ISX 500 or ISX 600 what engine to look for

[Piros1]

Well I am in the market for a newer coach, I presently own a 2005 CC with a C13 Cat 525HP. Looking for a coach with a few things mine does not have and cannot add or at least I am told they cannot be added. So my question is what engine to look for? With all the issues I hear regarding the ISX600 I am leaning toward the ISX500. I do not think I would be happy with the ISL450 after have my 525 Cat. The ISX500 is only 25HP less and about the same torque as I am use to. Since Cummins pretty much owns the RV market these days unless you want a Prevost I am not sure what to look for. I have seen a few post regarding the 600 and I do not think I am willing to take the chance that I will not have the same issue. It would be different if Cummins was willing to step up and take responsibility but I am not ready to shell out $30,000.00 to $50,000.00 for an engine with low miles. It would be a lot different if it had 300,000 plus miles on it. Any good educated info would be great. Not really looking for opinions just facts and experience. Thanks in advance.

[Mark D]

Originally Posted by Piros1

Well I am in the market for a newer coach, I presently own a 2005 CC with a C13 Cat 525HP. Looking for a coach with a few things mine does not have and cannot add or at least I am told they cannot be added. So my question is what engine to look for? With all the issues I hear regarding the ISX600 I am leaning toward the ISX500. I do not think I would be happy with the ISL450 after have my 525 Cat. The ISX500 is only 25HP less and about the same torque as I am use to. Since Cummins pretty much owns the RV market these days unless you want a Prevost I am not sure what to look for. I have seen a few post regarding the 600 and I do not think I am willing to take the chance that I will not have the same issue. It would be different if Cummins was willing to step up and take responsibility but I am not ready to shell out $30,000.00 to $50,000.00 for an engine with low miles. It would be a lot different if it had 300,000 plus miles on it. Any good educated info would be great. Not really looking for opinions just facts and experience. Thanks in advance.

The ISX issue is based on year not HP, it's a valve issue not a HP issue.

I have a failed ISX engine, it had a new head put on it and it runs great. If you find a Coach you like with an ISX that was produced before 2015 then offer 20k less than normal and have the head replaced.

I have the CM871 with 650 HP. I just made the trip back from the south to CT, I weigh in at 55k and was passing people at 65 MPH up long steep hills in PA, NY and CT. There is a reason the larger coaches have the ISX.

[Piros1]

My feelings were similar regarding the offer less but sellers aren’t taking that into consideration. Also one owner of a 2009 CC Magna has done is twice and possibly going for a third time. I think the first two were pretty catastrophic don’t remember for sure. So anyway did you catch yours before the valve dropped? Also I think this seems to be happening in all years before the 2017 engine.

[Mr_D]

Originally Posted by Piros1

My feelings were similar regarding the offer less but sellers aren’t taking that into consideration. Also one owner of a 2009 CC Magna has done is twice and possibly going for a third time. I think the first two were pretty catastrophic don’t remember for sure. So anyway did you catch yours before the valve dropped? Also I think this seems to be happening in all years before the 2017 engine.

Sounds like you're referring to my CC. Mine is at Cummins right now for it's third rebuild in 51,000 miles. First two the intake valve in #6 broke off. This time it's preemptive since it was rebuilt right as Cummins came out with new parts and they can't tell me if I got them or not.
Cummins shop said one valve was showing damage and liners were rust damaged inside the bore I looked at the liners and it looks more like acid damage. Cummins calls it "chordal malfunction". Acid laden exhaust gasses are recirculated through the engine and erode the #6 intake, then the heating/cooling cycles break the valve. New head casting, new valves and seats are supposed to be the cure. Beginning estimate was $18,000, but due to the liner damage and some other work I'm up to $31,000.
The problem engines are the 2007 EPA CM 871 650 hp models. So far the 600's don't seem to have the same problem. The 2010 and later models also seem to be reliable.

[Piros1]

Originally Posted by Mr_D

Sounds like you're referring to my CC. Mine is at Cummins right now for it's third rebuild in 51,000 miles. First two the intake valve in #6 broke off. This time it's preemptive since it was rebuilt right as Cummins came out with new parts and they can't tell me if I got them or not.
Cummins shop said one valve was showing damage and liners were rust damaged inside the bore I looked at the liners and it looks more like acid damage. Cummins calls it "chordal malfunction". Acid laden exhaust gasses are recirculated through the engine and erode the #6 intake, then the heating/cooling cycles break the valve. New head casting, new valves and seats are supposed to be the cure. Beginning estimate was $18,000, but due to the liner damage and some other work I'm up to $31,000.
The problem engines are the 2007 EPA CM 871 650 hp models. So far the 600's don't seem to have the same problem. The 2010 and later models also seem to be reliable.

Yes sir I was referring to one of your posts I read. Very sorry you are going through this a third time. You must love the coach, I would have sold or traded it. It is a loss anyway you look at it. I have come to look at vehicles and buildings as commodity. I have read a few pos regarding the 600’s

[2-Nickels]

Originally Posted by Piros1

Well I am in the market for a newer coach, I presently own a 2005 CC with a C13 Cat 525HP. Looking for a coach with a few things mine does not have and cannot add or at least I am told they cannot be added. So my question is what engine to look for? With all the issues I hear regarding the ISX600 I am leaning toward the ISX500. I do not think I would be happy with the ISL450 after have my 525 Cat. The ISX500 is only 25HP less and about the same torque as I am use to. Since Cummins pretty much owns the RV market these days unless you want a Prevost I am not sure what to look for. I have seen a few post regarding the 600 and I do not think I am willing to take the chance that I will not have the same issue. It would be different if Cummins was willing to step up and take responsibility but I am not ready to shell out $30,000.00 to $50,000.00 for an engine with low miles. It would be a lot different if it had 300,000 plus miles on it. Any good educated info would be great. Not really looking for opinions just facts and experience. Thanks in advance.

Good morning Piros,

What are you looking for in a new coach that cannot be upgraded in your current one?

[tom chelbana]

Hard to beat our 18 London Aire with Cummins X15 605 with the Spartan K3 chassis and the 7.5 miles per gallon millage at 58K LBS. X15 is replacement for the ISX with many changes.

[Piros1]

Originally Posted by 2-Nickels

Good morning Piros,

What are you looking for in a new coach that cannot be upgraded in your current one?

I am looking for a king bed, hydraulic leveling and a both dinette to start. All three are impractical or not possible to add to mine. This is just the start. I have a list.

[Mr_D]

By hydraulic leveling do you mean jacks?
I've had the jacks and now only air leveling. I prefer the air leveling and haven't found a site I couldn't level on. There's about 8" diff between high and low which has been enough so far.
You should be able to change to a booth too. The king bed is tougher due to space. I have a king and wish I had a queen. Mine would be relatively easy to change though.

[Piros1]

Originally Posted by tom chelbana

Hard to beat our 18 London Aire with Cummins X15 605 with the Spartan K3 chassis and the 7.5 miles per gallon millage at 58K LBS. X15 is replacement for the ISX with many changes.

Tom I hear what you are saying on the 2018 Newmar London Air, but that product is out of the reach of my pocket book. I’m trying to stay under $350,000.00 if at all possible. I really can’t justify spending $500,000 plus on a new coach. I’m just using that figure lightly because I know new ones are a bit higher. I looked at some 2016 and 2017 that were in the $500,000 plus range and I’m sure any 2017 and newer will be out of reach. They are nice coaches as best I can tell though.

[Piros1]

Originally Posted by Mr_D

By hydraulic leveling do you mean jacks?
I've had the jacks and now only air leveling. I prefer the air leveling and haven't found a site I couldn't level on. There's about 8" diff between high and low which has been enough so far.
You should be able to change to a booth too. The king bed is tougher due to space. I have a king and wish I had a queen. Mine would be relatively easy to change though.

In a perfect work Mr. D I would like to have both jacks and air.
I sure hope they get your engine fixed once and for all. I keep thinking about your situation and wondering if I should keep what I have. Probably save me a lot of money. Just start leaving the wife at home and travel alone. Ha ha!

[tom chelbana]

Not a 2015 London AIre because no Star Chassis but either a 16 or 17 London Aire on a Spartan chassis would be great and can be purchased in 350K price range.