What causes motorhome engine failure/rebuild?

[aztec7fan]

Last year we were looking for a motorhome on Craigslist and other sources. We finally purchased a 33-foot 1989 Southwind, which we are really happy with. While we were looking, I noticed that many of the motorhomes for sale had rebuilt engines in the 60,000 to 80,000 mile range. This seems low considering these are heavyduty truck engines. I was wondering if there is an underlying reason why some motorhome engines need to be rebuilt so soon?

Are the engines underpowered?

Is it due to poor maintenance?

Is it due to the fact that they sit idle for long periods of time?

Are they just not built as well as car engines?

I have a personal interest since our Southwind (gas Chevy 454) engine is at 79,000 miles and I would like to prevent any failures if at all possible.

Thanks,

Chris Guenther

f3508-s

[dalltop]

I have been asking myself the same question. I have always run well into the 150 - 230k range with autos. The Tahoe had 265,000 miles on the original motor. The boy that bought it is still driving it with over 300,000.

One big difference I see is that at 55 mph my Ford 460 (7.5L) is taching at around 2200 rpm which is its max torque. My Yukon at 55 is only taching at about 1600-1700 range. Over 80,000 miles the Ford will turn a lot more revolutions over its life.

Of course the weight and wind cause these units to under a constant load were the cars and trucks are not as heavy.

I hope some of it is lack of proper maintenance. If that is part of the problem then I should be ok because I am very careful to keep up with the scheduled PM.

[tbutler]

I think the lack of use issue is a serious consideration. Also, keep in mind that most maintenance recommendations have a time as well as mileage criterion. If you've only driven 10,000 miles, it is hard to justify performing the 2 year/60,000 mile maintenance and so you figure you can get by without doing the required maintenance. Given the choice, most people will focus on the mileage amount and ignore the time criterion.

Sitting idle is as bad for an engine as it is for a person. Recently there was news that sitting was deadly for humans. Sitting - no matter what you are doing shortens your life. I guess engines are the same... Better get mine rolling, we've been sitting for almost six months now!

Keep in mind the trucker that gets 2,000,000 miles from his big rig may do it in 3 or 4 years. Perhaps 3 or 4 years is the true life of the engine, not 2,000,000 miles!

[rossboyer]

Falure to maintain the engine per the manufacturer's specifications, using off brand filters, and not using quality lubrication products are the primary reasons that I have seen.

[kk5xy@wcc.net]

From experience in the older days with gasoline engines where they were underpowered or lets say they were close to maxed out with empty rigs. Then there were heat issues which is a big killer of engine longevity. Usually cracked exhaust manifolds were common along with quickly failing spark plug wires.

Granted the newer fuel injected engines of today are much better but again I would guess by the time a motorhome is loaded and ready for travel it is way maxed out. Then like previously stated are the RPM'S the engines are turning with the 4:56 gearing in the differentials, which it needed to get the thing moving down the road. So with all this said it is understandable why they need careful inspection in the 60K range even with good maintenance.

Good luck in buying many good older motorhomes with low mileage. Lack of use is just as harmful to all the components as well...Just find a good trustworthy mechanic if one is available to go over the mechanicals before spending a dime.

[Guest 2driftrs]

There's two main reasons for the rebuild sooner than expected - - wear and tear, and lack of use.

As mentioned by dalltop, RV engines are turning much higher rpm's. Our Ford V-10 runs 2600 at 55 mph, versus my Pontiac loafing along at 1450 rpm. Almost twice the rpm means twice the wear if it were directly proportional, which it's not (it's worse!). But then my Pontiac is only 3,000 pounds versus 18,000 pounds. And, contrary to what some RV dealers might tell you, the gas engines they put in motorhomes are the same as they put in cars and pick-ups.

The high rpm's these gas engines need to crank to get the rig down the road takes its' toll on engine life. One of the reasons Jan and I rarely take the Interstates. Going 55 instead of 70 means lots less wear and tear, longer engine life and much better miles per gallon.

The other thing is lack of use. A gasoline engine left idle for long periods can develop a fine oxide coating (rust) on the cylinder walls, valve stems, valve seats, etc. Then, start the thing up and the piston rings are scraping the rust off the cylinder walls, etc. Left for long periods, the oil drains off bearing surfaces, timing gears, etc. Get the picture? Before you know it you're in for a ring job, a valve job or a major overhaul.

At least once a week when we're not on the road, we start the rig up, drive it around the drive or down the road to let it get up to temperature. We had over 100,000 miles on our '88 Escaper, and all it had was a Chevy 350. It was still going strong when we sold it.

Here's a little tip you might find useful to minimize wear and tear - - use your cruise control on level highways, but leave it off if you're doing any hill climbing. The cruise control will try to maintain the set speed regardless of what gear it has to drop into. So if you're doing 55 up a hill, the cruise will shift you down one or two notches until your rpm's are through the roof! If you leave the cruise off and drop a few mph, you might be able to hold the higher gears and keep the engine revs down to something below the hearing threshold for pain.

[rdschoepf@gmail.com]

For what it is worth: The SAE has a B rating which is a predictor of engine life. The B rating is expressed in engine hours. A sales engineer from Perkins engines explained to me that variations in individual engine life could usually be explained by the amount of fuel consumed. Thus, a lightly loaded engine which uses less fuel per metered hour will last well beyond the B rating. Conversely, engines operated under heavy load (thus using a lot more fuel per metered hour) will fail to reach the rated hours. His explanation was basically that the more fuel you put through an engine per metered hour the sooner the engine will wear out - maintenance, cooling and other variables being the same in all cases. If this is correct then it becomes much easier to understand identical engines used in cars and motorhomes having much different life spans. Add the other factors already well stated in this forum and we probably have the answers.

[lt1093]

Ford Triton V10 Catastrophic Engine(s) failures;

 

I purchased a Tiffin 2014 Allegro 36LA a year ago this past February with 67,000 miles. I was told that the previous owner had to have the engine replaced with 21,000 mile because the engine seized up and was replaced under warranty at no charge. And’ several weeks out of service. Recently, I had the V10 triton engine tuned with new spark plugs and a full synthetic oil changed at around 70,000 miles. While working on a intermittent AC problem on the dash, I started the engine only to experience a noise from the engine. I made arrangements to take the motorhome to the closest authorized Fort truck motorhome service center. They directly examined the engine and informed me the the noice appeared to be coming from the top of the engine, the warranty company authorized $3,500 for repairs. This was executed without delay only to discover that additional noise/problems were coming from the bottom of the engine.  This would be three engines in less then five years. I am now a believer that the Ford Triton V10 is a poorly manufactured engine with numerous quality of steel faults. If one goes out on the internet you will find numerous V10 Catastrophic Engine Failures. 

 

Captain,

lt1093@aol.com

Ford Triton V10 Catastrophic Engine(s) failures;

 

I purchased a Tiffin 2014 Allegro 36LA a year ago this past February with 67,000 miles. I was told that the previous owner had to have the engine replaced with 21,000 mile because the engine seized up and was replaced under warranty at no charge. And’ several weeks out of service. Recently, I had the V10 triton engine tuned with new spark plugs and a full synthetic oil changed at around 70,000 miles. While working on a intermittent AC problem on the dash, I started the engine only to experience a noise from the engine. I made arrangements to take the motorhome to the closest authorized Fort truck motorhome service center. They directly examined the engine and informed me the the noice appeared to be coming from the top of the engine, the warranty company authorized $3,500 for repairs. This was executed without delay only to discover that additional noise/problems were coming from the bottom of the engine.  This would be three engines in less then five years. I am now a believer that the Ford Triton V10 is a poorly manufactured engine with numerous quality of steel faults. If one goes out on the internet you will find numerous V10 Catastrophic Engine Failures. 

 

Captain,

lt1093@aol.com

[dickandlois]

Chris, We had a 1988 coach on a P-30 Chassis with a 454 engine. We put 120,000 miles on the unit with no failures. It was traded in on our first Diesel Class A Coach, that allowed us to get 4 to 6 more miles per gallon. Interestingly the price for Diesel was 0.80 cents less then Gasoline at the time.  

The key was constant maintenance. plus 2 updates. Replaced the oil pump, because the lifters would click when it  was idling after it had been running down the road and everything was hot. The replaced oil pump idle pressure was increased to 70 psi. when idling hot. Also installed a large oil cooler and always used a 2 quart oil filters.

The oil ans filer was changed every winter so there was no contaminated oil in the engine over the winter when it was parked for 3 to 4 months. regardless of the mileage on the oil.

The gas tank was always topped off before it went into storage. 

One of the hardest items to keep in good condition was the 4 barrel carburetor. Always put some high quality carburetor cleaner / Top oil  in the tank before storing.  When the roads and weather allowed, it was driven for 20 to 30 miles every month.  

Rich.  

[wildebill308]

DickandLois, That is still good advise. 

lt1093, Welcome to the forum. That post/thread is almost 10 years old. I have never seen many people having catastrophic problems with the V-10. I think it is one of the most durable engines out there. You can't over rev it as it has a governor and is designed to be a hi revving engine. The onley detractor I can think of was the early engins with the short threads in the spark plug holes. That problem is easily repairable. 

Bill

[manholt]

The only problem I had with either engine, was warping of the right side manifold at the attachment point to engine!  A pre FI 454 caught fire once, foamed it down, Chevy replaced any item that was burned and could burn, got new manifold...Free!  Wife got new coach 2 weeks later, let me know by phone, the call cost was outrageous...I was in Columbia!

[kaypsmith]

On ‎8‎/‎2‎/‎2019 at 8:37 PM, lt1093 said:

purchased a Tiffin 2014 Allegro 36LA a year ago this past February with 67,000 miles. I was told that the previous owner had to have the engine replaced with 21,000 mile because the engine seized up and was replaced under warranty at no charge. And’ several weeks out of service. Recently, I had the V10 triton engine tuned with new spark plugs and a full synthetic oil changed at around 70,000 miles.

The only thing that I see wrong with this part of the story is! What type oil was the previous owner using and how often did he change it? Even at only 70,000 miles I would never go to full synthetic oil if I had no indication that synthetic had been used exclusively in the past. I'm a firm believer in synthetic oil, I use it in all of my automobiles and would in the coach if it had been used in the past, but it wasn't. Synthetic oil has a tendancy to clean the engine thoroughly and can cause break down of parts if cleaned too quickly. If you start your new engine out with full synthetic, I will bet a six pack that it will last a much longer life.

[jleamont]

I have seen many V10’s with over 300,000 miles in them. Every failure I saw when I was at the dealer were always related to improper maintenance. The biggest was too heavy of viscosity motor oil, low quality filters or not frequent enough oil changes. Believe it or not I saw many with 15w40 in them fail. Spec calls for 5w20 or 5w30 depending on the year and if 5w20 that spec is synthetic blended. The three valve engine will wipe the lobes off of the cams of idled too much. 

We traded our 1998 V10 in with 96,000 miles on it. Ran like new.

[wildebill308]

I have never had a problem switching to a quality synthetic regardless of mileage. Current coach started with 48,000 miles now around 98,000. My oil analysis reports look realey good.

I would run nothing but full synthetic in any Ford V-10 a 0w20 would be my choice and recommendation.

Bill

[rls7201]

I have personally experienced 3 cases of intake manifold leak on the 454 big block, that allowed coolant to penetrate a cylinder and cause hydrostatic lock.

If it were mine I would re torque the intake manifold bolts. If multiple bolts were loose I would think a new intake manifold gasket would be in order.

[dickandlois]

11 hours ago, RLS7201 said:

I have personally experienced 3 cases of intake manifold leak on the 454 big block, that allowed coolant to penetrate a cylinder and cause hydrostatic lock.

If it were mine I would re torque the intake manifold bolts. If multiple bolts were loose I would think a new intake manifold gasket would be in order.

Thanks for your feedback. 

Could you offer some mileage and driving conditions the 3 engines where exposed to that might have caused the intake manifold leak or if it was a material failure issue.

Rich.

[rls7201]

On 11/8/2019 at 11:40 PM, DickandLois said:

Thanks for your feedback. 

Could you offer some mileage and driving conditions the 3 engines where exposed to that might have caused the intake manifold leak or if it was a material failure issue.

Rich.

2 of then appeared to have loose intake manifold bolts due to gasket crush. The other one appeared to be from overheating and warped mating surfaces.

[aztec7fan]

FYI, my 1989 Chevy 454 p-30 has now gone 103,000.

[dickandlois]

6 hours ago, RLS7201 said:

2 of then appeared to have loose intake manifold bolts due to gasket crush. The other one appeared to be from overheating and warped mating surfaces.

The best solution for the exhaust manifold issues for us was to install stainless steel ones. A little on the pricey side, but never had another issue with them failing. All the way to Alaska, around Canada and out west a number of times. 

The cast-iron stile headers where very prone to cracking if the bolts where to tight and the gaskets failed when things where to loose. A catch 22 issue. The S.S. stile was a true once and done  deal for our Big Block.

Rich.