MANIFOLD ASSEM. (rear) 4N5458 - Caterpillar

Oil Deterioration
Oil oxidizes naturally with time in service and the oxidation process accelerates with high temperatures. For these reasons, oxidation is often associated with long OCIs and/or high temperature operation. Oxidation results in oil thickening, formation of resins, piston deposits, loss of lubricating qualities, and accelerated wear. Highly oxidized oil can leave a honey-colored residue on crankshaft journals. Likelihood of oil filter plugging, filter bypass, and exposure of engine bearings to debris increases with increasing oxidation.As acids of nitrogen and sulfur form in the engine oil, these acids break down the additives in the oil and accelerate the oxidation process. These acids also create a corrosive environment where lead from engine bearings can leach into the oil.
Table 3
Oxidation Guidelines
Typical New Oil
Oxidation - UFM Monitor Compartment
Oxidation - UFM Action Required
Oxidation - UFM
Cat DEO CI-4 13 23 33
Cat DEO-ULS CJ-4 16 26 36
Cat DEO-ULS CK-4 21 31 41
Commercial CI-4 or CJ-4 or CK-4 X X+10 X+20
Table 4
Common Chemical Wear Factors
Item No Action Required Monitor Action Required
Oxidation(1) ≤ 23 UFM 24-33 UFM ≥ 34 UFM
Sulfation ≤ 27 UFM 28-33 UFM ≥ 34 UFM
Viscosity < 2 cSt 2 cSt ≥ 3 cSt
(1) Use these Oxidation guidelines if the new oil Oxidation value is unknown.Table 4 lists factors related to the proper chemistry of diesel engine oil and certain guidelines for monitoring those factors.
Illustration 9 g06216468Oil deterioration can also be caused by deposits and wear in the cylinder packs. Badly worn cylinder packs may exhibit: heavy deposits, broken piston rings, and polished cylinder liners. These cylinder pack issues will increase blowby. Oil samples from worn cylinder packs will show high oxidation, high soot, and increased viscosity.Resolve and Proceed
Table 5
Quick Reference Troubleshooting Guide
Oil Analysis Result Probable Cause Notes and References Recommended Action
High Pb and high Si, Al Mechanical Wear : Dirt/Debris Introduced Through Service or Operations Review service and maintenance practices. Inspection of magnetic plugs and oil filter elements are recommended.
Check the cleanliness of the fill oil. Check the cleanliness of the repair facility and repair parts. Alter service or maintenance practices to eliminate dirt/debris introduction. Resample oil to confirm wear metal concentrations return to acceptable levels. Consider bearing replacement if the dirt/debris introduction was severe (high concentration, long duration, and so on) and/or if the engine is not close to PCR target.
High Pb and high Si, Al, Fe, Cr Mechanical Wear : Dirt Ingestion Through the Air System Refer to Service Magazine, SEPD0712, "Procedure to Test Air Induction System". Repair source of dirt ingestion and resample oil to confirm wear metal concentrations return to acceptable levels. Consider bearing replacement if the dirt ingestion was severe (high concentration, long duration, and so on) and/or if the engine is not close to PCR target.
High Pb and high Cu Mechanical Wear : Bronze Thrust Bearings or Bronze Bushings Bushings, bearings, and thrust washers in rear gear train and air compressors are common sources. Larger particles can often be observed in filter media. Check filter media and magnetic plugs for presence of larger particles. Replace worn