Used Cummins Diesel Questions

[Wilbur]

Thinking about buying an older motorhome (100K miles or less) with Cummins but not sure something(engine) won't be masked at purchase to be a problem after writing the check. Internet sites list a lot of things to look for, but want owner/operator feedback. Also, what is the average yearly cost of ENGINE maintenance when driving is 5-10K miles per year? I'm fairly good at working on gasoline engines but no experience with diesel. Any info will be appreciated!

[Ductape]

Diesel repairs may be infrequent, however they certainly are expensive. How can someone with no history of repairs be an authority on the costs of something not experienced?

[janstey58]

X2, plus you cant beat the CCC, towing capacity, Air suspension ride (versus the truck like bone shattering ride of my old gasser!) and quiet rear engine operation of the DP. I'll never go back! Plus I get 10mpg versus 6 in the former gasser.

[Tom_Barb]

Camping friends coming up on 250,000 miles on their 2002 Newmar Essex, normal tires brakes, and oil changes, not single major issue in all those miles.
I helped wash and wax this spring, it looks new.

buy smart, not often.

[Tom_Barb]

MrWizard wrote:

i had three gassers before this diesel, i have sunk more REPAIR money in this diesel than i did 'TOTAL' for all three gassers

drive train repairs for a diesel are a small fortune compared to avg gasser

Sure would like to know what Diesel you bought.

I've yet to have a drive train problem with my Spartan chassis. Cummins 8.3 350 ISC, Allison 6 speed tranny, IFS front Axel.

[gutfelt]

seriously If your not after a superior Class A Motorhome like a Allegro bus or a Newmar dutch star or a entegra or a Monaco dynasty etc

theres most certainly nothing wrong with a ton of the new Class A gassers out there today
its all about your needs:: expectations and "BUDGET" buy what you can afford not what you want

[MrWizard]

Tom/Barb wrote:

MrWizard wrote:
Cummins is reliable, until something fails
Then the diesel parts get expensive
Several grands for a turbo
More for an injection pump
The least expensive thing on this Cummins was the water pump $54 plus labor, it is an itty bitty thing, everything else cost out the wahzoo
Cummins is one of the best engines around, but those unexpected repairs can really dent the pocket book if they happen

Do you really believe the hoses, filters, oil, are any cheaper than the gas?
try buying parts for a V-10.
my life time serpentine belt for the cummins was 28 bucks, I'll never have to buy another.

buy smart not often.

those are NOT engine parts, those are disposable items, that have to be replaced on a regular bassis

i had three gassers before this diesel, i have sunk more REPAIR money in this diesel than i did 'TOTAL' for all three gassers

drive train repairs for a diesel are a small fortune compared to avg gasser

the next one will be a gasser with a FORD engine

[gutfelt]

Tom/Barb wrote:

gutfelt wrote:
oil and filter on a gasser is cheap real cheap compared to a ISL Fleetwood oil filter is 38$ and requires 26 quarts of oil verses maybe 6 on a v10

And how often? 15-20k on the diesel, how many times in that distance in a gasser?

7-8K on gasser so 2 times = 12 quarts and two 6$ filters still a lot lot cheaper oil change wise on a gasser compared to my ISL cummins

[Tom_Barb]

gutfelt wrote:
oil and filter on a gasser is cheap real cheap compared to a ISL Fleetwood oil filter is 38$ and requires 26 quarts of oil verses maybe 6 on a v10

And how often? 15-20k on the diesel, how many times in that distance in a gasser?

[gutfelt]

oil and filter on a gasser is cheap real cheap compared to a ISL Fleetwood oil filter is 38$ and requires 26 quarts of oil verses maybe 6 on a v10

[Tom_Barb]

MrWizard wrote:
Cummins is reliable, until something fails
Then the diesel parts get expensive
Several grands for a turbo
More for an injection pump
The least expensive thing on this Cummins was the water pump $54 plus labor, it is an itty bitty thing, everything else cost out the wahzoo
Cummins is one of the best engines around, but those unexpected repairs can really dent the pocket book if they happen

Do you really believe the hoses, filters, oil, are any cheaper than the gas?
try buying parts for a V-10.
my life time serpentine belt for the cummins was 28 bucks, I'll never have to buy another.

buy smart not often.

[Ivylog]

I bought the center section of the turbo on my ISL for less than $200. Many shops want you to buy the complete turbo for 10X that price.

[path1]

If your going to start getting your hands dirty, which is kind of fun actually...

When I started playing around with 5.9 (they are in a pick up's and older motorhomes) here are the tools I ended up buying. Some other specially tools might be necessary for newer models. You'll find out.

Service manuals...they cost a fortune. E bay sometimes has them, hard copy if you can or CD. With labor costs over $100.00 an hour, they pay for themselves quickly. $50-$300

Fuel pressure tester... mechanical with along hose with a needle valve. Even if you have a built in gauge, still need one to verify your on-board gauge (or scan gauge). $40-$80

Couple thin bladed wrenches to get bolts off in really tight places. $30.00

Tools for pulling Injection pump $30.00

Injector puller stuff $ 50 ( or make your own)

Better quality volt meter (while harbor freight type is OK for a good guess on something, electronics on modern diesels can be complicated and down to the .02 level $150

Bigger oil drain pan for changing oil $15.00
A big mondo oil filter strap wrench $12.00

Replaced my cheapie torque wrench with better quality $60.00

Santa going to bring me a deep well 3/8 socket set that is 12 point

I've meet a retired Cummins engineer and now after hours of talking, all my maintenance items are by the book minus 10 percent, Example if something is due at 10,000 miles, I service the item at 9,000 miles.

When stuff does break, mostly strap on stuff that is easy to fix...(starters, alternators, belts, etc) but hard to get to sometimes.

There are several tests you can do before buying to make sure or at least a good guess that nothing major is wrong with the engine before buying.

Most of break downs I've seen in RV's is due to owner not keeping up on stuff IMO.

On the computer we travel with, I've got every trouble code and how to fix listed. Complete wiring pic's

I feel I know very little but diesels because the more I learn, the more I understand just how much I don't know. But at the same time, I notice when someone is working on their diesel and I ask if they need a hand that I know more than most. Cummins employees has many engineers, so don't let some hack mechanic or local part store guy talk you into jerry rigging something.


Hope this helps

[gutfelt]

janstey58 wrote:
For those of you that put 4-5K miles a year on your Cummins DPs, do you change oil every 2-3 years, or annually? Does it hut a Diesel to sit over a winter with 4-5K miles on it when it can go 20K between oil changes? Thx, Jeff

absolutely does not hurt a thing; done it for years : have read reports where oil was tested after 4 years and was fine
lots of nay sayers out there but to each their own; its what I do and have done for years ; cummins of course(to cover to butt on warrentys)
will say 20K miles or one year;

[janstey58]

For those of you that put 4-5K miles a year on your Cummins DPs, do you change oil every 2-3 years, or annually? Does it hut a Diesel to sit over a winter with 4-5K miles on it when it can go 20K between oil changes? Thx, Jeff

[MrWizard]

Cummins is reliable, until something fails
Then the diesel parts get expensive
Several grands for a turbo
More for an injection pump
The least expensive thing on this Cummins was the water pump $54 plus labor, it is an itty bitty thing, everything else cost out the wahzoo
Cummins is one of the best engines around, but those unexpected repairs can really dent the pocket book if they happen