Paccar mx 13

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I am new to this whole oil analysis stuff so i was hoping i could get some opinions on my report. Also i was wondering if i could lengthen my oil change interval? I appreciate the help
 

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Tell me if I'm reading this right - 40846km (~25000 miles) on the OCI? Looks like pretty low wear numbers. Jury's out on extending until some analysis experts come along.
 
Something is not right. If there are really 25,000 miles on the oil, then the FE wear numbers are not right. To low.

I would not go above 10,000 to 12,000 mile OCI without getting a TBN. TBN is critical to extending an oil change interval..
 
OTR truck with a huge sump and running multiple filters may well have a 25,000 OCI.
 
Show off!!!
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With regard to oil analyses, the Paccar MX13 is the lowest wearing heavy duty engine I've ever seen. I've seen several UOAs for that engine and this report is pretty typical. Extraordinarily low wear metals is nice, but the silicon is very good and there's no signs of antifreeze intrusion, either. Soot says 0, my reports run less than 1%, too, but I guess yours is most impressive. I'm not sure what your engine has for filtration, but those are great results.

I don't know what oil you're running and it doesn't matter. I no longer give much of a hoot about TBN and TAN, so I'm not concerned about the lack of it here on this report. All I can say is, feel free to add some miles (KMs in your case) and check again. It depends on your comfort level. Keep track of the oil on the dipstick, watch the coolant level closely, keep track of the air intake plumbing and barring any problems, you could most likely double the interval with ease. That's all up to you and how far you want to take it.

If you're not using CK-4 oil, I would encourage you to do so. It'll help you out with extended OCIs. It's amazing how well it prevents thickening of the oil in long runs, regardless of how much you work it.

Edit: if you don't have a vacuum pump for pulling a sample out of the sump via the dipstick tube, Toromont Cat could sell you one. That way you can pull samples during an OCI to keep close watch of the oil as you extend. No need to drain just to get a sample.
 
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Awesome thanks so much. Just wondering which numbers should i pay the most attention to for extending OCI and what would those values be?
 
First look for any indication of a problem; checking the soot, silicon, fuel, and oxidation (oil thickening). Excessive amounts of any of those can relay a problem. Your engine has something like 750k miles and while it could easily go twice that before needing an overhaul, it's enough miles that things could start to fail, or at least lose efficiency.

Right now, it appears that your engine is as healthy and efficient as my 400k mile Detroit. As long as it remains that healthy, you can safely add many miles/KMs to your intervals. Did you have to add any oil? How much? If you're pouring in gallons of oil for top-off, then that would skew things a bit. I overlooked "Shell" earlier, so I would guess that it's good ol' T4.

If the oil thickens much out of grade (over 16.3 for a 15W-40 I believe) then it may be time to change, or at least getting close. Just my opinion, but maybe not scientifically accurate. Caterpillar labs measure oxidation. If you were to get a sample of fresh oil tested and then test the subsequent used oil samples, I don't know what the condemning number would be for oxidation.

Excessive soot that overwhelms the oil's ability to disperse it will cause extra wear. If you have a bad injector (or two, three, etc), maybe a problem with EGR or the turbo, you could develop high soot and eventually high wear. Just something to keep in mind as your engine piles on the miles. Keep track of how the engine behaves, the fuel efficiency and the visuals to help keep yourself ahead of any problems before they get out of hand. Oil analysis is an excellent tool for finding problems early on.

Once you push the oil too far, it's going to show up in increased wear metals. One thing that many people go by is the TBN/TAN relationship. The theory is that once the acid number (TAN) exceeds the remaining base number (TBN), the oil is done. I'm in no position to say that's wrong, but I've never seen proof of it in my own results. It's certainly not something I can make a blanket statement about in either way, but I don't worry about TBN/TAN too much anymore. If I pay extra for those, it's mostly just for fun or pure curiosity.

Edit: to be more direct in answering your question about what values to look for; the closest I can get to that is the viscosity increase I mentioned above. And that's only my opinion. There are most likely condemnation points for the different wear metals (each engine model a little different), but I don't know what they are for the MX13. I highly doubt you'll ever reach any condemning numbers unless something goes wrong. There's probably a condemning soot number as well, just don't know what it might be. The oil is capable of handling quite a bit but I'm at a loss and couldn't say just how much at the moment. I'm way past my bedtime and need some sleep.
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Hey no problem i really appreciate your help. I have not had to add any oil between changes. And yes it is the t4 oil.
 
If you do extend the intervals, you could try adding 10k-15k Km to the 40k km OCI you have posted here, and continue to extend based on the results. There's an increased cost for learning what interval the oil is capable of in your engine, but it'll pay big dividends once you've got it figured out. The cost of pulling a couple (or a few) samples throughout the next interval is nothing compared to the cost of short OCIs.

dnewton3 is our resident expert analyst with lots of data and the ability to understand it. If you can follow up with future reports, there's help available here to help advise you on when to call it good.

I'm still fairly new to longer intervals, but it's going quite well and see no reason why you couldn't match (or go beyond) what I've been doing. I know there's a comfort factor to consider, too. It took me a few long intervals with good results to get used to it.
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Email Paccar and see what their condemnation limits actually are. That will give you some reference points to look for. Cummins was super quick to get back to me with data for my ISB6.7 in my 3500.
 
Originally Posted by TheTanSedan
Company I'm with has 60k OCI on this motor (2018-spec). T5 Rotella

If you have < 20% idle time and > 6 MPG, PACCAR recommends 120K KM/75K Mile OCI for 2017+ MX-13 engines.
 
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