 8 trucks it's not as much of a problem as they don't sit for long periods.
My 650 has done it twice, once at 19,000 miles under warranty and again at 45,000 with no warranty for $33,000+ in repairs and I'm getting indications that it's about to do it again at 51,500 miles.

[Unplanned Tourist]

Originally Posted by Mr_D

Cummans has found that the EGR is dumping acid laced exhaust back on the #6 intake valve. When the engine sits the acid eats the valve away and it breaks. They call it "chordal valve malfunction". The 650 and to a lesser extent the 600 are especially prone to it. In class 8 trucks it's not as much of a problem as they don't sit for long periods.
My 650 has done it twice, once at 19,000 miles under warranty and again at 45,000 with no warranty for $33,000+ in repairs and I'm getting indications that it's about to do it again at 51,500 miles.

I have never been a fan of EGR systems on deisel engines. Maybe it is time for an delete kit.
Slightly frowned upon by some, but they are out there.
Happy Glamping.

[Electra 225]

Originally Posted by Mr_D

Cummans has found that the EGR is dumping acid laced exhaust back on the #6 intake valve. When the engine sits the acid eats the valve away and it breaks. They call it "chordal valve malfunction". The 650 and to a lesser extent the 600 are especially prone to it. In class 8 trucks it's not as much of a problem as they don't sit for long periods.
My 650 has done it twice, once at 19,000 miles under warranty and again at 45,000 with no warranty for $33,000+ in repairs and I'm getting indications that it's about to do it again at 51,500 miles.

Mr. D, what indications specifically? Is it sounds, or lack of power or?

[Electra 225]

I have been thinking of moving up one day. Most coaches I have had my eye on have the 600. Has anyone heard how much this has happened with this engine?
Also, what about the 605hp engine?

[Electra 225]

Oops, sorry, I just found your new thread Mr. D. I just read the answer to the question I asked you.

I believe I found the answer to my second question as well in your 1st thread on this subject. I guess the answer is yes, the problem still exists on the brand new 600 and 605hp engines. I'd still like to know how often this problem has occurred post 2015.

[Mr_D]

Originally Posted by Electra 225

I have been thinking of moving up one day. Most coaches I have had my eye on have the 600. Has anyone heard how much this has happened with this engine?
Also, what about the 605hp engine?

The newer SOHC engines do not seem to have a problem. It's the older CM871 DOHC ones that fail.
Cummins has released a new head, valves, valve inserts, pistons and liners with carbon scrapers. Cost to proactively rebuild the engine could be in the $20-25,000 range. After the failure $30-40,000.
I'll know more when I do some checking tomorrow with Cummins.

[Electra 225]

Thanks Dean, I found your description above in your other thread just a bit ago. I was thinking the problem still exists after 08navigator's post #266 in your original thread.
I look forward to hearing what Cummins tells you.

[spuds]

Originally Posted by Ljwt330

If you haven't already, read this thread http://www.irv2.com/forums/f123/cumm...-a-401436.html


From what I've gathered, the 650 ISX in an RV has the most issues, followed by the 600 ISX, and the 500 being a solid engine.

There are reports of the 500 having the same issue as well http://www.irv2.com/forums/f109/stil...ml#post4090850

[Electra 225]

Just read that. How did that come out? She never did say.......