Not running Diesel engines for extended periods

[Skip426]

Originally Posted by castrol

I would imagine the "cool down" is more for the turbo, not necessarily for the diesel engine.

Turbo, exhaust manifold , valves , pistons, all are at max temps after a long climb; and best to be cooled off before shut down.
One of the less than 2 dozen Dodge Cummins engines I replaced in 14 years, of working on them, was due to multiple pistons , scuffing the cylinder walls when the owner shut the truck off hot at a summit view point, after an 11 mile climb , pulling a 5er. High temps boiled the oil off the rings.

[Papa_Jim]

Originally Posted by georgetown350

The alternators on these coaches are not meant to replenish
almost dead house batteries as when dry camping ( not using genny)
House batteries should be brought up to charge by shore or gen
power then handed over to the alternator for the trip. Otherwise they wont
last.

Jim

[jeanbev]

I have owned diesel powered boats and MH since 1989 and whenever I let the engine set for 6 months or more invariably I incurred operating problems with costly repairs. The last occasion occurred in Virginia when MH was in storage outside for the summer and alternator had seized which resulted in a 75 miles tow plus a new alternator. Since then I store my wheels close to home where I can run it up to operating temp and drive at least 25 miles.

[jim.smithjr]

When I started my motor home last spring in Victoria I was greeted by the "Alt Fail" light and a repair bill for a replacement.

It was always my habit to start our Cummins on the first of each month, set the "Cruise" on and run the engine at fast idle for 20-30 minutes.

Last winter my farmer neighbour talked me out of that. Mistake. I'll be back to my monthly run-ups. When we are parked for the winter, going for a drive is tough to do. I know that would be even better.

In salt air, rust is also a threat, and that's what did in my alternator.

[ShapeShifter]

Originally Posted by Larry Geese

more harm is done by sitting and running the engine and shutting it off. Chemicals and acids don't burn off with out being at operating temp. The brakes, air, transmission etc all get exercised as well....good for all. DRIVE THE THING!!

That's an easy thing for a Californian to say. Some of us wish we could just drive the thing over the winter.

There isn't much snow yet in this picture, as it was still early in the season. By mid-winter the snow is usually several feet deep drifted across the trailer. It's a significant effort to dig out the motorhome: (especially between the coach and the barn where there isn't anywhere to put the snow!)

And if I did get it dug out, there's the issue of getting back up the driveway after "just driving the thing." It's a gravel driveway which is almost impossible to scrape completely clean without plowing all of the gravel away. This was a shot from the last time I tried to get up the driveway in winter:

It doesn't look it, but the foreground of the picture is a significant slope, then after the turn it's a quite steep slope to the top. I made it about 10 feet further than shown, then slid back (even with the brakes on.) The front wheel had slipped off the left side of the driveway, so I couldn't steer while backing down. By the time I got the front wheels back on the driveway so I could steer, the back corner was into the fence off the right side of the driveway. I needed a neighbor with a huge tractor to come over and pull it back onto the driveway, and I needed some repairs to the fence and the back right corner of the coach.

So yes, the best thing to do is take it out periodically and drive it. There's no question about it. But if you can't drive it, then what? That's the point to this thread. Personally, I'm not risking it again by taking the coach out over the winter, I'm just going to let it sit. I'll exercise the generator under load, but the coach engine will sleep peacefully until spring.

[walt2137]

Originally Posted by doublechevy

I am beginning to question the commonly stated fact that you should not start your diesel if you are not going to move it for a long period of time.
I just started my coach after it had been sitting for about 6 months. Only to find that the alternator had seized and resulted a broken serpentine belt. I wonder if this could have been avoided by starting the coach and putting a load on the alternator ( as I do for the generator) I believe that the bearings seized due to moisture and the climate in Florida. Would it not have been better to start occasionally. Luckily I started a week before we are scheduled to leave. That also brings up the question on extended warranty which I have with AMG they say they will pay only $492.00 of a $776.00 cost to replace on site.

I would have the alternator rebuilt, no reason to replace with new.

[kketterling]

One thing that hasn't been mentioned here is that idling newer diesel engines with DPF systems can cause more problems then solved.

My approach is if I can't take it out for a drive of 20 minutes or more I don't run the engine. We usually use the coach about every other month so normally it sits the rest of the time.

[Vacay Wheels]

Here is what North Dakota does with their snow plows over the summer:

All rotary snow plows should be exercised once every 60 days. Exercising should consist of slow and fast idle for about five minutes and the balance of an hour driving on the road. Enter one hour on the vehicle use report and submit.

Seems like pretty sound advice.

[Neverhome2]

There is a lot of old engine practices in vogue today but is not entirely relevant to modern diesel engines. I have owned diesel class 8 trucks from 1970 until I retired in 2012. From a 220 hp Cummins to a 600 Cummins . The last engine used DEF and had a particulate trap. My point is when E-motors were introduced the operating parameters of diesel engines changed radically.

Mechanically operated injectors spit fuel and washed cylinder walls at idle. Mechanical timing changed with wear on the chains and gears. This caused ignition problems with pre-detonation and hot spots and fuel mixing with the crankcase oil that destroyed idling engines.

When the computer controls piezo-electric injectors and sets the timing from a real time clock fuel build up while idling is nearly eliminated. How ever when cold and fuel is not all burned there is still some issue at slow idle. The software has just about eliminated it all though. The best thing to do is start the engine monthly, after oil pressure is up turn on cruise control set the idle to 1200 rpm. This will allow the engine to reach operating temperature in a short while. Then raise the rpm to 1500 simulating a load this will raise the temps to a loaded range. let run for half an hour to bring transmission and all sytems to operating temps. After the half hour turn of cruise and allow the engine to just start to cool at low idle, then turn it off.

[RodgerS]

I was gonna suggest a modification to turn the rig into a snow plow, but...

[RodgerS]

This has been a great thread for me because I will soon be in the market for a dp. I can partially qualify my dp mechanic who will be doing the review of the used coach by asking him his understanding of the proper procedures when storing a dp.

I can also ask the owner what procedures he followed and then inform the mechanic before the review begins. I can also include that in my negotiations.

Good examples, with all due respect, of experience in using a dp vs a mechanic's expertise. One particular experienced users procedures doesn't always make for good advice and mechanical expertise can vary.