MarYJac04

Cummins ISL 9 Maintenance and Mileage Questions

8 posts in this topic

I have been looking at a short Journey and ran across I nice 40 foot Monaco we really like. It is both larger and has a bigger engine than we have ever thought we would consider. The engine is a 400hp ISL9 and vehicle GVWR is 35000 lbs.

Can anyone give me some idea of annual engine maintenance costs and what mileage I might expect; will be towing a CRV.

I see oil changes are every 12 months and I am wondering if that is necessary when using synthetic oil, or can an oil analysis be used to determine change time?

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I will address the oil change question.

All diesel manufacturers recommend annual oil changes regardless of mileage.

Can you go longer using oil analysis without harming the engine-- perhaps. Depends on a lot of factors such as humidity and temperature where stored, highway vs short distance driving, number of miles etc. Disregarding manufacturer's written recommendations would be up to you.

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I believe Cummins is 15,000 miles or 1 year, whichever occurs first. Then there is the chassis maintenance schedule based on miles and the manufacture web site has the schedule. example: Freightliner chassis.

I typically plan on 1000-1500 dollars each year if Freightliner does all the work. If you are able to do the oil/filter changes yourself and keep the receipts you can save money. Personally I prefer to have the experts do it because they can pick up little things that I may not notice.

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Thank you for the response, that is just about what I expected. I have heard concern about purchasing an "orphaned" coach and was wondering if that is a valid concern.

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You should change you oil at least once a year, so if you run less than than 15000 miles you can save a little money using a good brand name diesel oil ( sams club sells Shell Rotella T) and buying your filters online from someone like truckhelp.com Buy enough to get free shipping which by the time you get all you filters ( including generator ) and a spare set of fuel filters to carry with you, you should reach that . As far as mileage you should get somewhere between 8 and 9 mpg towing . It will tow your crv like its not even there.

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Thanks for the additional information. I have an additional question. I test drove the the Camelot yesterday and was not able to determine if or how much the air suspension hieght raised after starting the engine. After returning I watched for lowering the height off the ground when the engine was shut down or air dump switch was used.

Should I be able to see this?

How much difference in height should I expect?

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Our 2 diesel pushers dropped down around 6" when I dumped the air. I'm sure it varies from coach to coach but my opinion is 4"-8" and YES, you definitely can tell the difference in height when the air is dumped.

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We have a 400 HP ISL, MH GW is 34,600 and we tow a CRV. Overall MPG is around 8. A headwind hurts our mileage worse than anything else.

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