Not running Diesel engines for extended periods

[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.

[96 Wideglide]

No doubt.
I dont go more than about 5 weeks without running mine, even if there's snow or salt on the roads, and I dont plan on going for a drive.

[2500HD]

I don't own a diesel motorhome, but I have owned various pickups and heavy diesel trucks. With that being said most any engine that is sitting for long periods of time can benefit from being run up to temperature once a month or so. Set the motor at a high idle and let it run for a 1/2hr or so. Where guys get the idea "if you can't run it let it sit" is a mystery to me. The motor will still warm up at high idle, and does not need to be put under a load to be beneficial.

If anything I would be worried about a "DRY START" after sitting for six months.

[jmoffat]

2500HD what you say makes sense but there are a lot of threads that say not good to idle a deisel it cokes the oil (?) the wisdom given is to turn the motor on let the air and oil pressure build up and then slowly leave the CG or wherever you are and then run it as required

Jim

[1skier]

I am not a diesel mechanic, and do not even play one on TV, however, I was a Machinist Mate in the USN for 11 years. One of my responsibilities was the sub's diesel generator on several different boats I spent time on (Fairbanks Morse 38ND8 1/8 6 cylinder, opposed piston design for the most part - monster compared to my ISC330). I do recall that the biggest problem with running a diesel for short periods of time was mostly because until the engine gets up to normal operating temp, all the engine components are "slightly sloppy" - things like rings and valves don't seat well until up to operating temps (maybe why a cold engine is noisier than a warm one?) This allows fuel to wash the cylinders to a certain extent, and get into the oil pan. You can prove this action by taking a few oil samples - you will notice higher levels of fuel in the oil on engines that run short periods of time. I always run my engine to normal operating temp if I have to start it, and I try to load it for some period of time to cook off any fuel that may be in the oil. And even if it is put up for the season, I start it at least once a month and drive it for 20 or 30 miles to keep everything working as designed.

[calhyatt]

Diesel engines do not need to idle more than a few minutes to warm up. In fact extended idling causes engine damage. Engine manufacturers generally recommend no more than three to five minutes of idling. Caterpillar Inc. cautions drivers to "... Avoid excess idling. If the vehicle is parked for more than five minutes, stop the engine. Excessive idling can cause carbon buildup and/or excessive idling can cause the engine to slobber. This is harmful to the engine." IC Corporation’s engine manual states that "...Excessive idling reduces fuel economy, and may decrease oil life."

[Steve N Sal]

Our neighbor here in the park says his coach goes nowhere unless he gets paid to move it. ????? Have to wonder, why do you own a coach at all. Surely doesn't make any financial sense to me. 4 years old and only 14K miles. And to boot only 1 oil change. Surely not a coach I would want to end up with.

[doublechevy]

After seeing the responses to the thread I will not let my coach sit anymore for 6 Mos without being started.

thank you for all your input. The repair company said they will have repaired by tomorrow. I then can finish preparations to head back north to NY early next week. Last year when I was about to leave I started the coach and got a warning of no oil pressure it ended up the oil sending was bad.( again after sitting 6 Mos) without being started. this should have been a sign of things to come. will not happen again

[jamesrxx951]

That alternator has sealed bearings. They are a lube for life bearing. If the seals are in good condition then there is no reason that the alt should have failed like that because the lube is in the bearing. Many sealed bearings (aka wheel bearings, drive shaft carrier bearings) also do not move for long periods of time with no issues. If I was to take an educated guess at it, you likely saved yourself from being broke down on the side of the road from an alternator that seized and threw the belt on the highway.

However, it is best for the engine, transmission, hydraulic systems to get worked at full operating temps on a regular base.

[bgbranch]

I am a certified diesel mechanic and heavy truck and RV repair facility owner.
A diesel engine should be started periodically, but only if it is brought up to operating temp and then driven to load the engine, which burns off excess fuel in the cylinders and allows the oil to properly lubricate the cylinder walls before shutting down. It also dissipates condensation which forms while setting idle.

[jablair]

Originally Posted by bgbranch

I am a certified diesel mechanic and heavy truck and RV repair facility owner.
A diesel engine should be started periodically, but only if it is brought up to operating temp and then driven to load the engine, which burns off excess fuel in the cylinders and allows the oil to properly lubricate the cylinder walls before shutting down. It also dissipates condensation which forms while setting idle.

what he said!! The main point is you must let the engine reach full operating temperature. Place a load on the engine is even better.

[Tony Lee]

Not just the engine - what about tyres and running gear, oil bath wheel bearings etc.

What some do suggest is that if you can't drive it to a warmed up condition then you might as well let it sit..

My vehicles sit until we pick them up - and that means they can sit there for up to two years. Nothing I can do about it and I don't worry about it either. So far, so good.

[2500HD]

Originally Posted by jmoffat

2500HD what you say makes sense but there are a lot of threads that say not good to idle a deisel it cokes the oil (?) the wisdom given is to turn the motor on let the air and oil pressure build up and then slowly leave the CG or wherever you are and then run it as required

Jim

That's why I said HIGH Idle which keeps the oil pressure up and allows it to warm up faster. If its cold out I like to increase the throttle as it begins to warm. Say from 900 rpm to about 1500. This should solve the problem with cylinder washdown or fuel issues.
I have a friend with a 550 cat in a peterbuilt and whenever he lets his truck idle for more than a min he brings it up to about 1,000rpm to keep oil pressure up.

[Triker56]

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.

Wow!! I replaced a alternator on my Cummins engine myself for under $200

Ask any farmer if they start any of their diesel powered tractors/combines to warm up if setting for over a month. Some of them are only used a few weeks a year.

I have had no problem letting my DP sit for 6 months a year for the last 12 years without starting it to warm up. Parked it September 20th 2013 and I did start it up April 7th 2014(6 months 18 days) to change filters/fluid in the Allison transmission.

Needed to get the transmission fluid up above 140º before drain and check refill level from Pad. Otherwise it would have sat until April 26th weekend before leaving on summer trip. Usually have to add some freon for the dash AC.