Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: WaltH on July 20, 2014, 12:27:15 am
Title: Cummins lifespan
Post by: WaltH on July 20, 2014, 12:27:15 am
I've been looking at the various ads for Foretravel coaches at MOT, FOT, and around the internet, and I have been noting the mileage on the various coaches. All of that got me to wondering about something. Assuming all routine maintenance is done in a timely manner, how long in terms of number of miles should a Cummins engine last? is it much different for other diesel engines? Thanks.
Title: Re: Cummins lifespan
Post by: Pierce & Gaylie Stewart on July 20, 2014, 12:38:16 am
Without overheating and with proper driving technique, it should outlast several owners. Would think 500K would not be unreasonable. I met a guy with just a 6.9 Ford diesel PU that traded it in with 612K with only oil changes. He pulled the very long horse trailers everyday with it. My 300SD has over 440K with nothing done to it, only a couple of valve adjustments.
Pierce
Title: Re: Cummins lifespan
Post by: propman on July 20, 2014, 12:46:51 am
A friend of mine has a 2004 Dodge Cummins (5.9) Just rolled 500K. He purchased it used with 160K on it. Nothing done to engine, just routine oil change & valve adj. I hope I can get the same out of my 06 Dodge Cummins, 89Kmil & U225 68Kmil so far so good.
Title: Re: Cummins lifespan
Post by: WaltH on July 20, 2014, 12:50:32 am
Do you think it would be safe to expect something close to the same number of miles from a Cummins engine in an FT coach?
Title: Re: Cummins lifespan
Post by: propman on July 20, 2014, 12:56:00 am
I do.
Title: Re: Cummins lifespan
Post by: amos.harrison on July 20, 2014, 07:07:40 am
I think engine longevity is related as much to usage as to maintenance. If you use your coach every day for several hours you should expect million mile life. If you only use it a couple weeks a year without monthly use, 200K miles might be a lot. Full-timers with monthly usage-probably 500K would be reasonable. In any case, quite a range in expected outcomes. It makes you think about newbies thrilled to find a very low mileage older coach!
Title: Re: Cummins lifespan
Post by: John S on July 20, 2014, 07:35:31 am
I saw a FT a coupke years ago with 470k on it. Talking with a couple techs they said they saw some coaches with 600 and 900k. I am not worried about longevity and longer of the engine. I am at 162 and running strong.
Title: Re: Cummins lifespan
Post by: Chuck Pearson on July 20, 2014, 07:51:01 am
Can't recall ever seeing a post here like "Well shucks, I finally wore out my Coach!" Unfortunately, however, the same thing is not true for the owners.
Title: Re: Cummins lifespan
Post by: Chuck & Jeannie on July 20, 2014, 08:05:11 am
163,415 on my '93 U280, and zero troubles associated with the Cummins long block or the Allison. Judging by Forum posts, it appears that the external accessories added by the coach builder tend to wear out long before the basic engine/transmission. Perhaps we need a "sticky" thread where we can keep track of the highest mileage coach owned by a Forum member. Might be interesting to know "who holds the record".
Title: Re: Cummins lifespan
Post by: pocketchange on July 20, 2014, 10:40:59 am
01' 5.9L in my 1Ton DODGE finally sealed up (broke-in) and quit needing oil @ 260K. I'm now just shy of 400K and have typically pulled 10/15K loaded on a 40' gooseneck w/tar of 19K. That is 34/36,000 lbs. It runs better now than it did when it was new.. (believe it or not.) Simply put, its out lasted me (the rig is looking for a new home btw.) Note; after 5 NV (transmissions) I replaced it with a FS6406 Road Ranger 6 spd OD and never looked back. I had the M series in my Class 8 (big truck) @ 80K which I sold w/600k miles and it never missed a beat. pc
Don't abuse them and they will run long after you are tired of driving it.
Title: Re: Cummins lifespan
Post by: drcscruggs on July 20, 2014, 11:01:42 am
I have a 2002 Ford 7.3 turbo diesel that has 250K on it and it really runs just fine. I would not have any concern about taking off on a 1000 mile trip right now with it, as I have had nary a hiccup with it since purchase new. I changed the water pump @ 140K and it may be time to do it again soon. My understanding is that you never want to drive a diesel hot. That is a killer. Yes, I agree with the others on routine oil changes and other PM. I would expect 500K to be expected with just routine maintenance. I would not be wanting to buy one with 500K on it, but would not be too hesitant on one with 100+k on it. My FT has less miles than my truck. I used the truck as my example as it is a very good diesel engine though different from the cummins. If you don't feel confident in your ability to "check it out", then enlist the services of someone who may be able to assist in that determination. I would also look over the other aspects of the coach in my perusal of the right one.
Title: Re: Cummins lifespan
Post by: Michael & Jackie on July 20, 2014, 11:18:05 am
For whatever it is worth, a very knowledgeable in the business said when buying I should be much more concerned for low mileage rather than high on the engine, that the mileage should be appropriate to the age. In other words, what sounds like few miles would be ok for a newer coach than the same mileage on an older coach.
I hesitate to give you the example of miles per year he saw as too few for a ten year old coach I was considering. I think he would tell you that if there was maintenance done and mileage seems too low, if mileage was due to frequent use rather than only a few long trips, that might change your view. I bought a ten year old with 135,000 miles over one with 62,000 miles due to analysis of the total coach package.
At some point other things are more important than engine mileage/age
Mike
Title: Re: Cummins lifespan
Post by: Neal Pillsbury on July 20, 2014, 12:10:20 pm
I think engine longevity is related as much to usage as to maintenance. If you use your coach every day for several hours you should expect million mile life. If you only use it a couple weeks a year without monthly use, 200K miles might be a lot. Full-timers with monthly usage-probably 500K would be reasonable. In any case, quite a range in expected outcomes. It makes you think about newbies thrilled to find a very low mileage older coach!
Brett, I have to ask a curiosity question. Do you have any basis for feeling that way? I have to ask because it must be scary for a newbie to think that a motor-coach diesel may be beyond its useful lifetime at 200K miles. From years of nuclear submarine service and nuclear power plant operation, where diesels generally sit idle for months on end, the exact opposite is true. Proper maintenance and operation is invariably the key to longevity, not the duration or accumulated total of idle periods. Now in general, the Navy and civilian nuclear power plants have much more complex and sophisticated testing and maintenance routines than municipalities and owners that contract emergency standby unit service companies, but I don't recall ever seeing or hearing of early failures (where the diesel engine has been properly maintained and tested). I have seen cases where the test criteria lead to early failures, but the criteria was unrealistic for any engine. Once the criteria was made realistic, no more failures. The navy and civilian nuclear power industry generally expect at least 40 year lifetimes, often far more, and the diesel units (ranging in size from small fire system priming and standby diesels, to multi-megawatt Engineered Safety Systems Generators) often run for only 12 to 24 hours, once a year or once every six months. At the same time, the Fairbanks-Morse (and the Colt-Pielstick PC 2.3, 6,083 kW (6 Million Watt) that I'm most familiar with), are routinely passed into peaking power service applications and they contribute decades of full time service following decades of emergency standby service. So my experience (based on operating and interpreting diagnostic equipment on large and small diesels over a lot of years) is that if you maintain it properly and operate it realistically, in accordance with the manufacturer guidance, down time vs. run time is all but meaningless. But, if you abuse maintenance, operate recklessly and don't follow manufacturer guidance, you can break any diesel, without exception. Neal
Title: Re: Cummins lifespan
Post by: Caflashbob on July 20, 2014, 12:21:03 pm
Last I saw Cleo Dunlap his 300 cummins had 306,000 miles on it. Gave it to his daughter who I think is still driving it.
Title: Re: Cummins lifespan
Post by: Chuck Pearson on July 20, 2014, 01:22:04 pm
Neal makes an interesting point, and I tend to agree. It's hard to imagine an industrial duty diesel engine degrading because it sits without running. Granted, there are some exceptions such as rotating seals, tires and so forth but as long as it's covered and has oil in it, and minimal air circulating thru it, hard to see what there is to go wrong. For a gasoline engine there's probably some truth to it as the fuel system will be affected by aging gasoline. Diesel is viable for many years.
And as long as we're goring sacred oxen, the oft repeated advice to never start a diesel engine without bringing it up to operating temp? How many high mileage diesel pickups are around that are regularly cranked up, driven a mile or two and shut down. My 7.3 liter grocery getter has never complained and looks to be good for another 15 years 250K miles of use/abuse.
Title: Re: Cummins lifespan
Post by: Tim Fiedler on July 20, 2014, 01:39:54 pm
Unless you are 20 years old and plan to live to 100 mileage irrelevant
Nada does not use mileage on a DP as a factor in valuation
Regular service by owner only consideration
Title: Re: Cummins lifespan
Post by: Tim Fiedler on July 20, 2014, 01:40:47 pm
Yes, and more. With service per mfg
Title: Re: Cummins lifespan
Post by: Forewheelers on July 20, 2014, 03:01:53 pm
Never had a concern for mileage on a cummins engine. Service is the key. I have a number of grain haulers that run 3 months a year, sit the rest. The mileage on them run from 500,000 to 800,000 with one being a m 11 red top cummins with 1.3 million.
Title: Re: Cummins lifespan
Post by: Pierce & Gaylie Stewart on July 20, 2014, 06:43:16 pm
While oil changes, valve adjustments will keep the engine on target for a long life, other driver technique related procedures can make sure the engine takes advantage of the maintenance it gets.
I know I have mentioned it before but controlling turbo temperature is a good way to keep the mechanic away. Turning off the engine for a photo op at the top of a grade will not only shorten the life of the turbo but also have a direct impact on overall engine life. A hot turbo will start to refine the oil inside as there is no fresh oil to help cool it. The oil turns to coke and the turbo seals may be damaged. The damaged seals may allow engine oil to enter the intake system and cause the EGT (exhaust gas temperature) to spike and overheat the pistons, valves, etc. This can cause a failure in a short time or down the road a ways.
Allowing the engine to idle for long periods will also have a negative impact on engine life. Our DDEC computer can be programmed to automatically shut off the engine after 5 minutes of idle time. This was put there for a reason.
External components can also cause an early engine failure. In our case, the hydraulic pump to drive the radiator fan(s) is a so-so design poorly aligned by the factory when installed. A broken belt is always followed by overheating and even if the engine automatically shuts down, may still cause some damage.
At Quartzsite, one member had a new engine installed as the low mile original engine had damage in one cylinder. Other have had unfortunate stories about failures on the forum. None of our engines fail out of the blue. They are designed to operate for long periods of full throttle as long as the operating temperatures remain within design limits (both coolant and EGT) so they love hard use but not misuse.
While buying a used coach with more than 100,000 miles is no big deal, proper operation by the previous owner has a lot to do with the next 100K you drive it. Another reason to be able to retrieve stored fault codes for the reason, date, duration before handing over the cash. The "black box" is an advantage the electronic controlled engines have over the mechanical engines. Otherwise, having the right questions to ask the seller can tell a lot about how they took care of the coach.
My two cents for a Sunday afternoon.
Pierce
Title: Re: Cummins lifespan
Post by: TAS69 on July 20, 2014, 08:16:59 pm
While oil changes, valve adjustments will keep the engine on target for a long life, other driver technique related procedures can make sure the engine takes advantage of the maintenance it gets.
I know I have mentioned it before but controlling turbo temperature is a good way to keep the mechanic away. Turning off the engine for a photo op at the top of a grade will not only shorten the life of the turbo but also have a direct impact on overall engine life. A hot turbo will start to refine the oil inside as there is no fresh oil to help cool it. The oil turns to coke and the turbo seals may be damaged. The damaged seals may allow engine oil to enter the intake system and cause the EGT (exhaust gas temperature) to spike and overheat the pistons, valves, etc. This can cause a failure in a short time or down the road a ways.
Allowing the engine to idle for long periods will also have a negative impact on engine life. Our DDEC computer can be programmed to automatically shut off the engine after 5 minutes of idle time. This was put there for a reason.
External components can also cause an early engine failure. In our case, the hydraulic pump to drive the radiator fan(s) is a so-so design poorly aligned by the factory when installed. A broken belt is always followed by overheating and even if the engine automatically shuts down, may still cause some damage.
At Quartzsite, one member had a new engine installed as the low mile original engine had damage in one cylinder. Other have had unfortunate stories about failures on the forum. None of our engines fail out of the blue. They are designed to operate for long periods of full throttle as long as the operating temperatures remain within design limits (both coolant and EGT) so they love hard use but not misuse.
While buying a used coach with more than 100,000 miles is no big deal, proper operation by the previous owner has a lot to do with the next 100K you drive it. Another reason to be able to retrieve stored fault codes for the reason, date, duration before handing over the cash. The "black box" is an advantage the electronic controlled engines have over the mechanical engines. Otherwise, having the right questions to ask the seller can tell a lot about how they took care of the coach.
My two cents for a Sunday afternoon.
Pierce
Thank You!
Title: Re: Cummins lifespan
Post by: WaltH on July 20, 2014, 09:29:17 pm
I've heard that too few miles can be more of a problem than too many. I don't know that I was worried about buying (eventually) a coach with "too many" miles on it, but it is still reassuring to have others chime in.
Although it wasn't an FT, someone mentioned putting several (five?) transmissions in their truck. That makes me think the transmission may be the weaker/weakest link. How long should one expect the transmissions in an FT to last, all things being equal and all regular maintenance having been done?
Title: Re: Cummins lifespan
Post by: Caflashbob on July 20, 2014, 09:45:53 pm
Not sure if its fair on either end do please do not think wrong of my comment but if were a buyer I might offer less for a "miler" if the seller made any allowance in the conversation about the miles.
All the systems have been worked more if the miles are higher.
My question always as a Foretravel sales manager viewing a lower than normal miles coach was "was it a live in?"
Soft floors in the hallway on the old coaches was the result and worn carpeting and furniture and appliances.
Too many or too few miles always made me ask more questions. Hated extra holes anywhere.
Will not let DW put a hole in our u320
Title: Re: Cummins lifespan
Post by: John & Genni on July 20, 2014, 10:25:35 pm
I have been driving and working on diesel & gas equipment for more than 40 years. When we came across our 97 U320 about 8 months ago it was still owned by the original owner and the Cummins M11 Redtop had 9300 miles on it. ( not a typo, 93 hundred miles) This coach was pristine inside and out. PO had many health problems and was never able to use this coach much. Never cooked in, fridge never used, interior looks brand new. The owner did start this coach and drive some every 1-2 weeks. I had this coach serviced and new tires installed before driving home to Texas from Knoxville (950 miles) with no mechanical issues. I have since driven another 3000 miles and have sent an oil sample to the lab. The lab shows no engine issues at this time. So far this has been a very nice coach and we consider ourselves lucky to be the current owners. The PO owns heavy equipment and knew that this U320 needed to be exercised and did not leave it sit . Every coach may not turn out this good, but this is my 2nd Foretravel and I began looking at them since the early 90's. Check out the details before making a decision on a low miles or a high miles coach. Information and knowledge together will help you make an informed decision.
Title: Re: Cummins lifespan
Post by: Pierce & Gaylie Stewart on July 20, 2014, 10:45:18 pm
I've heard that too few miles can be more of a problem than too many. I don't know that I was worried about buying (eventually) a coach with "too many" miles on it, but it is still reassuring to have others chime in.
Although it wasn't an FT, someone mentioned putting several (five?) transmissions in their truck. That makes me think the transmission may be the weaker/weakest link. How long should one expect the transmissions in an FT to last, all things being equal and all regular maintenance having been done?
Don't know the heritage of the later Allisons but our 4 speed HT746 was used in a lot of garbage trucks and buses. Can't think of a harder application than start and stop garbage trucks where torque converter slippage keeps the average internal temperature much higher. Foretravel RV applications are light duty and much lower temps with lockup on the highway.
I had a Getrag manual 5 speed behind the 7.3 and while they all growled in first gear, they were reliable. Think they are made in Germany. Dodge PUs had a lot of both automatic and manual transmission problems. Thought they used two different manual transmissions with one giving a lot more problems than the other.
Pierce
Title: Re: Cummins lifespan
Post by: wa_desert_rat on July 21, 2014, 01:38:59 am
I bought a 1994 Dodge 3/4 ton diesel in 1996 with 30,000 miles on it. It became the farm truck and anyone who had a job on the farm basically drove this truck. Sat during the winter but was used a lot during the summer. Anything from refueling tractors to hauling ladders to the orchard to trips to toen (35 miles each way) for parts, seed, fertilizer, etc.
It has 250,000 miles on it (more-or-less) and still starts right up first click and gets 21mpg. Injector pump went out on it about ten years ago and as far as I can remember that's been the extent of repairs.
These things are remarkably durable!
Craig
Title: Re: Cummins lifespan
Post by: WaltH on July 21, 2014, 09:06:10 am
Thanks for all of the insight and information. While I suppose it is possible to become overloaded with information, I'd rather have more than less. I've never been accused of knowing too much. :D