Trailer Life Magazine Open Roads Forum: ISX 600 HP Cummins engine pros or cons
Open Roads Forum Already a member? Login here.   If not, Register Today!  |  Help

Newest  |  Active  |  Popular  |  RVing FAQ Forum Rules  |  Forum Posting Help and Support  |  Contact  

Search:   Advanced Search

Search only in Class A Motorhomes

Open Roads Forum  >  Class A Motorhomes  >  Maintenance Issues & Tips

 > ISX 600 HP Cummins engine pros or cons

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 3  
Next
Sponsored By:
daveb1256

Nebraska

New Member

Joined: 10/21/2018

View Profile


Offline
Posted: 02/16/19 11:50am Link  |  Quote  |  Print  |  Notify Moderator

We are considering purchase of a 2006 Monaco that has the Cummins 600 HP ISX engine. Has anyone had experience with this engine, maintenance issues, recalls or any pros or cons. This engine currently has 1050 hours or 38K miles on it, appears to be very clean with no leaks or other observable problems.

Johnny G1

Clearwater, British Columbia ,Canada

Senior Member

Joined: 11/13/2003

View Profile


Offline
Posted: 02/16/19 12:01pm Link  |  Quote  |  Print  |  Notify Moderator

Its in just about every truck on the road that is pulling heavy loads, so can't be much wrong with it.Definately not needed in a 50,000 lb mh.


98 Mountain Aire 34' 210 Cummins Puller and 2001 dodge dully with all the toy's, 400 + hp pullin a 28' 5th wheel Travel Aire. Lots of fun.

2oldman

Ca

Senior Member

Joined: 04/15/2001

View Profile


Offline
Posted: 02/16/19 12:17pm Link  |  Quote  |  Print  |  Notify Moderator

2003 Monaco with ISX post

Ivylog

Blairsville, GA and WPB, FL.

Senior Member

Joined: 06/30/2004

View Profile


Offline
Posted: 02/16/19 02:11pm Link  |  Quote  |  Print  |  Notify Moderator

The good news is it’s not a 2007 or later ISX...I made sure my 08 Navigator had a 2006 engine, BUT I was not aware of the following problem. On another forum there is a lot more info on the ISX dropping the #6 intake valve to the tune of $30K in repairs. No good reason why and it’s more with the 600/650HP engines and 07 and later. More info here: ISX #6 valve breaking Some think it’s the gasses from the EGR that weakens the stem of the valve but why is it only #6 and mainly in MHs and not often in trucks?

My ISX is a 525 HP with 47K miles and I may drill a hole opposite the #6 in the intake manifold to look at the stem of that valve. If it is pitted (hopefully not) there are new valves and seats for the ISX but you are still looking at $20K+ to install.

I had to have a 08 MH because of a 10 year rule where we snowbird and Monaco did not make any 08s with the Detroit 60 engine. I would only buy a big Monaco with a Detroit 515 HP engine. Too many expensive unknowns with a ISX, especially the higher HP engines.


This post is my opinion (free advice). It is not intended to influence anyone's judgment nor do I advocate anyone do what I propose.

08 HR Navigator 45'
Sold 04 Dynasty after 14 great years.
How I tow.
Towing a Prius without a dolly
How I spend the winter.

Tom/Barb

Oak Harbor, Wa

Senior Member

Joined: 10/16/2009

View Profile



Good Sam RV Club Member


Posted: 02/16/19 02:16pm Link  |  Quote  |  Print  |  Notify Moderator

Johnny G1 wrote:

Its in just about every truck on the road that is pulling heavy loads, so can't be much wrong with it.Definately not needed in a 50,000 lb mh.


Yeah, but it is sure nice to be able to pull out and go around up hill traffic any time you choose.

ISX cummins dependable as it gets. and probably just passed its second oil and filter change.


2000 Newmar mountain aire 4081 DP, ISC/350 Allison 6 speed, Wrangler JL toad.

Ivylog

Blairsville, GA and WPB, FL.

Senior Member

Joined: 06/30/2004

View Profile


Offline
Posted: 02/16/19 02:34pm Link  |  Quote  |  Print  |  Notify Moderator

Run unless you can buy the 2006 Signature with a ISX 600 for less than $100K. A 06 Sig with a Detroit for $130K, yes. I paid $165K for my 08 Navigator a year ago.

hypoxia

Arizona

Senior Member

Joined: 04/29/2003

View Profile



Good Sam RV Club Member

Offline
Posted: 02/17/19 05:50am Link  |  Quote  |  Print  |  Notify Moderator

My 2007 Coach with a 2006 ISX, EGR but not DPF, has 83,000 miles and running strong.

Who knows what lurks inside any engine. There have been some valve corrosion problems reported. I'm waiting for Lvylog to drill and report.

Some are working the purchase deal to allow them to replace the head pre-emptively sharing the cost with the seller.


Jim

2007 Monaco Signature Noble III ISX 600HP

Ivylog

Blairsville, GA and WPB, FL.

Senior Member

Joined: 06/30/2004

View Profile


Offline
Posted: 02/17/19 12:28pm Link  |  Quote  |  Print  |  Notify Moderator

Well, like so many things in life, there is not your normal intake manifold on the ISX. The air disappears into the side of the dohc head in the middle...doubt you could get a camera to make two 180 degree turns. Maybe there is a camera that looks sideways on a flexible rod as size would be less of a problem coming in the 4” diameter hole on the side of the head.
*I see you can buy a $25 lighted borescope with a mirror on the end.

* This post was edited 02/17/19 12:45pm by Ivylog *

JaxDad

Greater Toronto Area

Senior Member

Joined: 08/02/2011

View Profile



Good Sam RV Club Member

Online
Posted: 02/17/19 01:18pm Link  |  Quote  |  Print  |  Notify Moderator

daveb1256 wrote:

This engine currently has 1050 hours or 38K miles on it, appears to be very clean with no leaks or other observable problems.


My only question with that engine would be the hours, especially when it was new’ish.

If you do the math 38k miles over 1050 hours means the average travel speed of its whole life is a whopping 36 mph.

I don’t know of too many DP MH’s used as daily commuters / grocery getters. They run the highway for hour upon hour until they reach the destination.

For a unit like that the only explanation for an average speed that low is that it spent a LOT of time idling.

Mr.Mark

Out West and Mid South

Senior Member

Joined: 09/24/2006

View Profile


Offline
Posted: 02/17/19 03:36pm Link  |  Quote  |  Print  |  Notify Moderator

Ivylog wrote:

Well, like so many things in life, there is not your normal intake manifold on the ISX. The air disappears into the side of the dohc head in the middle...doubt you could get a camera to make two 180 degree turns. Maybe there is a camera that looks sideways on a flexible rod as size would be less of a problem coming in the 4” diameter hole on the side of the head.
*I see you can buy a $25 lighted borescope with a mirror on the end.


Ivylog, I follow that thread on the other website you were referring to. Why don't you get an oil analysis to see if that can give you some info. That's how the guy that is needing is 2nd repair found out that it's happening again.

I sure hope that you never have to worry with that repair.

Safe travels,
MM.


Mr.Mark

2015 Prevost Liberty Coach, 45 ft, 500 hp Volvo w/1,750 lb. ft. of torque, 1.5 baths, 4 slides.
2017 Lincoln MKX AWD V6 335 hp twin turbo.

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 3  
Next

Open Roads Forum  >  Class A Motorhomes  >  Maintenance Issues & Tips

 > ISX 600 HP Cummins engine pros or cons
Search:   Advanced Search

Search only in Class A Motorhomes


New posts No new posts
Closed, new posts Closed, no new posts
Moved, new posts Moved, no new posts

Adjust text size:

© 2019 CWI, Inc. © 2019 Good Sam Enterprises, LLC. All Rights Reserved. | Terms of Use | PRIVACY POLICY | YOUR PRIVACY RIGHTS