The Color of Oil

Topic: The Color of Oil (Read 1185 times) previous topic - next topic

The Color of Oil

May 03, 2015, 06:29:54 pm

Took the coach for a spin today. Back at home base, checking the fluid levels, a question came to mind. The engine oil on the "BIG" engine (Cummins 8.3) is black after about 5000 easy miles. The engine oil on the 10K generator (Kubota 4-cyl) is still transparent golden color after 110 hours of operation. Both diesels, running the same oil, burning the same fuel...

Why the big difference in color?

Re: The Color of Oil

Reply #1 – May 03, 2015, 07:13:47 pm

Main engine: 5,000 miles divided by 8 MPG= 625 gallons of diesel burned.

Generator 110 hours times .5 GPH= 55 gallons of diesel burned.

Re: The Color of Oil

Reply #2 – May 03, 2015, 09:16:15 pm

Thanks, Brett! I didn't consider that factor.

Re: The Color of Oil

Reply #3 – May 04, 2015, 09:39:37 am

Main engine: 5,000 miles divided by 8 MPG= 625 gallons of diesel burned.

Generator 110 hours times .5 GPH= 55 gallons of diesel burned.
[/quote]

Brett,
Being argumentative this morning......
Wouldn't the amount of oil, 5 qts vs. 38 qts water down that comparison? Actual equivalent around 420 gallons?

I to have been shocked at how quickly a diesel turns the oil pitch black.....

David

Re: The Color of Oil

Reply #4 – May 04, 2015, 10:26:37 am

Quote from: ratbug – May 04, 2015, 09:39:37 am

Main engine: 5,000 miles divided by 8 MPG= 625 gallons of diesel burned.

Generator 110 hours times .5 GPH= 55 gallons of diesel burned.

Brett,
Being argumentative this morning......
Wouldn't the amount of oil, 5 qts vs. 38 qts water down that comparison? Actual equivalent around 420 gallons?

I to have been shocked at how quickly a diesel turns the oil pitch black.....

David

Or, looking at this from another perspective: 5000 miles divided by 60mph makes 83 hours on the engine vs. 110 on the generator.

Re: The Color of Oil

Reply #5 – May 04, 2015, 11:33:26 am

Each engine has the appropriate amount of lubrication to do it's job. Each engine burns the appropriate amount of fuel to do it's job (we hope). Therefore the the only real variable is the total volume of diesel burned.
Ergo: Brett's argument is correct, the reason engine oil turns black.

Re: The Color of Oil

Reply #6 – May 04, 2015, 12:37:20 pm

If it didn't turn black we wouldn't be embarrassed enough to change it when needed

Re: The Color of Oil

Reply #7 – May 04, 2015, 05:13:53 pm

Quote from: Horace B. Cupp – May 04, 2015, 11:33:26 am

Each engine has the appropriate amount of lubrication to do it's job. Each engine burns the appropriate amount of fuel to do it's job (we hope). Therefore the the only real variable is the total volume of diesel burned.
Ergo: Brett's argument is correct, the reason engine oil turns black.

My thoughts of oil "staining"

is directed more towards the amount of oil that would be contaminated by the same amount of diesel burned. Generator holds what I've found to be around 5 qts...55 gallons burned... 11 gallons burned per quart of oil. Cummings holds around 38 qts........ 16.4 gallons burned per quart of oil Not as much difference to me as seeing 625 vs. 55........ 8% . 16.4 vs. 11........ 67%

If there's any relation to blackness of oil and amount of fuel burned...it should matter

surface area of oil rings, blowby, variables all are.

David

Re: The Color of Oil

Reply #8 – May 04, 2015, 07:02:15 pm

Interesting discussion - If it helps the "group analysis" any, here's more data (on my coach):

Total miles: 169,500 (original rings, runs great, doesn't "roll coal")

Total engine hours: 4050

Total generator hours: 1310

Re: The Color of Oil

Reply #9 – May 04, 2015, 11:27:51 pm

Diesels turn oil black...it's just what they do!

Re: The Color of Oil

Reply #10 – May 05, 2015, 03:16:25 am

I have about 2000 miles on my M11 since the last change. I use the Rotella Synthetic (T-6?).
I have a Amsol double (2 large filters) by-pass oil filter set-up.
My oil looks like I just changed it.
I use a Fleetguard main oil filter on the engine

Re: The Color of Oil

Reply #11 – May 05, 2015, 08:52:57 am

isn't mathematics wonderful, interesting, and convincing for any point of view :-)

Re: The Color of Oil

Reply #12 – May 06, 2015, 10:01:41 am

I have 3 ISX engines that have oil pans that have low areas in the back of the pan.. The place on the pans holds about 2 to 3 quarts of dirty oil that does not drain during oil drain... The cummins people missed this on my 09 and 2010 engines... It grates me to no end to have dark oil immediately after a change.. I can fix it by pulling the pans.. plating the low area drilling and threading a 2nd drain hole... we have talked about doing this for a year but there are always more pressing issues. Any of you with these model ISX engines may have the same.

Re: The Color of Oil

Reply #13 – May 06, 2015, 10:31:56 am

Quote from: Lon and Cheryl – May 05, 2015, 03:16:25 am

I have about 2000 miles on my M11 since the last change. I use the Rotella Synthetic (T-6?).
I have a Amsol double (2 large filters) by-pass oil filter set-up.
My oil looks like I just changed it.
I use a Fleetguard main oil filter on the engine

How often do you find that you need to change out the bypass filters? I've been intrigued by this for awhile but have been kind of put off by the expense.

Re: The Color of Oil

Reply #14 – May 06, 2015, 01:33:28 pm

I change my Amsoil bypass filters every 2 yrs (or when miles predict it).
Do not look at it as an expense but safety issue, just like all the other things we have to do if we want a coach that is dependable.
JohnH

Re: The Color of Oil

Reply #15 – May 06, 2015, 10:07:49 pm

I think the extended drain filters have a bypass filter built in.

Re: The Color of Oil

Reply #16 – May 07, 2015, 02:51:08 am

Quote from: rsihnhold – May 06, 2015, 10:31:56 am

How often do you find that you need to change out the bypass filters? I've been intrigued by this for awhile but have been kind of put off by the expense.

I changed mine 2 years ago. As I stated the oil looks like I just changed it. I replace the engine oil filter each year regardless of the miles (usually very low). I will send my synthetic oil sample into the the lab and have it analyzed after I get the coach out of storage and drive it enough to get it hot.

I will probably change the by-pass filters next year, but I doubt they will really need the change.

Re: The Color of Oil

Reply #17 – May 08, 2015, 05:42:37 pm

Quote from: krush – May 06, 2015, 10:07:49 pm

I think the extended drain filters have a bypass filter built in.

Yeah the LF9009 fancy venturi filter that we can use on our coaches does have a bypass built into it but that filter doesn't remove particles anywhere near as small as adding the Amsoil bypass filter kits which are 2 micron IIRC. I guess at 2 micron filtration, the Amsoil filters are catching all the soot out of the oil and allowing it to remain honey colored after thousands of miles.

Thanks for the responses on this from people who have them, I may end up buying into it.

Re: The Color of Oil

Reply #18 – May 08, 2015, 06:26:50 pm

2006 Phenix 525 ISX engine.
I have been changing the oil at least every 15k miles. I have been told that I don't need to do it that often.
I never get the same answer on change frequency even from the same facility.
After the last change, the coach was moved from the front to the back of the facility, Cummins, and then back to the front.
I check the level just to make sure, and the oil was already black. I was told that is normal. I have been wondering for the last year if the oil was actually changed. I'm going to have it done next month, and watch.
Whats this thing I read below about 3 gallons of undrainable oil with the ISX?

? It's difficult to imagine that Cummins would design something like that.

Re: The Color of Oil

Reply #19 – May 09, 2015, 03:20:14 am

Quote from: rsihnhold – May 08, 2015, 05:42:37 pm

Yeah the LF9009 fancy venturi filter that we can use on our coaches does have a bypass built into it but that filter doesn't remove particles anywhere near as small as adding the Amsoil bypass filter kits which are 2 micron IIRC. I guess at 2 micron filtration, the Amsoil filters are catching all the soot out of the oil and allowing it to remain honey colored after thousands of miles.

Thanks for the responses on this from people who have them, I may end up buying into it.

My 320 came with the Amsol by pass filter set-up so I don't have a before and after view point.
From what I can "see" It does seem to do a good job.
I will know better after an oil analysis, but I need to rack up some miles first.

Re: The Color of Oil

Reply #20 – May 09, 2015, 11:30:43 am

Unless you drive your RV frequently, dino oil will give the best protection against oil stripping (running off parts during periods of storage). Synthetics will give the best wear protection and won't coke and damage the turbo but will run off engine parts during storage and won't lubricate well in the first critical seconds after starting periods of storage. They may also not provide corrosion protection that dino oil does because of this. A pre-lube system would provide the startup protection and partially overcome any objections to them.

Most aircraft engines don't recommend either semi-synthetic or full synthetic oils for this reason even though they have many corrosion prevention additives.

Pierce

Re: The Color of Oil

Reply #21 – May 11, 2015, 05:29:45 pm

Not 3 gallons Bob... More like 2 quarts.. You can easily look at the bottom of your pan and tell if it's low in the back as my ISX's are.

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