Rotella T6 in a 2001 Cummins Dodge 2500, sample #3

[A_Harman]

Truck Odometer: 211300 mi
Miles on oil: 24000
No makeup oil added since last sample.

From Polaris Labs.

Wear Metals @ 12k, 18k, 24k:
Iron; 41 ppm, 60, 71
Chromium; 3, 4, 5
Al; 4, 5, 2
Copper; 4, 6, 8
Lead; 1, 4, 9

Contaminants:
Silicon; 8, 11, 15
Sodium; 11, 15, 18

Multi-source metals:
Moly; 66, 76, 86
Boron; 41, 39, 30

Additive metals:
Mag; 1162, 1193, 1383
Calcium; 1053, 1114, 1227
Phos; 1136, 1188, 1303
Zinc; 1377, 1451, 1549

Fuel Dilution Soot Water
KV100 = 14.2, 14.8, 14.6 cSt
TBN = 6.7, 6.46, 5.55
Oxidation = 12, 13, 14
Nitration = 8, 9, 9

Polaris Comments: Moly and Calcium readings were flagged as being abnormally high for RT6, but no advisory for maintenance action.

The big difference on this oil sample interval was that I decided to not add oil until the level was down to ADD on the dipstick. I've always been diligent about adding a quart when the level dropped to halfway between FULL and ADD. I found that after the level gets halfway down, the consumption decreases. In the first 3000 miles of this interval, the engine used 1 quart, and in the next 3000 miles it only used 1/2-quart. I think from now on, I'll maintain the level at 1 quart down from FULL.

I went ahead and did the oil and filter change at 24,000 miles, and refilled with 11 quarts, instead of the normal 12. Based on the Iron and TBN readings, I could have gone much longer, but this is the first time I have pushed the OCI this far, and I was beginning to lose sleep over it. Next OCI I think will be 30K miles, maybe more.

 

[Donald]

Originally Posted By: A_Harman
Truck Odometer: 211300 mi
Miles on oil: 24000
No makeup oil added since last sample.

From Polaris Labs.

Wear Metals @ 12k, 18k, 24k:
Iron; 41 ppm, 60, 71
Chromium; 3, 4, 5
Al; 4, 5, 2
Copper; 4, 6, 8
Lead; 1, 4, 9

Contaminants:
Silicon; 8, 11, 15
Sodium; 11, 15, 18

Multi-source metals:
Moly; 66, 76, 86
Boron; 41, 39, 30

Additive metals:
Mag; 1162, 1193, 1383
Calcium; 1053, 1114, 1227
Phos; 1136, 1188, 1303
Zinc; 1377, 1451, 1549

Fuel Dilution Soot Water
KV100 = 14.2, 14.8, 14.6 cSt
TBN = 6.7, 6.46, 5.55
Oxidation = 12, 13, 14
Nitration = 8, 9, 9

Polaris Comments: Moly and Calcium readings were flagged as being abnormally high for RT6, but no advisory for maintenance action.

The big difference on this oil sample interval was that I decided to not add oil until the level was down to ADD on the dipstick. I've always been diligent about adding a quart when the level dropped to halfway between FULL and ADD. I found that after the level gets halfway down, the consumption decreases. In the first 3000 miles of this interval, the engine used 1 quart, and in the next 3000 miles it only used 1/2-quart. I think from now on, I'll maintain the level at 1 quart down from FULL.

I went ahead and did the oil and filter change at 24,000 miles, and refilled with 11 quarts, instead of the normal 12. Based on the Iron and TBN readings, I could have gone much longer, but this is the first time I have pushed the OCI this far, and I was beginning to lose sleep over it. Next OCI I think will be 30K miles, maybe more.


I am changing the oil on my 1999 tonight. I am on the fence between T & T6. Do you have a normal filter or bypass?

Thanks for the timely (for me at least) post.

 

[SOHCman]

Originally Posted By: Donald
Originally Posted By: A_Harman
Truck Odometer: 211300 mi
Miles on oil: 24000
No makeup oil added since last sample.

From Polaris Labs.

Wear Metals @ 12k, 18k, 24k:
Iron; 41 ppm, 60, 71
Chromium; 3, 4, 5
Al; 4, 5, 2
Copper; 4, 6, 8
Lead; 1, 4, 9

Contaminants:
Silicon; 8, 11, 15
Sodium; 11, 15, 18

Multi-source metals:
Moly; 66, 76, 86
Boron; 41, 39, 30

Additive metals:
Mag; 1162, 1193, 1383
Calcium; 1053, 1114, 1227
Phos; 1136, 1188, 1303
Zinc; 1377, 1451, 1549

Fuel Dilution Soot Water
KV100 = 14.2, 14.8, 14.6 cSt
TBN = 6.7, 6.46, 5.55
Oxidation = 12, 13, 14
Nitration = 8, 9, 9

Polaris Comments: Moly and Calcium readings were flagged as being abnormally high for RT6, but no advisory for maintenance action.

The big difference on this oil sample interval was that I decided to not add oil until the level was down to ADD on the dipstick. I've always been diligent about adding a quart when the level dropped to halfway between FULL and ADD. I found that after the level gets halfway down, the consumption decreases. In the first 3000 miles of this interval, the engine used 1 quart, and in the next 3000 miles it only used 1/2-quart. I think from now on, I'll maintain the level at 1 quart down from FULL.

I went ahead and did the oil and filter change at 24,000 miles, and refilled with 11 quarts, instead of the normal 12. Based on the Iron and TBN readings, I could have gone much longer, but this is the first time I have pushed the OCI this far, and I was beginning to lose sleep over it. Next OCI I think will be 30K miles, maybe more.


I am changing the oil on my 1999 tonight. I am on the fence between T & T6. Do you have a normal filter or bypass?

Thanks for the timely (for me at least) post.

I was wondering about the filter change interval as well, how many times did you change the filter and what kind?

 

[A_Harman]

Just a normal PurOne filter for all 24000 miles.

 

[Donald]

Originally Posted By: A_Harman
Just a normal PurOne filter for all 24000 miles.


How did you take a sample? I tried to slide a sample tube down the dipstick tube and I assume there is something near the bottom preventing me from pushing the sample tube all the way in. I was thinking it had a slot for the width of the dipstick, but not a hole?

 

[A_Harman]

I crack open the drain plug on the oil pan about 1/4-1/2 turn, which lets the oil slowly run out. Before sampling, I thorougly clean the bottom of the pan with brake cleaner to make sure I don't get any contamination with road grime. I take the sample from the engine when it is still hot, with only ~10-15 minutes settling time from shutdown.

 

[Donald]

Originally Posted By: A_Harman
I crack open the drain plug on the oil pan about 1/4-1/2 turn, which lets the oil slowly run out. Before sampling, I thorougly clean the bottom of the pan with brake cleaner to make sure I don't get any contamination with road grime. I take the sample from the engine when it is still hot, with only ~10-15 minutes settling time from shutdown.


Hmmm...that seems the best way you can do it, but the oil still needs to run past the threads and washer neither of which you can clean.

 

[A_Harman]

The threads I clean when I completely drain it for an oil change. As you can see from the UOA data, the Silicon readings are not excessive and are gradually increasing with each sample, so I'm not getting any grit from road grime in the sample.

 

[dnewton3]

Several thoughts here:

1) get a Fumoto drain valve; great way to take samples and even makes OCIs easier. They are robust and reliable; I have one and I'm very impressed (no, I don't sell them or benefit from the sales)

2) excellent use of a syn! Seeking to get the your value out of the lube. Stretch out the OCIs! I would ask where your condemnation level is for the wear metals? The Fe is approaching a reasonble limit, but I'm curious where you've set the limit at? I would suggest perhaps 100ppm or a bit more, but it really hinges upon your comfort level. Stick with this plan for a while, and see what range/trends develop.

I would also mention that (for the distant future) you might consider a quality dino oil and perhaps see how it could compare/contrast to your current plan. There are some nice dino/Cummins UOAs where high OCI durations are seen performing quite well. To really know if your current plan is paying out, you have to know what the alternatives are capable of.

I like to see UOAs such as this. Using the tools and information to their proper intent. Keep it up!

 

[bullwinkle]

Originally Posted By: A_Harman
Just a normal PurOne filter for all 24000 miles.
I would LOVE to see pictures of that cut apart! To see how the media held up!

 

[Donald]

Mail me the filter and I will use my filter cutting tool to cut it apart.

What would you consider a reasonable OCI for this series of Cummins diesel engines and Rotella T and/or T6.

 

[A_Harman]

Originally Posted By: dnewton3
2) excellent use of a syn! Seeking to get the your value out of the lube. Stretch out the OCIs! I would ask where your condemnation level is for the wear metals? The Fe is approaching a reasonble limit, but I'm curious where you've set the limit at? I would suggest perhaps 100ppm or a bit more, but it really hinges upon your comfort level. Stick with this plan for a while, and see what range/trends develop.



We discussed condemnation limit for Fe in the string where I posted the 12k mile UOA. I was shooting for at least 100 based on that.

 

[A_Harman]

Originally Posted By: Donald
Mail me the filter and I will use my filter cutting tool to cut it apart.

What would you consider a reasonable OCI for this series of Cummins diesel engines and Rotella T and/or T6.


I have a Longacre filter cutter at home, but since I'm interested in finding out more about my engine's condition, I'm thinking about sending it out to have it professionally analyzed. The lab which has been doing my UOA's, Polaris, has a filter analysis service as well. If I can find out how much total debris has been caught in the filter, I'll be able to gauge how long I can run it.

I still don't know how long the OCI for RT6 in the Cummins 24-valve engine could be. At this point, I think that 24k is "reasonable", but not necessarily "optimum". Even at 24k miles, it could have gone longer. Fe was only up to 71, and I could have gone to at least 100, which knowledgeable people here will tell you is conservative. And there was still another 1.8 TBN depletion to go before hitting Polaris' limit of 3.7 (35% of virgin). I expect the next OCI could be extended to perhaps 33k miles.

I think that newer engines with EGR and DPF's would be harder on the oil than my old, emissions system-free engine. EGR in particular is very bad at sooting up the oil.

 

[dnewton3]

Originally Posted By: A_Harman
Originally Posted By: dnewton3
2) excellent use of a syn! Seeking to get the your value out of the lube. Stretch out the OCIs! I would ask where your condemnation level is for the wear metals? The Fe is approaching a reasonble limit, but I'm curious where you've set the limit at? I would suggest perhaps 100ppm or a bit more, but it really hinges upon your comfort level. Stick with this plan for a while, and see what range/trends develop.



We discussed condemnation limit for Fe in the string where I posted the 12k mile UOA. I was shooting for at least 100 based on that.



My apologies; I look at so many UOAs I forget which ones I've seen previously. Sorry about that. 100pm would be a fair and reasonable limit.