Engine - Used Lube Oil Analysis Guidelines & Warnings
Number: 85-3Section: 6A (VI)
Date: Sept., 1984
Subject: USED LUBE OIL ANALYSIS GUIDELINES AND WARNING VALUES
Model and Year: 1982-85 "C/K/P" TRUCK; 1983-85 "G" VAN, AND 1984-85 "D" (MILITARY) WITH 6.2L DIESEL ENGINE
TO: ALL CHEVROLET DEALERS
This bulletin is being issued to provide information for 6.2L diesel engine used lube oil analysis warning values and used lube oil analysis guidelines. Whenever the user performs a used lube oil analysis, it is important to note that the analysis charts are a guide to the condition of the lube oil and will not necessarily reflect the condition of an engine.
OIL AND FILTER RECOMMENDATIONS
Oil and filter change intervals are critical to the performance and durability of the 6.2L diesel engine. Consult the owner's and driver's manual for the correct grade, viscosity, and oil change intervals.
It is important that each specific vehicle, based on the guidelines found in the owner's manual/maintenance schedule, adhere to the recommendations regarding oil grade, viscosity, and oil and filter change intervals that most closely describe the vehicle's particular environment. Damage resulting from failure to do so is not covered by warranty.
USED LUBE OIL ANALYSIS PROGRAM
A used lube oil analysis program can be useful in tracking the condition of the engine lube oil. However, it must be noted that a used lube oil analysis will only result in an INDICATION of the condition of the engine after several analysis have been performed over a regularly scheduled interval, and comparison of the results suggests a pattern of abnormality.
NOTICE: An engine SHOULD NEVER be disassembled based solely on the results of a SINGLE oil sample analysis.
Abnormal concentrations of some contaminants such as diesel fuel, glycol (engine coolant), road salt, or airborne dirt cannot be tolerated for long periods in the lube oil. The presence of these contaminants can cause accelerated engine wear and/or deposit accumulation which could reduce engine life. The lube oil should be changed immediately if any contamination exceeds the warning limits.
Experience with specific engine applications is necessary to properly interpret any used lube oil sample analysis results. In evaluating used lube oil sample results, it is the change in value or deviation from the baseline data obtained from the new (unused) oil, that is important (same brand or mixture of brands).
FREQUENCY OF LUBE OIL SAMPLES FOR ANALYSIS
In order to obtain useful results from any lube oil analysis, it is imperative that the sample be taken at regular scheduled intervals. This enables like periods of time and mileage to be compared between samples and will result in a more useful indicator of the trending conditions of the engine.
USED LUBE OIL ANALYSIS WARNING VALUES
6.2L ENGINE
Wear Metal and/or
Coolant Elements Limit (PPM) Footnotes
Iron 500 (A)
Copper 400 (150)* (A) (B) (D)
Lead 115 (A)
Molybdenum 40 (A) (B)
Aluminum 50
Tin 90
Silicon 90 (A) (B) (C)
Chrome 45
Sodium 50 (A) (B)
Boron 20 (A) (B)
(A) Values allowed over lube oil baseline.
(B) These elements may be present in the new lube oil or coolant additive package.
(C) This value can be high on a new engine or a recently serviced engine due to "silicone" form-in-place gaskets.
(D) Engine(s) used in applications where extended idling is required may incur copper content levels up to 600/PPM.
* Lower value with 1985 model year engines because of revised rocker arm design.
CHEMICAL ANALYSIS
USED LUBE OIL ANALYSIS GUIDELINES
ASTM Warning
Designation Limits
Pentane Insolubles, Wt. % D-893 1.00
Carbon (Soot) Content Wt. % Max. TGA* 2.00
Viscosity at 40~C, cSt D-445
% Max. Increase
% Max. Decrease 40.0
15.0
Total Base Number
(TBN), Min. D-664 1.00
Total Base Number
(TBN), Min. D-2896 2.00
Water Content (Dilution), Vol. %, Max. D-85 0.30
Flash Point, of Max. Reduction D-92 40.0
Fuel Dilution, Vol. %, Max. ------ 2.50
Glycol Dilution, PPM., Max. D-2982 1000.00
*TGA = Thermogravimetric analysis used and recommended by Detroit Diesel. No ASTM procedure designation.