62 Peterbilt, NT280B Cummins, Rotella 15w-40.

[Chris142]

Only 1400 miles on the oil but it's been in the engine since Feb. This is the truck I'm restoring and run it around the block once a week or so.

IMO the fuel is from a leaky injector. Thing runs rough when started untill the injector gets fuel through it.

My readings universal avg


Aluminum-2-5
Iron 4-24
copper2-4
Calcium 3027-2343
magnesium 18-63
silicon-2-5
phos 1032-988
zinc 1147-1109
barium 1-0

sus vis @210F 81.3--69-80
flash-395--410
fuel 1.5
insolubles-.3
Everything else is zero!

I pulled this sample out of the Luberfiner filter on the side of the cab. I Was expecting to find it quite dirty since It came from the dirty side of the filter. Was mainly concerned with coolant in the oil.



A month ago I pulled a loaded trailer to see how well the truck would pull. I really gave it a workout but it didn't seem to hurt anything.

I was a little concerned about the length of time that the oil has been in the truck but I think I can let it go till next Spring.

Not bad for a 44 yr old engine.

 

[1040 WreckerMan]

I wouldn't worry about the fuel. For an early Cummins 1.5 is not bad at all, in fact it's great considering you don't work the truck much. That engine will run very rough when it's cold, you'll probably notice some white smoke and once that goes away it will probably have some fuel slobber on the stacks. The engine needs quite a bit of heat to run correctly, and since the truck was built to work hard, running it around the block isn't quite enough.

Why do you think their is coolant in the oil? You didn't list any potassium and their isn't a "coolant" column listed. At any rate, most likely reason for coolant in the oil is probably going to be an oil cooler problem. In fact I just had the engine oil cooler side of a Cummins M11 apart today for that reason. UOA looks good, that engine will outlive everything thing else in your neighborhood probably.

 

[Chris142]

When I first got the thing it had quite a bit of coolant in the uoa. I know that the thing had sat for at least 8 yrs before I got it. It also had alot or iron in the oil.

The headgaskets do seep externally a little. I've heard this is quite common on old Cummins engines.

Now that I think about it I think it may have been rebuilt or had some major engine work back in 98 right before it was parked as this would show wear in metals and possibly coolant in the oil from replacing liners.

Anything that I didn't post was a zero. BTW the TBN was 12.4

 

[Chris142]

Here's the original UOA.

http://theoildrop.server101.com/forums/s...true#Post583162

I fergot to mention that I drove it to work today. It was right at freezing and it started right up. Tomorow it's going to a car show and I'll run it on the highway some.

 

[1040 WreckerMan]

I think you are fine as far a coolant leakage. I would certainly keep an eye on it, however the wear metals look too good for you to have a serious problem.

I believe that the NT280B was a wet liner, so the lower liner o rings might relax and seep a little from the long periods of inactivity, then swell and stop leaking after the thing has been run a bit. It wouldn't hurt it a bit to load it good and heavy every once in a while.

Although this engine survived many years of use with relatively little design change, even the late model engines that were based off the NT design were still somewhat old technology. They will seep oil and coolant, you will get fuel dilution (especially in light service as your truck is) and fuel slobber (raw fuel in the exhaust) and smoke. Unless it is doing one or more of those in excess I wouldn't worry. You say it runs well and your UOA looks great, I'd sleep easy. I still wish that truck was mine