Community Forums

kid gilmore · 03-22-2023, 08:07 AM

When did the 605 HP go into RV production was it 2017?
Can you comment about the quality of the X15 thin thats 500 HP and the 605 HP.
Thanks very much!
Jeff

jacwjames · 03-22-2023, 08:35 AM

Not sure when it went into production and which one is the best but I do know there are problems with several of the ISX models.

I did a search for "Cummins ISX dropped valve" and got lots (and lots) of hits. https://www.google.com/search?q=Cumm...=irv2.com#ip=1
This is a known problem in the higher HP models but even in the 500hp but not as common.

So do lots of research, there is a fix but it is expensive.

Back several years ago I read of an individual who bought a used top end DP and it dropped a valve on their maiden voyage.

shootist · 03-22-2023, 08:45 AM

They haven’t built one yet. Talk to independent mechanics, they would never own one

bentjm · 03-22-2023, 10:55 AM

Quote:

Originally Posted by kid gilmore

When did the 605 HP go into RV production was it 2017?
Can you comment about the quality of the X15 thin thats 500 HP and the 605 HP.
Thanks very much!
Jeff

The 500 hp Cummins is the ISM 11 liter engine. It is not the ISX (X15).

KenZ71 · 03-22-2023, 12:27 PM

My King Aire has the ISX15 with 605 ponies. Was listed by https://motorhomefinders.com on Bus-Stuff Luxury Coaches For Sale

Once you find one you like can ask for the engine serial number then ask a local cummins shop to confirm the motor has had all recalls done and the drop valve issue is not a concern or was taken care of. My understanding is if it is taken care of it is a non event.

Complaints with the King Air.... the hydraulic jacks stink. Would prefer an air system that monitors and adjusts while parked. It does this while driving. Otherwise I love it. Would sell the stick house in a minute flat if the wife would let me.

When I was shopping for this beast had a couple Prevosts on my list at Olympia Coach in TN. However they did not return multiple calls or emails. Motorhome finders was quick to reply and very helpful. NewCoast financial also very helpful with finance.

RVers are usually friendly. Go to campgrounds walk around and strike up conversations if you see something that looks appealing. Never know could get insight, a tour or it might be for sale.

kid gilmore · 03-23-2023, 05:41 AM

Thanks so much for your insight. I need to study up some more. I did not think the 605 HP came out to King Aire until 2017 yours is a 2012?
I have read 9So far) that the 605 HP addressed the drop valve and was a good engine.
I have always wanted a King Aire but want and now years close to a purchase I think it best to look at other similar brands I like the Zephyr and also Entegra but hate and double hate Thor. Thank you again!

KenZ71 · 03-23-2023, 07:29 AM

Quote:

Originally Posted by kid gilmore

Thanks so much for your insight. I need to study up some more. I did not think the 605 HP came out to King Aire until 2017 yours is a 2012?

Just rechecked the brochure, I keep a copy on my phone for reference, engine is listed as 600. Yes it is a thirsty beast but also able to pull 15,000# of trailer. If towing a car hauler that is beneficial.

kid gilmore · 03-24-2023, 05:30 AM

No trailer planned but who knows maybe a dingy someday?
you at 6 gpm?

RVFunlovers · 03-24-2023, 05:26 PM

My 2017 Entegra Cornerstone had the 600 HP ISX. My 2022 Cornerstone has a 605 HP X15 motor.

I have not had any engine problems with either motor.

KenZ71 · 03-25-2023, 05:58 AM

Quote:

Originally Posted by kid gilmore

No trailer planned but who knows maybe a dingy someday?
you at 6 gpm?

If I keep speed to 75 I see about 6.5 MPG.

My 2005 Phaeton with a Cat C7 gave about the same MPG but that was much slower. The King Aire / Cummins gives me 3x more tow capacity and 5 extra feet of length

hypoxia · 03-25-2023, 08:17 AM

Quote:

Originally Posted by KenZ71

If I keep speed to 75 I see about 6.5 MPG.

If I go downhill I might see 6

That's at 62,000 pounds with the 600HP ISX. Coach is 56,000 and toad is 6,000.

RVFunlovers · 03-25-2023, 07:00 PM

I get between 7 and 7.4 MPG with my x15.
That is without generator or Aquahot heater running.
52,000 pound coach with 4500 pound tow vehicle.
Running between 65 and 73.

Less in mountains.

KenZ71 · 03-28-2023, 07:08 PM

We didn't buy these beasts for their MPGs

My goal was complete comfort while living in it for extended trips. As luck would have it the coach is now home 5 to 6 nights a week. I'm cranky when not in the coach.

2-Nickels · 03-30-2023, 11:36 AM

Our 09 ISX has averaged 6.8 MPG over the past 25,000 miles. We now have 36,000 miles on it with the replaced head and new pistons. The motor never failed but with the reading I did it was right to prevent the pending trouble. No issues with it. The EGR cooler they replaced in 2017 failed in 2022 (there was a TSB on this) and we had to replace it, the turbo and VGT in 2022.

We are on the Cummins Christmas card list

.