First time post, looking for thoughts on UOA

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2
Location
Minnesota
Below are the UOA results from the last 6 samples on a transit bus. The drain intervals are every 6000 miles. I'm curious what experts in UOA think about the results and if the OCI could be extended based on the soot load and viscosity level. MACHINE NAME: 1338 ENG LOCATION MACHINE TYPE: DIESEL ENGINE LUBE TYPE: MOB DELV 1300 SUPR 15W40 MACH MFGR: CUMMINS MACH MOD: ISL-280 RECEIVED: 06-AUG-14 REPORT: 08-AUG-14 12:42:42 SAMPLE NO: 2311-2-1402-6 TICKET NO: 5531,ENGCT5531 Machine Condition NORMAL Lubricant Condition NORMAL RECOMMENDATIONS ƒ Continue normal operation and regular sampling. ƒ Sodium level shows possible glycol. MISCELLANEOUS ƒ Lubr icant refers to oil, fuel, biofuel, grease, coolant or var nish. ƒ Our database indicates no site contaminant for this unit. SAMPLING HISTORY LabNo SAMPLE DATE DD-MM-YYYY TIME ON OIL / TSN TIME SINCE OVERHAUL / TSO OIL CHANGED (Y/N) PREVIOUS CONDITION MACH/OIL 996886 31-07-2014 6000 119447 Y (n/a) 981888 11-06-2014 6000 113453 Y N/N 965381 14-04-2014 6000 107647 Y N/N 951940 26-02-2014 6000 101608 Y N/N 937348 09-01-2014 6000 95804 Y N/N 925002 21-11-2013 6000 89684 Y N/N 1338 ENG Page 1 of 3 (SP) SPECTROSCOPIC ANALYSIS [ASTM D5185] (elements seen in ppm) TESTED ELEMENTS ARE:Fe, Cu, Pb, Sn, Cr, Al, Ni, Ti, Ag, V, Mg, Si, B, Na, Ba, Ca, P, Mn, Zn, Mo, Cd, K. Date(DD/MM/YY) 31-07-14 11-06-14 14-04-14 26-02-14 09-01-14 21-11-13 (n/a) (n/a) REF Labno 996886 981888 965381 951940 937348 925002 920847 Fe-IRON 25 17 15 14 13 16 1.0 Cu-COPPER 2.0 1.0 1.0 1.0 2.0 2.0 - Pb-LEAD 2.0 2.0 4.0 - 2.0 8.0 - Al-ALUMINUM 2.0 - - 2.0 - - - Cr-CHROMIUM 1.0 - 1.0 1.0 2.0 - 1.0 Ni-NICKEL - - - 1.0 - - - Mo-MOLYBDENUM 48 40 44 46 45 49 41 Si-SILICON 10 4.0 5.0 2.0 3.0 - 6.0 Mg-MAGNESIUM 798 701 776 820 677 915 859 B-BORON 26 16 30 22 25 35 89 Na-SODIUM 110 13 22 9.0 84 - - Ba-BARYUM - - - - - 1.0 - Ca-CALCIUM 1347 1149 1268 1304 1051 1519 1310 P-PHOSPHORUS 880 761 887 918 661 868 1001 Zn-ZINC 1073 951 1029 1143 807 1239 1111 K-POTASSIUM 19 6.0 6.0 6.0 - - 9.0 (FTIR) FOURIER TRANSFORM INFRARED ANALYSIS (Absorbance) Date(DD/MM/YY) 31-07-14 11-06-14 14-04-14 26-02-14 09-01-14 21-11-13 (n/a) (n/a) REF Labno 996886 981888 965381 951940 937348 925002 920847 SOOT 32 53 35 14 30 31 0 OXIDATION 31 22 23 18 22 24 15 SULFATE 29 26 26 23 24 27 19 NITRATION 13 11 11 9 10 11 6 SOOT (%) Date(DD/MM/YY) 31-07-14 11-06-14 14-04-14 26-02-14 09-01-14 21-11-13 (n/a) (n/a) REF Labno 996886 981888 965381 951940 937348 925002 920847 SOOT (%) 0.52 0.82 0.57 0.27 0.50 0.51 0.00 VISCOSITY/100 [ASTM D445] Date(DD/MM/YY) 31-07-14 11-06-14 14-04-14 26-02-14 09-01-14 21-11-13 (n/a) (n/a) REF Labno 996886 981888 965381 951940 937348 925002 920847 in cSt 100°C 14.56 14.21 14.41 14.46 14.06 14.33 15.14 TBN [ASTM D4739] (mg KOH/g) Date(DD/MM/YY) 31-07-14 11-06-14 14-04-14 26-02-14 09-01-14 21-11-13 (n/a) (n/a) REF Labno 996886 981888 965381 951940 937348 925002 920847 TOTAL BASE NO 5.77 6.22 6.47 6.91 6.27 6.30 9.53 HOT PLATE (%) Date(DD/MM/YY) 31-07-14 11-06-14 14-04-14 26-02-14 09-01-14 21-11-13 (n/a) (n/a) REF Labno 996886 981888 965381 951940 937348 925002 920847 WATER < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 FUEL [N-NEGATIVE, P-POSITIVE] Date(DD/MM/YY) 31-07-14 11-06-14 14-04-14 26-02-14 09-01-14 21-11-13 (n/a) (n/a) REF Labno 996886 981888 965381 951940 937348 925002 920847 FUEL N N N N N N N 1338 ENG Page 2 of 3 GLYCOL DETECTION [N-NEGATIVE, P-POSITIVE] Date(DD/MM/YY) 31-07-14 11-06-14 14-04-14 26-02-14 09-01-14 21-11-13 (n/a) (n/a) REF Labno 996886 981888 965381 951940 937348 925002 920847 GLYCOL DETECTION N N N N N N N
 
Messages
8,051
Location
Michigan
But glycol detection turned out negative. Soot is only 0.5%, and viscosity is still in the middle of the 40-weight range. Oxidation is low. Iron is only 25, and TBN is 5.77. Seems possible that the oil could go longer than 6000 miles.
 
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dnewton3

Staff member
Messages
8,512
Location
Indianapolis, IN
welcome Wear is in good shape. Extend the OCI by perhaps 50% (run to 9k miles). Keep an eye on the possible coolant issue. Best approach would be to be able to sample BEFORE a decision to OCI. Install a sample port and take a live sample. Analyze first, then decide.
 
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Streetside

Thread starter
Messages
2
Location
Minnesota
I appreciate all of the comments. Very helpful. What are the most important indicators to watch when extending the OCI? I'm thinking Soot,Viscosity,TBN,Silicon (SI)?
 

dnewton3

Staff member
Messages
8,512
Location
Indianapolis, IN
There is a difference between inputs and outputs. Soot, Vis, TBN, TAN, etc are all inputs to the wear factor. Total wear and wear rates will be affected by these, but they are not, in and of themselves, a reason to panic. These are tracking criteria to monitor and use as cautionary markers for continued and closer scrutiny. Wear metals tell you how things are progressing. They actually speak to the wear as it's happening as an accumulation. If you pick a set OCI and never vary, then you can simply look at the total numbers. But if you intend to extend the OCI (which is the best use of the UOA), then you'll have to conver to wear rates. Too many folks here use UOAs as toys and not tools; they don't understand how to take the data they glean and then appropriately utilize it in a manner of managing their maintenance program. And that's OK for them if that's what they want, but it's not useful at that point other than to entertain them. There are condemnation limits that exist for some of the big engine makers; these are self-determined by each: http://www.calrecycle.ca.gov/Publications/Documents/UsedOil/2008020.pdf page 11 You're not where near the limits. But again, keep an eye on coolant.
 
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