DD 60 series 12.7L, 6.1k miles, Mobil Delvac 1300 Super 15w40

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Received the latest used oil analysis UOA today for the 1995 DD 12.7L 60 series in our Prevost motorhome. Engine has 96k miles on it.

I think all is well. Oil and filters have been in place 22 mths and 6100 miles. No makeup oil was added. The oil in this report #4 is Mobil Delvac Super 1300 15w40. The oil filters are Fleetguard #LF9620.


Oil in reports #2 & #3 was for Chevron Delo LE 15w40. Report #1 was for a mix of HDEO that I had and wanted to use up at that time. I always use Fleetguard LF9620 oil filters. They are a full flow and bypass filter in one. Here's a link about that technology: LINK

I will leave the current oil and filters in place for at least another yr.

What say you ?
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We have some fuel dilution that wasn't present in previous uoa (Viscosity is still in check). Did you change something in the way you use that motorhome recently? Or maybe just the consequences of how fuel dilution is estimated now.
And do these DD engine still use silver bearings?

Not familiar with these engines, but I would keep an eye on fuel dilution (injectors?). Sometimes with diesel engines it's difficult to get rid of fuel dilution that is already present without changing the oil - again, not familiar with these engines in particular.
 
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You can pretty much just smell the oil to be able tell if you have any fuel dilution in a Diesel engine. Don’t really need any uao.
 

jetman

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Popsy, I saw what you saw. Viscosity is a little lower than new oil. I'll keep an eye on it.

I started towing a heavier and taller race trailer 8 mths and 800 miles ago. Trailer went from weighing 7000#s loaded to 10000#s loaded. Also, it is 2 feet taller than the MH so it catches more air. The old trailer was 2 ft shorter than the motorhome. Maybe these 2 factors have caused the mpg decrease? Maybe its a failing old original muffler, or maybe injector(s)? I was thinking about replacing the old original muffler with a less restrictive muffler.

I have no clue what the bearings are made of?

Mker, I have no experience sniffing oil. Wish you were here :)

Thanks
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Interesting that the oil has been in the engine since 2015, and has accumulated 18,600 miles. It's nice that you're not obsessively changing oil annually.
Iron wear is not high at all. The new reading is actually slightly less than the previous year's. Usual condemnation level that would trigger an oil change is at least 100 ppm Iron, so this is far from it.
Soot is stable at 0.2%, and is nowhere near being a problem.
Fuel dilution may trigger an oil change in a couple of years if it keeps increasing at 1% per year. But since fuel dilution has increased significantly from the last analysis, maybe something is starting up. Perhaps an injector that is leaking when the needle is seated. Are you running any kind of a fuel treatment to keep the injectors clean?
Oxidation has been steadily increasing. My lab flags oxidation as a minor concern when it tops 21.
 

jetman

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A_Harman, you obviously didn't read the words in my original post here. #4 is 22 mths old w/6100 miles, and is a different brand of oil than #3, #2, or #1.

#4 oxidation# when new is 15
 

jetman

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Here's the latest UOA report on this same load of oil that this post was originally about, Mobil Delvac Super 1300 15w40. I used Blackstone Labs this time. The oil was 2 yrs old w/8300 miles. 1995 DD 60 series 12.7L has 94,200 miles since new. I changed the oil and filters with the same.

What say you?

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I don’t know much about diesels but that report looks OK/good to me. Thanks for posting it 👍🤟🏻🍻🇺🇸
 
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Here's the latest UOA report on this same load of oil that this post was originally about, Mobil Delvac Super 1300 15w40. I used Blackstone Labs this time. The oil was 2 yrs old w/8300 miles. 1995 DD 60 series 12.7L has 94,200 miles since new. I changed the oil and filters with the same.

What say you?

View attachment 33013
It's sort of worrying that the KV100 has dropped out of the 40 grade. Even though Blackstone is not reporting fuel dilution, the viscosity has dropped slightly from the previous sample. Iron wear rate on the Delvac 1300 is about 2 ppm per 1000 miles, and is about the same as previous samples with different oils. I've been suspicious of Delvac 1300 since it has lower antiwear content than most other HDEO's. But it seems OK for you.
 

jetman

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It's sort of worrying that the KV100 has dropped out of the 40 grade. Even though Blackstone is not reporting fuel dilution, the viscosity has dropped slightly from the previous sample. Iron wear rate on the Delvac 1300 is about 2 ppm per 1000 miles, and is about the same as previous samples with different oils. I've been suspicious of Delvac 1300 since it has lower antiwear content than most other HDEO's. But it seems OK for you.
Yes it did thin out? I'll keep and eye on it with UOA.
 
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Keep doing what your doing that series 60 won’t really care what you put in the crankcase. Those pre emission S60s are probably the most reliable Diesel engine ever made. It will go a million miles at this point, or more. The only thing I’d worry about eventually is the bull gear but you’re no where near the mileage failure.
 
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It's heading towards the 30wt range but the engine doesn't seem to mind. Excellent diesel UOA.

Nice RV. It's my dream to have one of these, although my retirement budget is probably only going to support having one that's older with a 2 stroke. That's ok, I like to wrench on things.

The series 60 in the 90s Prevost coaches commands a fair premium on the marketplace as compared to an 8v92TA equipped one.
 

jetman

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Here's the 5th and latest UOA. 1995 Detroit Diesel 12.7L series 60. Mobil Delvac 1300 Super 15w40 10 mths and 6k miles since oil and filters were changed. I plan to put a couple of 1000 miles on the oil and Fleetguard LF9620 filters before changing.
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overall it looks like a good sample IMO. The viscosity at 12.7 is getting a little low, but nothing to worry about. The range for Mobil Delvac 1300 is 12.4 - 16.3 based on my samples.

Just my $0.02
 

jetman

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Latest Used Engine Oil Analysis Report

Sent in this sample for analysis earlier than I normally would. This time to Black-Stone Labs.net. The other analysis on this report is from two oil changes ago. I've been using Mobil Delvac 1300 Super 15w40 for the last few yrs.

Why early? My 96 Prevost bus/motorhome has a 2 gal reserve oil tank in the engine compartment with a clear site tube that began leaking. I had to drain 1.75 gal of 5600 mile used oil out of the engine (took the sample) and drained 1.75 gal of new oil out of the reserve tank into the engine so I could fix the site tube.

Engine doesn't consume any oil and isn't working very hard these days. Our local race track closed so I sold the stacker trailer, race car, etc. Now it only pulls my Toyota FJ 4 down behind it and gets 7 to 8 mpg. Total weight going down the road now 45k Lbs. Engine has a 10 gal capacity.

I didn't change the oil and don't plan to for another 2 to 5k miles.

Looks good to me, as it should. What say you?

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