ISX 600 questions

[Duoglide1]

So far almost every one that I have found are 2009 models? So is it because of the DPF etc are is it inherent to the DOHC models? I would sleep better if I had an ISM I think. I don't know that my CM870 is any more dependable than the CM871.


2007 Monaco Executive 45' 525 ISX

[Randyman1]

Duoglide1 when I was researching this coach over 2 years ago, everything I read about this engine was fantastic. Part of my decision to purchase. I'm still going with that and the results I have been getting are fantastic as well. A friend of mine has one of these engines de-rated to 450hp, from the factory, in a Kenworth that used to be a FedEx over the road semi-truck. He is using it on the farm hauling crops to market. It has over 400k miles and no problems. No need to create ulcers when no reason to. Randy

[RVNewbie55]

Originally Posted by Randyman1

Duoglide1 when I was researching this coach over 2 years ago, everything I read about this engine was fantastic. Part of my decision to purchase. I'm still going with that and the results I have been getting are fantastic as well. A friend of mine has one of these engines de-rated to 450hp, from the factory, in a Kenworth that used to be a FedEx over the road semi-truck. He is using it on the farm hauling crops to market. It has over 400k miles and no problems. No need to create ulcers when no reason to. Randy

Randy, It's interesting you found everything great about this engine in doing your research. I found the exact same thing when doing my research before we bought this coach last December. I only began reading about problems around this past Mar. Or Apr. It was part of the reason I then bought an extended warranty. It seems the problems just did not get much attention until a few people like Mr. D. posted his problem and then it seems more people joined in with either their own story or that of someone they knew. I for one, hope this string stays alive and someone will convince Cummins to stand up and offer a no-cost, or, a very low-cost solution. Someone said that Cummins has a new head that can take the heat, but I'm sure it's not cheap.
Bob

[Mr_D]

Originally Posted by Duoglide1

So far almost every one that I have found are 2009 models? So is it because of the DPF etc are is it inherent to the DOHC models? I would sleep better if I had an ISM I think. I don't know that my CM870 is any more dependable than the CM871.

Friends of ours bought a '07 Essex with the ISM 500. Right after he bought it they had engine trouble. Don't remember what it was but he was lucky and had bought a service policy. I think it paid out more than the policy cost.

[Duoglide1]

It is only my opinion but I don't think Cummins will do anything to help. They've already decided it was a bad design and have gone back to the single cam engine. Unless they believed that these failures were going to tarnish the X engines reputation bad enough to cost them sales they have no reason to. They can already show prospective buyers for trucking companies that they have fixed it by going back to the single camshaft. I could be wrong but I suspect we are all on our own. The upside is I believe it is an overall very small number of however many units that are out there. Many of the owner-operators are not seeing any issues prior to 400000 miles and even then it's more maintenance required than failure related. I am going to drive mine, maintain it and sample everything. Good luck to all.


2007 Monaco Executive 45' 525 ISX

[Mr_D]

Well, it certainly will affect those of us that own one of the problematic ISX's! Who will buy a MH with that engine if they are known to drop valves or valve seats after a few thousand miles? That certainly undermines any future resale value. Had we known we wouldn't have purchased the rig, and now that the word is getting out what will it do to us? I'm almost 69, the DW will be 68 next month and has liver cancer so we may have to sell it sooner than planned and not be able to use it for much longer.

[Pro55]

Installing a complete recon isx 650 in my 2009 exec after it broke a valve in #6 ..I don't want to gamble with old motor...only had 15,000 miles...bill will be around $50,000...no word of cummins helping yet...I have let a lot of truck owners friends of mine know...maybe if cummins hears enough bad press they might step up...it sounds like from my research cummins is well aware of the isx 650 problem.....also went to get a extended warranty for 3 years in addition to the standard 2 year with the recon motor and cummins said that will still only be a three year coverage not 5 years, go figure!...please keep this thread going..some heavy hitter truckers are contacting cummins.. Hope that helps!... Missed a rally , car show, and a race so far.. Will be glad to get my MW back ... Must say Brian at Rocky Mountain Cummins in Albuquerque has been great to work with...if you ever have trouble take your MHZ to them...have hookups for electric and everything...Thanks

[RVNewbie55]

Please let us know what Cummins says if/when they respond...

[JMonroe]

How did this thread devolve from questions about the ISX 600 to one on the known issues with the 650?

Bottom line, I'm not aware of any systemic negative issues with the 600, which is what the OP was asking about. Anyone else?

[Mr_D]

Ummm...possibly because the same problems exist with the DOHC 600 as the DOHC 650?

However, the newer single overhead cam seem to have eliminated the problems but Cummins no longer has a 650 for the RV market either.

[Just For Fun]

Originally Posted by pasdad1

Sure. This is just one example....more out there.

RV vehicle warranty coverage, RV repair, mechanical breakdown insurance program – Good Sam Extended Service Plan

Attachment 111229

Has anyone had "personal" experience with Good Sam Warranties for major engine repair work???

Would they take on a known problem engine and warranty it for known issues???

[Mr_D]

When we finally got the service policy bid from the dealer (after the engine blow up) it was about $9,000 for four years.

[IASM]

I have an 08 isx 600 and its been a great engine. I have spent my entire working career around diesel engines and am not worried about this engine. If I were to need to replace my current rig I would be looking for the same engine.

[Mr_D]

I wasn't worried about the ISX 650 either, till it blew up! When it runs it's a fantastice engine, just worried about it staying together!