We own a 2008 Nimbus CE338 with a 400hp Cummins ISL. Current oil has been in the coach & genset for almost a year now but have driven less than 3,000 miles. Is it absolutely necessary to change the oil yearly or could I possibly push it to 1-1/2 or 2 years without fear of engine damage. We are fulltimers but didn't leave our home area for over 4 months this past year. I cranked up the coach once a month and let it run for about an hour each time, same with the genset (under load). What do you techies think about stretching the oil change? Currently headed to Nacogdoches for our yearly maintenance/repairs. Any suggestions? Gary & Denise
OK, couple of points.
Worst thing you can do is start and just let the big diesel idle. It can NOT get the oil up to operating temperature except under load (read that 25+ highway miles). If you can't do that, don't start it, as all you are doing is adding moisture (a normal by-product of combustion) to the crankcase.
With that exception/if you are not adding moisture to the crankcase, I have no problem in your going 1.5 or even 2 years between changes. More a common sense thing than a rule book thing.
Boy you opened a can of worms! JMHO you could easily extend your drain interval to at least a year and a half, I'm sure Oil sampling would more than support it. Others I'm sure will chime in.
According to the lubrication industry, more engine wear occurs right after changing oil. But like Brett said moisture is the real problem.
Related question:
The hydraulic oil and filters for the engine fans and power steering seem it would not have much contamination over time (unlike engine oil). How often is it really needed to be changed? (2003 U320)
About hydraulic oil and filters ... I read three years. I did mine after we owned the coach for five years when I found out. Looked like new oil ... no grit or residue in the tank. It is most likely an issue of getting moisture in the oil over time. Easy to do yourself. Filters and gasket were inexpensive.
If you fill your oil filter before putting it on, the start up will be the same as a normal start.
Gary,
Because of your storage protocol, I'd change your oil now(you could skip the filter change), then follow the other Brett's advice and go two years.
I'm familiar with this report, its one of those counter intuitive things that just don't seem right, kind of like air filters, dirty ones filter better than clean ones, so changing results in higher rates of contamination until filter media is loaded. But, once again, each person decides whether they want to follow the scientific method, or gut instinct.
Results weren't due to putting a dry oil filter on.
You can skip the oil change this year. Ive worked on heavy diesels my entire life and i always change based on mileage/hours, not time. I plan on running the engine oil for at least two years, at my current 10,000 miles per year. That gets me well within CATs recommended 2500 gallons of fuel between changes, which is 23k miles at my mpg. I will do an oil analysis to ensure everything is good with my plan as well.
It's a myth that oil pressure is what keeps metal from touching in an engine. It's the oil film created by motion that separates the parts. Splash lubrication works on small engines. There is still oil on the internal components when starting an engine, even before oil pressure builds up.
Usually the most sensitive part of the engine to oil starvation is pistons/cylinders that get scuffed.
We crank our engine for a few moments without starting, by manually keeping the fuel solenoid from opening with a dash push-button switch. Not sure if it does much, but the idea is to pump some oil around before combustion.
For those that sit for an extended period of time an electric pump pre-oil system might be a good addition to the engine.
You could then prevent a dry start.
I remember reading something about this in a Cummings manual.
Most big stationary engines have pre-lube pumps AND post lube pumps to cool turbos.
Yes, in the early turbo days you could buy a simple pressurized tank that had a solenoid valve that would fill with oil while running, solenoid valve would close when engine was turned off, and pre-pressurize the engine as soon as the starter engaged and simultaneously opened the solenoid or slightly sooner if a time delay relay was added.
We added a PreLuber pump to our Dodge 440 Georgie Boy motorhome. We did the install ourselves, and it had an automatic timer that ran the pump until pressure was sensed and only then the starter engaged.
Oil accumulators are available from most racecar shops and are easy to install. Pre-lube with the push of a button or turning on the ignition.
Seams like we have gotten way past the original question about oil change!
No intent to get away from the original point.
Just thinking that if you sit for say three months then pre-oil to prevent a dry start you would not add as much contamation to the oil as say three or four short cycles of running but not driving and warming up to normal temperatures.
This method may effect how much longer you would feel comfortable to go between oil changes.
Myself I like to change all fluids at the manufacturers recommended time.
Relative to starting the engine periodically, before doing that, turn on the engine block heater the night before. It seems to do the job for me. I will turn on the block heater before starting the engine to warm up the oil which allows the oil to circulate quicker and minimizes the water (condensation) in the oil. Leave it on for a while after running the engine just to help remove more moisture. I run a bypass filter also which helps in that regard. I run with Delo 400, 15W40. That is what the people that designed and built the engine (CAT 3208TA) recommends.. Doesn't mean that something else isn't OK too, but I can't see changing. After 150,000 miles the oil is very clean for a diesel engine. Have a great day ---- Fritz
Thanks for all the replies, looks like an oil analysis is in the cards for the near future. Am going to hold off on the oil change and find a Cummins shop along our travel route. Thanks.
Gary,
IMO Brett Wolfe10 has the correct answer. If you start it, drive it for 20/25 miles to get everything warmed up and evaporate any moisture in the oil. My engine manual says to disconnect the wire plug to the fuel shut off and crank the engine until you see oil pressure if the engine has not been started in 7 days. Then reconnect the plug and start the engine. I believe the later engines like yours will not start until oil pressure is detected. Check your manual for what to do. Driving the coach once a month also helps to maintain the tires.
We have an engine like Jerry and being aware that there can be a value to crank without starting to build up a little oil pressure, we added a relay to do that from the driver seat. Put a N/C relay on the starter wire to the fuel shutoff, and with a push button switch activate the relay while cranking, leting up on the button to open fuel to start engine. We do not get enough oil pressure to move the gauge during this short 'pre-lub' cycle.
I would like to know where that damaging condensation inside a sealed crankcase is coming from? If short starts and runs without coming up to temperature are so damaging, how is the fifteen year old 7.3 liter diesel in my pickup still so healthy? I think nothing of starting it up and driving a half mile, a mile or two. Hundreds of thousands of times by now. In a coastal, humid, salt air laden environment. Two stroke Detroits, well maybe that can be argued.
I tend to agree... Some condensation is created from the combustion, no doubt, I too crank my tractors on the farm many times just to move them out of one barn to another. Sometimes they are run for hours and sometimes only minutes. Never worried about the moisture in the crankcase. In the summer hay season they are used often, in the winter months they sit a lot. If I need to crank them I do and have never worried about it. We have about 13 diesel tractors and the oldest is a 1959 Ford.
Experts have their reasons but I haven't experienced a moisture in the crankcase related problem.