^ Interesting info. Anyone else done any tests on this?

 

I'm one of them.

 

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Correct, acid and condensation (condensation assisting with acid formation) are a problem in any climate with short operating intervals. Yes it is more aggressive in colder climates but still a problem none the less. You can confirm it via oil analysis ($15-20 plus shipping) or just change it twice a year.


Tim

 

Small point, but I would suggest condensation in the oil sump does NOT assist acid formation.
In the past, it has been Sulfuric acid that has been the problem. It is formed in the combustion chamber from the sulfur in diesel fuel and the water formed by combustion during heating and cooling within the cylinders. (A diesel engine will product 1 gal H2O for every gallon of fuel burned.)
It takes heat to convert H2O and Sulfur into H2SO4.
The acid gets into the oil, here again more so in times past, through blowby and running down cylinder walls after shut down.
The above facts come from CAT Diesel Co testing, done over 20 yrs in the 60's and 70's.

I always use to recommend changing oil at least twice a yr. But with ULSD and tighter engines, I have changed to once a yr. JMO.

RJ

 

I did the once a year change for last year and was not happy with what I saw. Oil filter looked kinda slimmy looking. I am now back to twice a year. Do whatever blow your skirt up.....LOL

 

Where did I say that condensation in the "crankcase" contributed to acid formation?



Tim

 

Run a lightly used vehicle up to full operating temperature when you DO use it, and condensation will never be a problem. At the rate of less than 3k miles/yr. it will probably take a decade for a good-running engine to push the TBN down far enough realize any acid danger. I see no problem changing the oil yearly. With that few miles, I would probably take it two years. Just run it for at least 20 minutes to get it hot when you do run it, it'll be fine.

But there's plenty to be said for the "cheap insurance" (what's $50 worth of oil and filters these days anyways (?) - chump change!) and buying more oil to help the oil companies is a great angle for supporting our failing economy too!

 

I have recently found myself in a similar situation. My decision was to go the full year and do an oil analysis. I will change the oil again in July and do the oil analysis then. It will be about 5000 miles on Rotella T 15W-40 CI+4 oil with a bypass oil filter. My decision was based (with similarities and differences) on the fact the Mercedes Benz recommends 13K or yearly oil changes for our diesel car. In the end do what makes you happy! Cheers, Ed B

 

I don't have much faith in oil analysis ever since I had a customer bring a vehicle in with a locked up engine. The crankcase had filled with water and the contaminated oil was so thick it wouldn't run through a funnle with a half inch opening. Just out of curiosity I sent in a sample for analysis. The results came back that everything was in acceptable paremeters but advised repeating analysis at the next service interval. I caleed them up and questioned them about the water content and told them about the engine being locked up. They seemed to be embarrassed. So if you have faith that the test is actually being done correctly, then it could be a good tool. But if they are just taking your money and advising you to send them more money for subsequent service intervals, then it is a waste of money. Just change your oil and filters at intervals you feel comfortable with.

 

Change it once a year and don't worry with it. Don't wast your time on UOA on 1300 miles on the oil. Your could be worrying about something more important- like what mod you are doing next!

 

Once a year. I've had mine nearly 5 years, and I have 30+K miles on it. I average 6K to 7K a year, some years more mileage than others. I change it at least once a year, but I never exceed 5K miles on a change. All the diesel tractors I've ever owned recommend 100 hours or once a year oil changes. I guess that's where my thinking has come from.

As to oil analysis, never had one done. My Dad, who is nearly 80, has never had one done, and neither have any of my relatives. We've all been running diesel engines for many decades in tractors, semis, pickups, and about everything else you can think of. I've never seen or heard of a problem in my extended family on a diesel engine that could have been prevented by some "oil analysis".

Take care of them, service them, don't beat on them too hard, keep the rpm's down, and they'll take care of you. Not bashing those who think oil analysis is great, just saying in many years in the farming and construction business we've never done it and never needed it. Almost every problem we've ever had has been caused by some knuckle-head forgetting to put an air filter back on and those types of things (and one of those knuckle-heads was me when I was a teenage kid, probably thinking about my girlfriend, and forgetting to put an air filter back on my combine in the middle of wheat harvesting season. It lasted about 2 minutes after I started it back up and the engine froze. 14-hour days, 7 days a week, will take a toll on a young man after a few months. I took my beating and never did it again.)

 

[QUOTE=LeonT;2508703]
As to oil analysis, never had one done. My Dad, who is nearly 80, has never had one done, and neither have any of my relatives. We've all been running diesel engines for many decades in tractors, semis, pickups, and about everything else you can think of. I've never seen or heard of a problem in my extended family on a diesel engine that could have been prevented by some "oil analysis".

Keep the rpm's down, and they'll take care of you. Not bashing those who think oil analysis is great, just saying in many years in the farming and constructikn business we've never done it and never needed it. QUOTE]


First off, these are not the same diesels your dad use to drive. Totally different bread now a days. Second, keep the RPM's UP. Third, an oil anaylisis on todays diesels are extremely helpful. My father had failing injectors in his 05 and you would have never known. Not enough diesel in oil to notice when pulling the dip and looking at it or smelling it. UOA helped us discover an issue and solve before any other repairs were needed and before it left him on the side of the road somewhere.

 

We all run newer diesels now. We're not running 70's, 80's or even 90's stuff anymore. To each his own. You can sell anything on some remote possibility that something may go wrong. Life is a crapshoot. I've never felt enough of a threat to make it worth my time or money to get oil analyses done. I do have life insurance though, and I even bought an extended warranty on this truck. Offer me an extended warranty on a kitchen appliance or tv and I'll tell you to pound sound.

Not sure what you mean by "keep the rpm's up", but the standard we've always used is 1,800 to 2,100 rpm. I believe advocating that anyone routinely run a diesel truck above that is asking for trouble.

I'll live without an oil analysis. To you guys who think they're valuable, and time and cost-efficient, God bless you. Happy motoring.

 

[QUOTE=LeonT;2508875] I do have life insurance though,

Not sure what you mean by "keep the rpm's up", but the standard we've always used is 1,800 to 2,100 rpm. I believe advocating that anyone routinely run a diesel truck above that is asking for trouble.

QUOTE]



Should have elaborated a little more on the "keep the rpm's up." As in, not ideing for extended periods of time. There's still a lot of discussion about the idling being a negative or not. I'm on the side of saying is not all that great on any of the common rails.

 

Worst thing in the world you can do with a diesel is lug it. 1800 RPM is not lugging but it could be if you were pulling a steep grade with a heavy load. An EGT gauge will tell you what RPM's to be running. No guess work there. By the way, This is an industrial motor, It was designed to run wide open all day long by Cummins. For us to do it is kind of crazy though.