How often to start Diesel engine

[AJMike]

DW and I normally go somewhere every 3 weeks or so, so our RV does not sit long in storage and I have never had a problem starting it before. But the past couple of months have been unusually wet and cold (or what passes for cold here in southern Arizona) so we have stayed home.

However I went to start our RV last week and it started up, ran very roughly for about 1 second and then shut down. Started it again, same result. Again, same result. Finally it started, ran roughly for a minute or so and then smoothed out and acted normally after that, so I began to wonder if this was due to the fact that it had not been started for 5 or 6 weeks, or if it was the wet weather or the cold (probably not that. Cold here is 40F) or something else.

The RV is built on a Sprinter van and I wonder if the engine should be run every 3-4 weeks like diesel generators or if there is some other best-practice policy for a Diesel engines. Any suggestions?

[Cat320]

The answer to the question is never, unless you take the RV on the road and let all systems get up to operation temperatures. I had a diesel in a sailboat and it sat from Sep to Apr, and there are many instances of diesel tractors sitting for months without any problems starting.

[wolfe10]

Do NOT start a diesel engine unless you can drive 25+ highway miles.


While a diesel can reach operating temperature of the COOLANT without driving, it can not get the OIL up to high enough temperature to get rid of the moisture that is a normal byproduct of combustion.


Same for your diesel generator-- when running it for exercise, operate it on 50+% load for the same reason.

[pasdad1]

Maybe the diesel was starting to develop wax crystals from the cold? Have you treated the fuel with an anti-gel additive?

In cold weather climates the fuel is many times treated for winter season by the station you buy it from….however you may still have had summer fuel in the tank, or perhaps your local area never treats the fuel?

Do you have a block heater for your diesel? I always plug mine in overnight when temps drop below 45F and I want to start it the next morning. It really helps the diesel start easier, and warm oil flows to critical engine parts much quicker.

These are quick easy things to try to see if it improves the behavior you were seeing.

[AJMike]

Originally Posted by pasdad1

Maybe the diesel was starting to develop wax crystals from the cold? Have you treated the fuel with an anti-gel additive?

No. It rarely gets below 40 F here so I never thought it necessary. I guess I should look in Walmart and see if they even sell it.

Originally Posted by pasdad1

In cold weather climates the fuel is many times treated for winter season by the station you buy it from….however you may still have had summer fuel in the tank, or perhaps your local area never treats the fuel?

We travel frequently enough that there is always relatively new fuel in the tank, but I don't know if they treat the diesel fuel in this area. It rarely gets cold enough to worry about, although we do occasionally see temperatures at or slightly below freezing.

Originally Posted by pasdad1

Do you have a block heater for your diesel? I always plug mine in overnight when temps drop below 45F and I want to start it the next morning. It really helps the diesel start easier, and warm oil flows to critical engine parts much quicker.

These are quick easy things to try to see if it improves the behavior you were seeing.

I doubt that there is a block heater for the diesel. We bought it used, but only slightly used, and the people who had it before didn't do anything to it. The MB manual says nothing about a block heater and so I don't think MB installs one during the build and I have not added one. However it is something I guess I will look into.

Thanks for the help.

[gpounder]

Always thoroughly warm it up if you start it or it is better to let it sit.

I would be a bit concern that it quit after starting. That is a sign that something was not quite right. Did the pre heater come on? did you wait for it to come on? The pre heater can go bad, there is a relay that can fail or the heating element can fail. I had a bad injector that only missed when it was cold but the engine always started and ran.

Note: This is not a block heater rather this heats the air in the intake manifold.

[jleonard]

Originally Posted by wolfe10

Do NOT start a diesel engine unless you can drive 25+ highway miles.

.

Where did that come from? I have and have had diesel trucks for many years as daily drivers and most of my trips were way less than 25 miles, and most not highway miles.
When you need to drive a diesel, drive it. But don't start it every week just to let it idle because that's not good for them.

[wolfe10]

Originally Posted by jleonard

Where did that come from? I have and have had diesel trucks for many years as daily drivers and most of my trips were way less than 25 miles, and most not highway miles.
When you need to drive a diesel, drive it. But don't start it every week just to let it idle because that's not good for them.

Not sure we are saying anything different.


A daily driver is very different from a motorhome in terms of start/run cycles and getting the oil up to operating temperature.


Certainly agree with your last sentence! That is my point as well.

[Camp CA]

Diesel engines can sit a long time between operation......I have left my sailboat and truck diesel engines sit for 3 years at a time while overseas and when I returned they started right up (with a fully charged battery).

[Ambetter]

Sounds like you had some air in the fuel system. That’s how a diesel acts with air in fuel system. Check and make sure your fuel filters are tight.

[bigb56]

You certainly don't need a block heater in Southern Arizona. As far as the fuel, if you buy your fuel in the same area you will be storing it then the blend will be suited to the area, and in Southern Arizona you will not have gelling issues unless we get down in the teens, and even then doubtful. I store mine here in Tucson with no problems, some Optilube in the tank and a few drops of Biorbor treatment then fill tank to the brim and let it sit with a battery maintainer for chassis and house batteries.

Your rough running could be caused by several issues, one could be low battery voltage, another likely suspect on your OM642 is a carboned up EGR valve. The EGR valve can be cleaned if you are a DIY, it is important to clean not just the vanes on the rotary valve but the shaft that goes thru the exhaust port to the actuator motor, most people don't know that and the shaft will carbon up and become sticky. See link below. Don't ask the dealer to clean it, they only install new ones for big money, and there has been a shortage for a long time so they may not even have one. Actually yours should still be covered under the emissions warranty unless you have a lot of miles on it already, so if you experience the problem again I would take it in. Another symptom of the carboned up EGR is an intermittent hesitation when accelerating.
Don't rule out low battery voltage, the Sprinter has a fair amount of parasitic loads and should be kept on a maintainer or pull the battery disconnect by the accelerator pedal when storing.

https://sprinter-source.com/forums/i.../#post-1215013

[twogypsies]

RVs sit without moving in RV parks for 3-4 months during the season.

Don't start it unless you'll be taking it for a LONG drive.

bigb56, above, who has a Sprinter gave you good information.

[Crasher]

Only a motorhome owner will ask this question. The correct answer is "Never start an engine unless you intend to use it". That's how farmers and other business owners that use diesel powered equipment to make a living operate. That diesel engine in the motorhome is no different than the engine in a John Deere tractor or an irrigation power unit that sits idle for 6 months without starting. But, some MH owners just can't sleep well if the don't start the engine every 3-4 weeks. Totally unnecessary.

[Ray,IN]

Originally Posted by wolfe10

Do NOT start a diesel engine unless you can drive 25+ highway miles.


While a diesel can reach operating temperature of the COOLANT without driving, it can not get the OIL up to high enough temperature to get rid of the moisture that is a normal byproduct of combustion.


Same for your diesel generator-- when running it for exercise, operate it on 50+% load for the same reason.