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mikron 09-19-2011 04:30 PM

Low miles on a diesel
 
Been looking at DPs on ebay and notice most diesels for sale that are 4 to 8 years old have less then 20,000 miles on them. I was told by more then one diesel repair shop that is bad for a diesel. Average use should be 15,000 or more each year. So to all the DP owners whats up.

refncpa 09-19-2011 04:48 PM

Cost of ownership issues. Unless you are retired most people use theMH for short trips weekend trips and may have a longer trip with family. Unless you commute with MH daily or a full timer, very unusual to put that many miles on the unit.

Superslif 09-19-2011 05:02 PM

My parents have a 03' pusher with 40k. They (retired) do maybe 10 local extended weekend trips during the warmer weather here in Ohio and winter in South Texas....

mikron 09-19-2011 05:31 PM

Iunderstand some or most put few miles on a diesel. My question is that bad for a diesel. We do about 5,000 miles per year and have passed on a diesel because of the low miles. It looks like most with diesel do less then that. Is there a lot more maintenance and repair with low miles.

Tha_Rooster 09-19-2011 06:01 PM

Most rv's sit more than they are driven unless it was owned by a full timer, would be my guess. There is not more maintenance because of low miles because you are going to do it at least yearly anyway. There is no question DP are more expensive to buy and maintain. Diesels do need to be run, I go on a lot of short trips since we still work and have very low milage.

Cat320 09-19-2011 06:03 PM

Most maintenace requirements are for a certain mileage...that we normally don't get, or annually, which ever comes first. So the maint is the same. The driving is so much easier and more pleasant in a diesel than a gasser, to me it's worth the cost of the diesel over a gasser.

rvjimmy 09-19-2011 06:52 PM

I still work full time and put on average 8 to 10 thousand miles a year. We go somewhere almost every weekend and take a 2 week long trip every year. I like the diesel for the power and they have a lot heavier chassis so they drive like dream.That's my story and I'm stick'en to it.:rolleyes:

RVNeophytes2 09-19-2011 07:19 PM

Thank You! Driven DPs Are A Better Deal
 
Quote:

Originally Posted by mikron (Post 962433)
Been looking at DPs on ebay and notice most diesels for sale that are 4 to 8 years old have less then 20,000 miles on them. I was told by more then one diesel repair shop that is bad for a diesel. Average use should be 15,000 or more each year. So to all the DP owners whats up.

We saw the light, bought our 2005 in January with 84,000 miles on it. It has performed like a gem, and we've driven 6,000 problem-free miles already!

But, emotion not logic rules in the marketplace. Dealers tell me our rig is worth much less, because of the mileage. Never mind that the NADA guide says mileage doesn't enter into the appraised value of DPs (my private opinion is that documented steady use should raise, not lower, the sale price).

Unless they have no integrity, they'll also sing the same song when it comes time to sell:angel:

Buyers, you can use the effect of mileage to your advantage: buy regularly-used rigs at lower prices and enjoy better performance!

randco 09-20-2011 04:40 AM

mikron,

I would think that your 5,000 mile annual usage would be fine for a diesel. Heck that's a little over 400 miles per month average. If you want a DP, I say go for it. If you can get a good deal, go with your gut feel. Life is to short to have any regrets.

When we purchased our new to us 2004 coach the end of January this year. It had 28,000+ miles on the odometer. We have added about 8,000 miles to it in seven and a
half months. It is a wonderful coach. The ride and the handling are awesome. We get 8.5 mpg pulling a 4,200 lb toad and running the generator for the a/c.

Before I retired, I didn't put 15,000 miles on the car I drove back and forth to work every day.

H. Miller 09-20-2011 05:56 AM

To actually answer your question, I would be "leary" of a several year old MH with less than 20K miles. Did it sit for years with no use? How was it maintained? Were the annual (not mileage) maintenance requirements met?

JimmyLeggett 09-20-2011 06:54 AM

Quote:

Originally Posted by H. Miller (Post 962959)
To actually answer your question, I would be "leary" of a several year old MH with less than 20K miles. Did it sit for years with no use? How was it maintained? Were the annual (not mileage) maintenance requirements met?

in complete agreement. I bought a 05 fleetwood expedition 38N. It had 22000 miles on it. It soon became obvious that the maintenance had not been perfomed as it should have been. we (includes my son) put 16000 miles on it. On our first trip, had fuel filter problems with the inline fuel filter clogged up with grit and old fuel problems. After the fuel filter issues the engine and transmission performed flawlessly.

on my first and only long trip to Michigan, had slideout issues in Oklahoma, a/c issues the entire trip, electrical issues until we traded it.

almost all of the issues were from neglect of maintenance. No matter what you buy, be it a DP, gasser or even a 5er they are complex with many systems which must all be maintained. Running a vacumn, dusting and wiping down is cleaniness and housekeeping, it is not maintenance.

I traded the 05 for a 09 Damon Astoria with very low miles and even with a 09 model year found some issues from neglect of the coach systems but I have all of them corrected now and I am fairly happy with the coach, it should give me years of dependable service.

The point is, there is more to a MH than the engine and transmission, no matter what you buy.

Just my 2 cents:whistling:

HD4Mark 09-20-2011 07:00 AM

Ask for maintenance records if you find a low mileage DP that you like. Ours was five years old and only had 35K on it. For the first year we bought an extended service plan, even though expensive for the peace of mind. Never used it for any engine related problems but still nice to know it was there. We also have road side assistance, just in case.

One of the fears of low mileage is that starting but not running a diesel up to operating temps can create moisture inside the engine that will shorten its life. Not always easy to do if you just need to move it a few feet. A tech at Cummins said if you could not take it for a drive to idle it until it reached operating temp but they don't get warm easily just sitting. Another is that as stated some maintenance items are mileage or annual. An example is oil change. 10K miles or one year. At twenty something quarts and $30 filter makes it hard to justify when you only put a few thousand on it but the year is up. Ours has had two oil changes in the last 6K miles.

When we first purchased ours it was also our first diesel of any kind. Made me nervous never owning one and not knowing much about them. Turned out they operate very much like your gas powered MH. The exceptions are loads more power, better ride and the noise is behind you.

RoyM 09-20-2011 07:48 AM

Probably only run twice a year, south in the fall, north in the spring. We see that frequently here in the Great White North.

Pairajays 09-20-2011 09:59 AM

I think the answer would depend on the home location, ie, where it is parked when not in use. If it is located in the Eastern part of the country where high humidity and extremely high temperatures variations exist, then it "could" be a problem. But, that is a problem with any internal combustion engine, diesel or gasoline. Take this for what it is worth, IMO most of the negatives opinions, about this subject, expressed on these forums are BS. I mean no disrespect to anyone. Personal experiences may have some merit but without substantial background information, it would be suspect.

Annual oil changes, without substantial milage, is not required, IMO. Operator manuals, supplied by MH manufactures, are filled with CYA stuff. The same thing applies to engine manufacturers, to some degree. They are all based on use in extreme conditions. I winter in Yuma AZ and the MH sits for 5 months. I don't start it every month to bring it up to operating temperature. I have operated this way for years and I defy anyone to find any detrimental affects. I would think the best procedure would be to have your engine oil analyzed chemically. A $25 analysis is far cheaper than an unnecessary $200 oil change. It is my understanding that trucking company's use this procedure and can extend oil changes to one or two hundred thousand miles. One last comment, diesel powered farm equipment are often used only about three months and them sit idle for nine months and last for many years. I'm sure the owner does not run the equipment every month.

If your MH is not subjected to extreme temperature variations, while parked, then use common sense.

Jim E

mikron 09-20-2011 10:00 AM

Thanks for the replys, feel better about looking. ebays deals are mostley repos and that could be a problem.

mikron 09-20-2011 10:05 AM

Quote:

Originally Posted by Pairajays (Post 963117)
I think the answer would depend on the home location, ie, where it is parked when not in use. If it is located in the Eastern part of the country where high humidity and extremely high temperatures variations exist, then it "could" be a problem. But, that is a problem with any internal combustion engine, diesel or gasoline. Take this for what it is worth, IMO most of the negatives opinions, about this subject, expressed on these forums are BS. I mean no disrespect to anyone. Personal experiences may have some merit but without substantial background information, it would be suspect.

Annual oil changes, without substantial milage, is not required, IMO. Operator manuals, supplied by MH manufactures, are filled with CYA stuff. The same thing applies to engine manufacturers, to some degree. They are all based on use in extreme conditions. I winter in Yuma AZ and the MH sits for 5 months. I don't start it every month to bring it up to operating temperature. I have operated this way for years and I defy anyone to find any detrimental affects. I would think the best procedure would be to have your engine oil analyzed chemically. A $25 analysis is far cheaper than an unnecessary $200 oil change. It is my understanding that trucking company's use this procedure and can extend oil changes to one or two hundred thousand miles. One last comment, diesel powered farm equipment are often used only about three months and them sit idle for nine months and last for many years. I'm sure the owner does not run the equipment every month.

If your MH is not subjected to extreme temperature variations, while parked, then use common sense.



Jim E

I have read other postings saying they store for months and don't run until ready to travel. I wasn't sure what that did. We live in Florida and temp is pretty even.

randco 09-20-2011 10:27 AM

We also live in Florida. We purchased our coach at Classic Motor Coach.

They are a small family owned dealership. They mainly carry bank repo's and were great to deal with. They also post prices on their site.

Good luck in your search.

deandec 09-20-2011 10:46 AM

We bought a 7 year old DP with 26,000 miles on the odometer and 40 hours on the generator.

After our nine years and 60,000 miles of travel, it has been a great rig.

The problems that we have had to deal with are many, but not significantly diesel related. We have been towed (for free by Coachnet) two times.

Most of the fixes have been DIY and common to many other MH whether new or old.

Components replaced other than tires, fuses and batteries are:

Fuel Injection Pump
Exhaust Manifold Gasket
Engine Water Pump
Cracked fuel line
Alternator
Exhaust Brake Cylinder
CO monitor
Circuit Board on Refrigerator
Circuit Board on Water Heater
Voltage Regulator on Generator
Engine Thermostat

So, based on our experience low miles on a diesel are not such a bad thing.

mikron 09-20-2011 05:38 PM

Quote:

Originally Posted by randco (Post 963138)
We also live in Florida. We purchased our coach at Classic Motor Coach.

They are a small family owned dealership. They mainly carry bank repo's and were great to deal with. They also post prices on their site.

Good luck in your search.

Went on Classic site. They have some nice rigs and a lot closer to us from Ocala then Lazy days. Thanks.

f14av8r 09-20-2011 05:54 PM

A diesel engine will last a lot longer than a gas engine. But, most MH owners will never realize that advantage as we simply do not drive enough miles to make it worth the expense over the life of a typical MH. The ONLY reason to buy a diesel is for the nice, quiet ride, the power, and the fact that most of your bigger coaches don't give you a choice. Also, the benefit of a good quality, rigid frame (chassis) cannot be overstated. That usually only comes in a diesel configuration.

Having said all that, I'd be leary of a diesel that hasn't been run regularly if the owner can't produce solid maintenance records. I strongly disagree with Jim E on the mileage vs time issue. Your diesel needs maintenance and it needs it when either the mile or time values are reached. Filters age and fluids deterioriate over time, regardless of the number of miles run. I've seen air filters that were literally sucked into the engine because the binding straps on the filter media became brittle and let go of the media. Those are expensive repairs.

The manufacturers do not unnecessarily pad their maintenance schedules as a CYA tactic. They have every incentive to make their schedules a long and inexpensive as possible. That's how they attract the long haul crowd.

In my humble opinion, you disregard the manufacturer recommended schedule at great risk. And, I won't buy a diesel from anybody that can't demostrate they've followed the schedule - time or distance, whichever comes first.

Finally, here is a heads up. If you buy a unit that has sat on the lot for awhile, make sure the dealer did the time related maintenance that was specified by the chassis manufacturer. If not, you may be in for a big surprise when you go for your first service and find out you have quite a bit of catch up work to do.

Hope that helps!

Meandering Retiree 09-20-2011 06:26 PM

The diesel is more expensive to own and to operate, but I consider the air brakes to be an asset when traveling.

docj 09-20-2011 06:41 PM

Quote:

Originally Posted by f14av8r (Post 963510)
A diesel engine will last a lot longer than a gas engine. But, most MH owners will never realize that advantage as we simply do not drive enough miles to make it worth the expense over the life of a typical MH.

IMHO another reason many MH owners don't achieve the benefits of diesels is that they don't take care of them because they believe they are "bullet-proof". From what I read I get the sense that quite a few diesel MH owners ignore "service by time" recommendations because their mileage usage is much lower than the "service by mileage" recommendation for the same servicing.

For example, rather than changing transmission filters and fluid on a 3-4 year cycle as recommended by Allison they argue that it isn't necessary because their mileage is far lower than the 100K miles which is the "service by mileage" recommendation. The reason is usually $$; a transmission drain and refill with Transynd and filters is $400-600 depending on where you have it done. (Fluid life can be extended with oil sampling and analysis, but many people are not aware of that.)

Even if you purchase a MH with good service records (as we did) make sure that all the recommended service has been performed. As well cared for as our MH was, I have found a number of service areas which were "shortchanged" by the PO.

The bottom line is that diesels can last a lot longer than most of us will ever drive but they do require regular servicing. Diesel service can be expensive (~$200 oil changes), but ignore the service recommendations at your own peril.

bbeane 09-20-2011 07:35 PM

Bought our current MH 6 years ago with 35k on it now has 65K, and is 12 yrs old. Runs like a top serviced completely every 12 mos, regeadless of mileage. However it is old like everything else time gets to things. So part of PM service as far as the diesel is concerned over the years, rebuilt Alt and starter, belt tensioners and belts, fuel transfer pump, new T/stat with coolant change. Also checked and repaired battery cables. The moral of the story mileage doesn't affect things as bad as time. The older they get gas or diesel the more they cost to keep running. As others have said Diesels cost more to service and repair, but in the larger coaches they are a necessary evil. :thumb:

JimM68 09-20-2011 08:13 PM

Hmmm, i've read what, 3 posts here from owners of 10 year old deisel coaches that have needed gobs of serious repairs? fuel pumps and manifold gaskets and starters and things? and they call it normal?

I'd really have to say that is not normal. My 04 silverado (gas) pickup has 180k miles, on nothing but oil changes. 1 set of tires, 1 set of brakes, 1 trans fluid change, 1 set of shocks, 1 battery. I'd call this normal. Previous american cars and trucks, same same, 200k plus each with basically no problems other than wear items.

99 ford V10 pace Arrow, same same, zero problems with the drivetrain, suspension, or chassis.

Current 08 knight, bought last march with 18k, now with 29k,zero problems of any kind so far (knock wood)
I expect my knight to go a million miles on nothing but lubricants and filters, and maybe a belt. That's it. (knock wood)

randco 09-21-2011 05:01 AM

Quote:

Originally Posted by JimM68 (Post 963669)
Hmmm, i've read what, 3 posts here from owners of 10 year old deisel coaches that have needed gobs of serious repairs? fuel pumps and manifold gaskets and starters and things? and they call it normal?

I'd really have to say that is not normal. My 04 silverado (gas) pickup has 180k miles, on nothing but oil changes. 1 set of tires, 1 set of brakes, 1 trans fluid change, 1 set of shocks, 1 battery. I'd call this normal. Previous american cars and trucks, same same, 200k plus each with basically no problems other than wear items.

99 ford V10 pace Arrow, same same, zero problems with the drivetrain, suspension, or chassis.

Current 08 knight, bought last march with 18k, now with 29k,zero problems of any kind so far (knock wood)
I expect my knight to go a million miles on nothing but lubricants and filters, and maybe a belt. That's it. (knock wood)

I'm with you Jim. Our 04 Escaper we purchased in January with 28,000+ miles, now with 37,000 and zero problems. (knock wood) I expect the Cat to be going strong for many, many miles on nothing but preventative maintenance. PM being periodic changing of lubricants and filters. There may come a time when the serpentine belt needs replacement or an alternator fails but only time will tell.

Jim28730 09-21-2011 08:13 AM

Quote:

Originally Posted by rvjimmy (Post 962625)
I still work full time and put on average 8 to 10 thousand miles a year. We go somewhere almost every weekend and take a 2 week long trip every year. I like the diesel for the power and they have a lot heavier chassis so they drive like dream.That's my story and I'm stick'en to it.:rolleyes:

Amen brother! :dance:

B Bob 09-21-2011 08:32 PM

In my experience 5-6,000 miles a year on a coach is about ideal. Very low miles usually means the motor home sat for long periods which is very hard on them. I would rather buy a coach with higher miles than normal than less. But this is only on a diesel pusher. Miles on a Cat or Cummins mean little. One of my best friends bought a Dutch Star that had sat for 18 months waiting to be sold. It took him two years to get the lot rot out of it.

Pairajays 09-21-2011 08:58 PM

Quote:

Originally Posted by B Bob (Post 964623)
In my experience 5-6,000 miles a year on a coach is about ideal. Very low miles usually means the motor home sat for long periods which is very hard on them. I would rather buy a coach with higher miles than normal than less. But this is only on a diesel pusher. Miles on a Cat or Cummins mean little. One of my best friends bought a Dutch Star that had sat for 18 months waiting to be sold. It took him two years to get the lot rot out of it.

I have a 1997 Beaver which I drive about 4,000 miles per year. During the colder months it sits in Yuma AZ for about 5 months and about 5 months in Quincy WA during the warmer months. I never start the MH during those periods and have never had any problems. Is 10 months a year considered a long time? What is it that makes this kind of usage hard on the them?

Jim E

B Bob 09-22-2011 09:21 AM

What is hard about motor homes sitting for months at a time is

1. Very hard on tires to sit in same position for months.
2. Internal engine components can rust when oil not circulated for months.
3. Hoses can rot.
4. Seals like to be used.
5. Batteries like to be charged and used.
6. Mice and other creatures like to explore and build homes in motor homes sitting for long periods. This one esspecially has been a problem for me.

For sure my motor home takes about 3-4 days into a long trip before she seems to run the best.

Bob Affinity 42'

Journey 4 09-22-2011 09:45 AM

Somewhat stumped
 
Hello, I am in the process of purchasing a 2006 Mountain Aire. (13,000 miles). We were also interested in a 2008 AC Tradition which was $70,000 more. Get a call late last night and they came down $50,000. Any thoughts between the two coaches; better purchase for maintenance, quality of construction etc.
Thank you.

Mekanic 09-22-2011 10:01 AM

Quote:

Originally Posted by mikron (Post 962433)
Been looking at DPs on ebay and notice most diesels for sale that are 4 to 8 years old have less then 20,000 miles on them. I was told by more then one diesel repair shop that is bad for a diesel. Average use should be 15,000 or more each year. So to all the DP owners whats up.

Short trips are bad but only IF your engine oil and coolant do not get up to operating temp for about 30 min.
My 1994 Ford diesel I bought had only 107K on it when I bought it last fall. For a truck of that age that is also low miles.
It had sat for a couple of years.
All fluids and filters got changed as well as the fan belt. that and some new tires and it drives and runs like new.

Pairajays 09-22-2011 12:10 PM

Quote:

Originally Posted by B Bob (Post 964949)
What is hard about motor homes sitting for months at a time is

1. Very hard on tires to sit in same position for months.
2. Internal engine components can rust when oil not circulated for months.
3. Hoses can rot.
4. Seals like to be used.
5. Batteries like to be charged and used.
6. Mice and other creatures like to explore and build homes in motor homes sitting for long periods. This one esspecially has been a problem for me.

For sure my motor home takes about 3-4 days into a long trip before she seems to run the best.

Bob Affinity 42'

Well, let's see. Tires sitting for long periods can result in flat spots. I've never had a problem with flat spots on my tires when properly inflated. Deploying leveling jacks could solve that. Rusting engine components. i just don't understand that. Oil does not evaporate, if it was oily when you shut down, it's going to be oily when you start up. Even parked in high humidity areas, I doubt enough moisture could get to your engine components that would cause rusting. What causes hoses to rot when parked and not when running? I don't know what seals you are talking about. I know some seals stop doing the job, but it takes more than 5 or 6 months for this to happen. I don't understand what you mean when you say batteries like to be charged and used. Most, if not all, MHs have charging systems to keep them charged while parked. What harm will result if a battery is not used? I do agree you might have a mice problem unless your RV is well insulated against them.

What about farm equipment? They sometimes sit idle for 8 or 9 months. Do all the things you sited happen to them? What about new or used MHs sitting on dealer lots for months? I'm not implying i'm an expert on this subject, just going by my experience and using common sense as I see it. It is not unusual for folks to pass along information given to them by others with no details provided. An example would be someone, living in a New England state, leaving their RV parked uncovered during the winter months. I don't doubt the might have problems come summer.


Jim E

Full.Monte 09-22-2011 11:26 PM

Quote:

Originally Posted by Pairajays (Post 965075)
Well, let's see. Tires sitting for long periods can result in flat spots. I've never had a problem with flat spots on my tires when properly inflated. Deploying leveling jacks could solve that. Rusting engine components. i just don't understand that. Oil does not evaporate, if it was oily when you shut down, it's going to be oily when you start up. Even parked in high humidity areas, I doubt enough moisture could get to your engine components that would cause rusting. What causes hoses to rot when parked and not when running? I don't know what seals you are talking about. I know some seals stop doing the job, but it takes more than 5 or 6 months for this to happen. I don't understand what you mean when you say batteries like to be charged and used. Most, if not all, MHs have charging systems to keep them charged while parked. What harm will result if a battery is not used? I do agree you might have a mice problem unless your RV is well insulated against them.

What about farm equipment? They sometimes sit idle for 8 or 9 months. Do all the things you sited happen to them? What about new or used MHs sitting on dealer lots for months? I'm not implying i'm an expert on this subject, just going by my experience and using common sense as I see it. It is not unusual for folks to pass along information given to them by others with no details provided. An example would be someone, living in a New England state, leaving their RV parked uncovered during the winter months. I don't doubt the might have problems come summer.


Jim E

Jim,
You are lucky to live in a low humidity area. It helps you avoid some of the problems discussed. I own 3 vehicles with diesels. The problem with
leaving engine oil for long periods in an engine in non-operating status is that it collects water. Where does the water come from? It comes from the air that is above your engine sump. When the temperature drops from high to low during the 24 hour cycle, any moisture in the air condenses on the cold motor parts and exposed oil pan surfaces. It's the same phenomenon that makes your grass appear damp in the morning even though you haven't run the sprinklers. The water droplets thus formed slide down into the oil sump. Water, being heavier than oil, collects in the bottom of the sump and starts rusting your oil pan. I rusted out an oil pan from the inside this way once. Pin holes open up and the pan starts leaking. When you operate the engine frequently, the water gets heated up and comes out of the tailpipe as steam, reducing the amount of water in the sump and the damage it causes. That's why they recommend oil changes based on number of miles driven (because of oil lubrication breakdown) OR number of months (because of water contamination), whichever comes first.

You are also incorrect about battery maintenance, but that's a whole different subject.

Pairajays 09-23-2011 10:08 AM

Quote:

Originally Posted by Full.Monte (Post 965552)
Jim,
You are lucky to live in a low humidity area. It helps you avoid some of the problems discussed. I own 3 vehicles with diesels. The problem with
leaving engine oil for long periods in an engine in non-operating status is that it collects water. Where does the water come from? It comes from the air that is above your engine sump. When the temperature drops from high to low during the 24 hour cycle, any moisture in the air condenses on the cold motor parts and exposed oil pan surfaces. It's the same phenomenon that makes your grass appear damp in the morning even though you haven't run the sprinklers. The water droplets thus formed slide down into the oil sump. Water, being heavier than oil, collects in the bottom of the sump and starts rusting your oil pan. I rusted out an oil pan from the inside this way once. Pin holes open up and the pan starts leaking. When you operate the engine frequently, the water gets heated up and comes out of the tailpipe as steam, reducing the amount of water in the sump and the damage it causes. That's why they recommend oil changes based on number of miles driven (because of oil lubrication breakdown) OR number of months (because of water contamination), whichever comes first.

You are also incorrect about battery maintenance, but that's a whole different subject.

I understand the humidity and condensations process. The engine and associated oil sump are a sealed unit. I doubt any outside air can get inside the sump. The humidity of the air that is initially inside the sump would therefore remain constant because it is never exchanged.

Jim E

mikron 09-23-2011 10:22 AM

I am reading all the replys and find most think sitting not good. Living in Florida we can travle year round mostley (90%) in Florida unit always working. I get from the replys do maintenance as required no mater miles travled and I should be ok. I run my gas unit and always have every 30 to 45 days for 30 miles or so and change the oil every 6 months. With a DP it looks like I don't have to change the oil that often.

HD4Mark 09-23-2011 03:09 PM

Quote:

Originally Posted by mikron (Post 965828)
I run my gas unit and always have every 30 to 45 days for 30 miles or so and change the oil every 6 months. With a DP it looks like I don't have to change the oil that often.

Yes but your gas unit will take 7 quarts max for a 6 month change while a DP can go 10,000 the one year change period will use 3 times as many quarts and a much more expensive filter. So even though the diesel can go further and longer it is no cheaper.

mikron 09-23-2011 03:29 PM

I did understand that, but not much more for the diesel for the better ride and steady power is ok by us. I don't hate my gas coach just reading all the postings and replys how the deisel rides and handles better. Will have to up grade my lic. so I can test drive a diesel.

mikron 09-24-2011 06:56 AM

Quote:

Originally Posted by mikron (Post 966055)
I did understand that, but not much more for the diesel for the better ride and steady power is ok by us. I don't hate my gas coach just reading all the postings and replys how the deisel rides and handles better. Will have to up grade my lic. so I can test drive a diesel.

Checked Florida Lic. law, don't need any different class Lic. from driving a car (class E) up to a 45' rig for RVs only. Scarry, I feel ok drove heavy equipment trucking in service including Fargo & Brill busses.

Full.Monte 09-25-2011 07:41 AM

Quote:

Originally Posted by Pairajays (Post 965809)
I understand the humidity and condensations process. The engine and associated oil sump are a sealed unit. I doubt any outside air can get inside the sump. The humidity of the air that is initially inside the sump would therefore remain constant because it is never exchanged.

Jim E

Jim,

This is from Wikipedia:

Air ventilation

Main article: crankcase ventilation system
During normal operation, a small amount of unburned fuel and exhaust gases escape around the piston rings and enter the crankcase, referred to as "blow-by".[7] If these gases had no controlled escape mechanism, the gasketed joints would leak (as they "found their own way out"); also, if the gases remained in the crankcase and condensed, the oil would become diluted and chemically degraded over time, decreasing its ability to lubricate. Condensed water would also cause parts of the engine to rust.[8] To counter this, a crankcase ventilation system exists. In all modern vehicles, this consists of a channel to expel the gases out of the crankcase, through an oil-separating baffle, to the PCV valve, into the intake manifold. In a non-turbo engine, the intake manifold is at a lower pressure than the crankcase, providing the suction to keep the ventilation system going. A turbo engine usually has a check valve somewhere in the tubing to avoid pressurizing the crankcase when the turbo produces boost.
If an engine is damaged or enters old age, gaps can form between the cylinder walls and pistons, resulting in larger amounts of blow-by than the crankcase ventilation system can handle. The gaps cause power loss, and ultimately mean that the engine needs to be rebuilt or replaced.[7] Symptoms of excessive blow-by include oil being pushed up into the air filter, out the dipstick,[9] or out the PCV valve. In rare cases of serious piston or ring damage, the oil filter housing's sheet metal can even burst at its seam.
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So, the crankcase is not sealed. Therefore, condensation inside the crankcase can deposit water into the oil and start corroding the oil pan.
If you've ever seen an old car or truck sitting out in a farmer's field for a number of years, you might successfully wager that rust has formed in a lot of places inside the engine due to humidity and temperature changes, not just in the crankcase. That's why engines thus "stored" are often seized and unable to rotate.

Pairajays 09-25-2011 08:59 AM

Quote:

Originally Posted by Full.Monte (Post 967168)
Jim,

This is from Wikipedia:

Air ventilation

Main article: crankcase ventilation system
During normal operation, a small amount of unburned fuel and exhaust gases escape around the piston rings and enter the crankcase, referred to as "blow-by".[7] If these gases had no controlled escape mechanism, the gasketed joints would leak (as they "found their own way out"); also, if the gases remained in the crankcase and condensed, the oil would become diluted and chemically degraded over time, decreasing its ability to lubricate. Condensed water would also cause parts of the engine to rust.[8] To counter this, a crankcase ventilation system exists. In all modern vehicles, this consists of a channel to expel the gases out of the crankcase, through an oil-separating baffle, to the PCV valve, into the intake manifold. In a non-turbo engine, the intake manifold is at a lower pressure than the crankcase, providing the suction to keep the ventilation system going. A turbo engine usually has a check valve somewhere in the tubing to avoid pressurizing the crankcase when the turbo produces boost.
If an engine is damaged or enters old age, gaps can form between the cylinder walls and pistons, resulting in larger amounts of blow-by than the crankcase ventilation system can handle. The gaps cause power loss, and ultimately mean that the engine needs to be rebuilt or replaced.[7] Symptoms of excessive blow-by include oil being pushed up into the air filter, out the dipstick,[9] or out the PCV valve. In rare cases of serious piston or ring damage, the oil filter housing's sheet metal can even burst at its seam.
------------------------------------------------



So, the crankcase is not sealed. Therefore, condensation inside the crankcase can deposit water into the oil and start corroding the oil pan.
If you've ever seen an old car or truck sitting out in a farmer's field for a number of years, you might successfully wager that rust has formed in a lot of places inside the engine due to humidity and temperature changes, not just in the crankcase. That's why engines thus "stored" are often seized and unable to rotate.

The Wikipedia article is referring to an engine that is running, not stopped. Very little, if any, air exchange can take place through the crank case ventilation system when the engine is not running. "Old" cars and trucks had a much different ventilation system. I agree that internal engine components can get rusty after sitting for "years" but I don't think it is going to happen in 5 or 6 months, which is what this thread is about.

Jim E

Poptop 09-25-2011 08:20 PM

The odds of finding many motorhomes that have been driven 15,000 miles a year are better that me winning the lottery, but not very much better. The MH that has had religionous maintenance is probably going to be a safer bet. Having said that when reading the comments posted here consider your risk tolenance. Some people wear suspenders with belts to be safe, others are willing to be more adventureous. If the scheduled maintenance is specified to be three years and it doesn't get done until four years or so it probably won't be an issue unless you have a claim you want covered under warranty.

HD4Mark 09-26-2011 07:28 AM

Let's face it, anytime you purchase something pre-owned, commonly known as used, it is a crap shoot. High miles means the engine got lots of use. Might be better for the engine but perhaps not for everything else. Our '04 is the first used vehicle I have owned in about 30 years. Made me nervous but other than a few fixable problems it has worked out fine.

I will say that even if we may have paid a little more buying from an RV dealer, we were treated very well. A couple of problems with it were taken care of no questions asked. We were also able to trade in the old MH. Again we may have been able to get more for it or save some money with a "clean deal" but it not only saved the problems with selling it but saved 8.25% tax on the trade in amount that was taken off the purchase price. Just some of the differences between a dealer and private sale.

The dealer was Colton RV in Buffalo NY if anyone is interested. YMMV

DA_BUS 09-27-2011 08:14 PM

We are on our second diesel pusher and been around trucks all my life - still have 5 tractor trailers in our fleet.....engines that are made to run over a half a million miles before any work on them needs to be performed are going to survive a lot longer than the everyday issues the other parts of the coach will bring up. Make sure the coach drive train has been mantained regularly and focus more on the rest of the coach. Cummins and Allison (and the other brands) are made for the long haul and are built to take it - these manufacturers are not slouches....if the motor and transmission has been developed in over the road tractors that pull 80,000 pounds day in and day out - the drive train would be the last of my concerns. Make sure the drive train has some consistent activity - not high mileage - but started and used enough on a regular basis to keep things lubed and in working condition....you are never going to be able to second guess if you have bought a "bad" driveline until it happens or previous service records reveal it....so "buy one" and enjoy!

RVNeophytes2 10-02-2011 08:11 PM

Chemical Aspect of Oil Change Interval
 
Quote:

Originally Posted by Pairajays (Post 963117)

Annual oil changes, without substantial milage, is not required, IMO.

Is this true in diesels? As an airplane mechanic, I stress annual oil changes as the very least; six months is often preferable. The reason is that your oil protects in two ways: mechanically, by definition; and, chemically by maintaining a protective coating on surfaces inside your engine. With the introduction of moisture, acids form, the protective role is compromised, and engine life is shortened.

Cummins, in their bulletin entitled CumminsŪ Engine Oil and Oil Analysis Recommendations, says the same thing: Oil provides a protective barrier, isolating non-like metals to prevent corrosion. Corrosion, like wear, results in the removal of metal from engine parts. Corrosion works like a slow acting wear mechanism. These are the engineers who built your engines, who gain nothing if you shorten your oil change interval. But, they don't quantify the amount of wear nor do they address environmental variables.

Now, in jumps the State of California, which says you can optimize wear by using premium oil and high efficiency filters, coupled with extended change intervals. Their findings are HERE. Does the same thing apply in Ohio, Florida or Michigan? I have no idea.

What do our professional diesel mechanics think?

phredsee 10-03-2011 12:03 AM

Mike...
We found a specific model motor home we were looking for but it had 10,000 on the motor with 410 hours on the generator, go figure. No service records as this was a bank repo bought by the dealer at a lower price. We also realized that tires would have to be replaced and all systems tested, including liquid analysis, outside Cat dealer verified the motor, including the Alison transmission. No service codes and some work done to brackets for safety underneath.
We set aside about $10,000 for any repairs we might have that didn't show at time of purchase, excluding tires and shocks.

After we purchased, we had all fluids replaced on the engine, transmission and radiator. Most hoses replaced. We had no service records so I felt we needed a starting point for current usage and future service requirements.

Things that have already gone wrong were (2) coach batteries needed replacing, roof sealant brokedown on trip with entire left side lifting up but luckily repaired, (2) leaking windows I corrected and some other minor problems that were easily fixed. The jacks need to be serviced and plan on doing that shortly.

Bottom line is depending on how far back in years you go and as others have said, buying used is an unknown factor unless you have reputable service records, plan on spending some bucks along the way.

So far we are happy with our decision on buying a higher end coach and with continuing preventive maintenance, we have expectations it will last a long time.

Good luck in your search and get what you want but practice the caveat emptor thing.


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