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Topic: Should I Change the Oil or Not (Read 1290 times) previous topic - next topic

Should I Change the Oil or Not

I just noticed that almost exactly a year ago I changed the oil in the M11 - in the same Speedco I planned to go to today.

And that I put only 5,000 miles on it since. Half of the time it was in dry desert El Centro.

Is an oil change really necessary?

best, paul

Re: Should I Change the Oil or Not

Reply #1 –
Paul, What did your oil analysis show when you changed 5K ago ?  Use this as a guide, it took me a few changes but the oil analysis showed me that 9 to 10 K was the time to change oil in my 8.3.  Yours may differ.
Gary B

Re: Should I Change the Oil or Not

Reply #2 –
Paul,

From Cummings website:

Every 500 hours, 6 months, 12,000 miles or 19,000 km:
Replace:

    Lube Oil
    Lube Filter
    Fuel Filter
    Coolant Filter (C Series only)
    Drain water and sediment from fuel tank(s)

Having said that I think that 6 months is excessive.  If in doubt take an oil sample and send it to an oil analysis company.  If you start the engine, drive a good distance and get the oil hot then stop then you are probably OK.  Cummings are looking at a worst case scenario.  IE: Lots of start stop driving with many cold starts. If you are going to go a long distance on this trip I would change it to be safe.  Without analysis you just don't know if anything is contaminating the oil.

A good lab:

Blackstone Labs

Keith

Re: Should I Change the Oil or Not

Reply #3 –
Which is an excellent reason to buy a coach with a Detroit Diesel two cycle engine, cuz you can supposedly go 100,000 miles between oil changes according to Detroit Diesel. This would save you a fortune in oil changes over the life of the coach. You have to change your oil filter every 25,000 miles and you have to use the correct oil and filter. I'm still gonna send an oil sample in to the laboratory just to be sure, but the engine manufacturer should know what's best for their engines... This information won't help those of you who have already bought a coach but for someone trying to decide which engine they want this would be very important.

Re: Should I Change the Oil or Not

Reply #4 –
Motors are expensive, oil is cheap

Re: Should I Change the Oil or Not

Reply #5 –
Quote from: Tim Fiedler –
Motors are expensive, oil is cheap

Tim could not have sent it better. During a long trip, I might let it go 10K but with shorter trips, I change every 7K. Costs less than $100 for filter and 7 gallons of Delo 100. Leaves me a gallon plus to carry along. Big trucks may go longer but they are constantly under way. RV usage is much harder on engine oil with short trips and long periods of storage.

Some owners also dump the used oil into the fuel tank to save money. I don't!

Pierce

Re: Should I Change the Oil or Not

Reply #6 –
I'm with Keith, Blackstone Labs is a great resource for oil analysis. The key item for whether a low-mile but long time-span oil change is necessary are several items in the oil additive package. These compounds fight the formation of acids that eat away at the bearings and kill engines that are not driven regularly. Blackstone tests the additive package and will tell you how much is left, and whether you can extend your change interval without risk.

Re: Should I Change the Oil or Not

Reply #7 –
Pierce, I hadn't heard that idea before. I can just picture me changing the oil. I somehow get myself under the coach with my oil pan that holds about two gallons. When the pan is close to full, I put the plug back in the pan, get myself and the pan out, go over to the fuel tank, dump the two gallons of oil in the fuel tank, then repeat the process several more times. If I'm lucky, maybe half of the used oil would end up in the fuel tank. The rest of it would be on the ground and on me. About the only "benefit" I can see is that I would get some exercise. Maybe I should just stuff the oil pan and myself under the coach, crawl back out, walk to the fuel tank, and repeat 10-15 times and just leave the oil alone.

Nope, that's too much like work. Time for a nap.

Re: Should I Change the Oil or Not

Reply #8 –
I'm lucky with the pit but driving up on blocks and using a 5 gallon container like for tractor fluid with a top and fill neck together with a fairly flat funnel for clearance will catch all the oil without trying to put the plug back in. An open container is also good to catch the oil from the filter. Tough to do with a plastic bag especially if the engine and oil is hot. Thin gloves are a must. Aircraft quick drains work in many applications but stick down on the Detroit pan.

I pre-fill all filters but not a must do.

At the department, we changed all trucks at 1000 miles. A lot of guys used it for oil changes on their cars.

About noon here. Time for the first of the afternoon naps.

Pierce

Re: Should I Change the Oil or Not

Reply #9 –
I've used Blackstone Labs to analyze oil before the two most recent oil changes. Their current recommendation for our C8.3-325 is to run 12,000 miles after installation fresh Delo 400 15W-40 and send them a sample. We travel about 12,000 miles per year.

Most of my engine starts are associated with running 200-400 miles in a day on highways. If we don't travel for a month, I take the coach on a 20 mile exercise run that include about six miles of warm up on 40 mph roads, eight miles of 60-70 mph on a highway, and six miles of 40 mph roads to get back home.

Re: Should I Change the Oil or Not

Reply #10 –
Quote from: RRadio –
Which is an excellent reason to buy a coach with a Detroit Diesel two cycle engine, cuz you can supposedly go 100,000 miles between oil changes according to Detroit Diesel. This would save you a fortune in oil changes over the life of the coach. You have to change your oil filter every 25,000 miles and you have to use the correct oil and filter. I'm still gonna send an oil sample in to the laboratory just to be sure, but the engine manufacturer should know what's best for their engines... This information won't help those of you who have already bought a coach but for someone trying to decide which engine they want this would be very important.

Another potential problem for a prospective 6V-92TA buyer is what kind of oil has the last owner been using for changes? If you read the canister for the hydraulic pump, it's a 15-40 multigrade so many owners will also change the engine with that. Others, including shops, will use something like Delo 400, a high ash oil unsuitable for 2 cycles. I have seen the accelerated testing done with side by side photos of  piston/cylinder wall wear and injector follower wear done by using the incorrect oil vs low ash straight grade oil. A big difference.  The only way to check is to have a Detroit shop make a visual inspection otherwise, who knows what you have. Many will be like ours, with no record of any kind. I took a chance and it runs like a clock but down the road...

Fleet owners have to be on their toes to stay in business in a very competitive environment. RV owners are hit or miss and a lot of miss at that. Unless I read "Delo 100 #40" or other low ash oils printed in the log book, I would take everything the seller said with a grain of salt at best. In talking to two Sacramento Detroit Diesel shops about antifreeze, they said, "we just use the ordinary green stuff everyone else does".

Pierce

Re: Should I Change the Oil or Not

Reply #11 –
 ??? Really, pour the old oil in the fuel tank? :-\

Is that just DD?

Re: Should I Change the Oil or Not

Reply #12 –
Quote from: fouroureye –
??? Really, pour the old oil in the fuel tank? :-\

Is that just DD?
I talked with a guy who did that once.  He said he would never do it again due to the extra smoke out the tailpipe.

Re: Should I Change the Oil or Not

Reply #13 –
Quote from: fouroureye –
??? Really, pour the old oil in the fuel tank? :-\

Is that just DD?

No, way back when every soccer mom had to have a 300D wagon, owners that did DIY oil changes were stuck with the nasty, black stuff that you couldn't get off your hands. What was easier than to just put it back in the fuel tank? In those days, railroad locomotives were using the same bunker fuel that ships were. They had heaters in the fuel tank warm it before a cold start. Any kind of oil was fair game for the fuel tank in diesel cars then and has remained popular with a lot of owners. Naturally, besides introducing a lot of chemicals and metals to the fuel, it also takes it way out of spec for the ultra low sulfur diesel. Think it would be really marginal to try on the ultra high pressure common rail injection used in the later diesels now but I am sure people still do it.

Back from Fiji and OZ last month. You can't believe how the non-turbo diesels smoke. And most vehicle are diesels. In a poor country like Fiji, I'll bet most recycle the oil into the fuel.

I recall skiing at Mammoth Mountain where L.A. people would just leave their Mercedes idling all night after locking them. Otherwise, they would never start in the morning. 1980 slowly changed that as the quick glow glowplug was introduced. I noticed on Detroit 2 cycle piston and cylinder kits, pistons are available from 15 to 1 up to 21 to 1 compression ratio. High altitude generator, pump, farm owners fit the higher compression pistons so they will start well in cold winter condition.

How did I get off waste oil in the fuel tank? Oh, look, a chicken...

Pierce

Re: Should I Change the Oil or Not

Reply #14 –
As most of you know, I installed the Cummins Centinel system.  The used oil goes into the fuel tank, but in very small metered amounts.  Oil changes every 300K miles.  Special oil filter changes every 75K.

Re: Should I Change the Oil or Not

Reply #15 –
Brett, how many gal reserve(new oil) do you have?

Fortunately the PO changed over to amsoil :D

Re: Should I Change the Oil or Not

Reply #16 –
Well, I changed the oil as I thot I would. But Speedco did not have the fuel/water seperator filter, their brand S3230P, other brand FS19592. So with fresh oil would it be critical to replace the filter?

They also did not have the air filter, AF-954M, and encouraged me to shake the dust off it (they said they are not allowed to ;o)

best, paul

Re: Should I Change the Oil or Not

Reply #17 –
Quote from: Paul Smith –
They also did not have the air filter, AF-954M, and encouraged me to shake the dust off it

I hope you didn't (take it out just shake the dust off it and reuse it).  That is one of the worst things you can do.  It's also hard to pull that filter out and not get dirt on the wrong side of the filter (unless you are wiping out the housing and installing a clean filter).

Re: Should I Change the Oil or Not

Reply #18 –
It's hard to break old habits but study after study, backed up with wear analysis indicate that most oil is changed far more frequently than necessary.  Cummins, on one hand, gives the very conservative recommendation for frequent oil changes.  Then, on the other hand, they have the Centinel system which maintains the oil to a functional level of quality.  What is that level? 

"The oil replacement rate therefore varies in real time, to maintain oil quality at a level that approximates a typical 50,000 mile oil change interval regardless of the engine's actual duty cycle."

One very long running oil change study on a gasoline engine I followed had some surprising findings.  They ran extended oil changes, pulling samples for analysis every 1000 miles.  The highest rate of engine wear metals, without fail, occurred immediately after each oil change.  They found regular filter changes to be more effective than oil changes, with a midpoint filter change they were still at acceptable levels at 20K miles on oil.  This was a few years back, big iron v8.

Re: Should I Change the Oil or Not

Reply #19 –
I have been doing oil analysis (and coolant and transmission too) regularly and it indicates that more than 5,000 miles for oil changes is OK.  But I like to change it every year in the fall before storage no matter what the mileage. So far that works out to about 7,000 miles or so.  Our use is going up so oil changes will likely be more frequent. 

Oil changes are a lot cheaper than an engine rebuild.

Roger