2007 CC 45ft Magna 600HP ?????

[roberto]

So, have a 2002 CC 36 ft now. Looking at a 2007 45 ft Magna with the 600 hp Cummins. Reading the posts on the large MH Cummins engines has me questioning the reliability of this 600 hp unit. Coach has less than 50K miles.
Would this be a safe buy based on the engine or pass?
Thanks, Bob
02 Allure 36 ft SRTS. 350 Cummins.

[oakcreekeric]

I believe there have been a couple threads about dropped valves on that engine.. not sure exactly what years.. but worth looking up..

http://www.irv2.com/forums/f115/drop...sx-367784.html

http://www.irv2.com/forums/f123/isx-...me-238170.html

http://www.irv2.com/forums/f123/more...ve-242822.html

If you reach out to Mr D - He is very knowledgeable on this subject

[IASM]

hello
There are literally thousands of isx600 engines out there and i have never heard of a real issue that could be traced to a design problem. There have been some instances of dropped valves in the isx-650 hp engine. I have not seen this engine used in the trucking industry but it is used in a lot of rv. When i upgraded to my current motorhome the isx-600 was on my list of wants. Most of the 600s used by country coach were older engines so they are def. On my 08 coach i have an 06 engine. .
With these big block engines irregardless of brand heat needs to be recognized. It takes 15 to 20 minutes for the block to equalize so one should refrain from being to aggressive with the throttle until you are confident the block has stabilized. Same goes for shutdown . Several minutes before you reach your destination slow down and take it easy on the fuel.

My comments are based on being in the trucking industry and experience with both cat and cummins.
If your looking at a coach i would be concentrating on the general condition and how it was maintained.

[Willee]

I've had a CAT C9, a Cummins ISL 400hp and now have a Cummins ISX 600hp. I'll simply state, there is NO substitution for lots of torque, period. I will never go back. The ISL is a nice engine but a simple explanation is .... same mountain grade, same tow car, same gear on board ... ISL - 35 mph vs ISX - 55 mph. That says it all.

Stay away from the ISX 650 hp. You can have a good one and then suddenly one day it will suck a valve and now you are stuck for some BIG $$$ to repair.

If you have any questions about the engine in the coach, you are looking at, arrange to take it to a Cummins shop. They will plug in a computer and print out an entire history on that engine. You'll know everything that has happened to it throughout its entire life. They do charge for this service. They will also be able to tell you if there have been any factory recalls/repairs on the engine.

I know a lot of Magna & Affinity owners that have the 600 hp ISX and none have had any issues with the engine. Other issues, yes, but not the engine.

You will not be disappointed driving a Magna with 600hp. The first thing you will notice, over your old coach, is that when you push down on the accelerator, the coach actually accelerates rather than slowly thinking about picking up speed.

I've gone over a 11,800 foot pass in the Rockies doing 45 mph (because that's all the curves allowed me to do) and there was not a noticeable loose of power at altitude.

FYI-I drive and 08 CC Affinity towing a Jeep Grand Cherokee

[roberto]

Thanks for the feedback. Coach is in great condition. Only has a couple of windows that are foggy. I read the links covering the ISX 650 units failing with the 'code black' repair bill.
Looks like this engine(600 hp) is a pretty safe bet for a serious review. Good idea to have Cummins do a scan for problems. Oil sample seems in order, too.
I really appreciate the description of the acceleration difference of the 400 vs the 600 hp units. The new coaches are generally the 400-450 hp units with DEF.

Thanks again, Bob 02 CC 36 SRTS 350 Cummins

[Mr_D]

The 600 does not seem to have the valve breakage problems that the 650 does. I've gotten two stories on it. One that they used the same head and valve as the 600 and it won't take the extra heat stress. The other was that they used a new head and valve design and it wasn't correct.
Now they have a new head, valves, turbo and ECM programming. Once the engine is rebuilt with the correct parts it seems to be as reliable as any other Comeapart (Cummins) engine. I've been doing oil analysis on mine with no bad reports yet.

[Mr_D]

Originally Posted by oakcreekeric

I believe there have been a couple threads about dropped valves on that engine.. not sure exactly what years.. but worth looking up..

http://www.irv2.com/forums/f115/drop...sx-367784.html

http://www.irv2.com/forums/f123/isx-...me-238170.html

http://www.irv2.com/forums/f123/more...ve-242822.html

If you reach out to Mr D - He is very knowledgeable on this subject

I don't know about being knowledgable about them but I do have a lot to say about Cummins lack of support when owners have an engine failure obviously caused by a poor design and testing.

[roberto]

Mr D: It's almost as if Cummins bills MH owners as business units capable of 'writing off' our repair bills as expense items for the IRS. Plus, the 650 engine failure appears to be a design failure and not a lack of normal maintenance.
MAYBE we will see an EV MH replacing all ICE power units? Mercedes just announced their full electric city bus.
Thx for the feedback.
Bob 2002 CC SRTS Allure 36

[Mr_D]

Check the Cummins engine section for another dropped valve in #6. But this time it's the 600 hp version. Seems like there may be more coming out as mileage accumulates.

[roberto]

Mr. D: THX. Read the posts you referenced. As you say, mileage over time will tell the complete story. Did I read these posts correctly in that these ISX engines need to be 'worked' harder? RV life for the ISX needs more activity on the road? If this is true this would be an interesting design challenge. Then again, the new head design has been implemented.
Haven't looked into the trucking world exposure.
Think I'll go ahead and install a residential frig on my CC and call it a day.
Bob 2002 CC SRTS 350 Cummins