Usage:
Caterpillar has received a number of inquires regarding a clarification of the oil recommendations for 3600 Family of Engines.
Caterpillar Scheduled Oil Sampling (S·O·S) is highly recommended for determining oil change intervals on the 3600 Family of Engines. This article provides guidance on discussing the subject with Dealers and users.
Engine oil performs several basic functions in order to provide adequate lubrication. Oil works to keep the engine clean and free from rust and corrosion. It acts as a coolant, and provides an oil film cushion that keeps metal-to-metal contact a minimum, thereby reducing friction and wear. These are only the basic functions of oil. It is the particular demands of a given application and the special conditions under which an oil is used which largely determine the numerous additional functions it must perform. The selection of the correct oil for the 3600 Family of Engines is vital.
The selection of suitable lubricating oil should be given careful consideration, taking into account the quality of available diesel fuel. Additives in the oil play a very important role. The final performance characteristics of the oil depend upon the base oil and the additive used. The amount or type of additives used will vary according to the properties of the base oil and the environment in which the oil will function.
Market forces and legislative mandates have driven modern diesel engine technology to improve performance in two major areas: better fuel economy and lower emissions.
The improvements are achieved by attaining more complete combustion and better oil control. Improved combustion is the result of many enhancements; higher peak cylinder pressure is one of the major contributors. Better oil control, which also reduces oil consumption costs, is achieved by refinements in the piston, ring and liner.
Both of these performance improvements increase the demands placed on lubricating oil in a modern diesel engine. The higher cylinder pressure increases the loads and temperatures on engine components. Better oil control and reduced oil consumption means that the oil additive package is not replenished between oil changes because a smaller amount of new oil is added to the sump between oil changes.
Scheduled Oil Sampling (S·O·S)
S·O·S is a diagnostic tool used to determine oil performance and equipment wear rates. Caterpillar recommends using S·O·S at regularly scheduled intervals to monitor the condition and maintenance requirements of your equipment. The S·O·S program is a series of diagnostic tests which analyze used lubricating oils from the oil wetted compartments of the equipment.
There are several methods used to obtain S·O·S samples. NOTE: Sampling methods recommended are in preference order. If one of the first two methods is not feasible, use the drain stream method.
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- * Use an in-line sampling valve.
- * Use a sampling gun inserted into the sump.
- * Use the drain stream method when changing oil.
- * Use an in-line sampling valve.
When using the drain stream method to obtain an oil sample, take the sample after some of the oil has drained out and before the final drain oil. The oil at the beginning or end of the drain stream is not mixed well enough to be representative of circulating oil in the compartments and may carry debris that can give false S·O·S analysis results.
Lubrication Oil Change Intervals
In order to achieve maximum engine lube oil life and to provide optimum protection for the engine components, Caterpillar recommends using S·O·S to determine the oil change interval. S·O·S will help determine the proper oil change interval for your engine considering the type of oil, fuel, and operating conditions. The S·O·S program will determine oil change intervals based on condemning limits established by Caterpillar. Samples should be taken every 250 operating hours throughout the life of the engine.
The S·O·S program must include Infrared Analysis to determine oil change intervals. If your Dealer does not have Infrared Analysis capabilities, they can make arrangements for the testing or for approved alternate testing. Your Caterpillar Dealer is the best qualified source to interpret oil analysis data for the regulation of your oil change interval.
Lubricant Change Intervals Without S·O·S
If S·O·S analysis is not available, the limits in attached chart should be adhered to for oil change intervals for distillate fuel applications.
If oil analysis cannot be used and no other means of analysis is available, the oil change interval for heavy or blended fuel is 500 hours.
NOTE: Contact your Caterpillar Dealer for additional information.
There have been several different charts published that show the required initial oil change based on engine type used and oil sump size. In order to ensure that you are using the correct chart, follow the oil pan capacity and oil change intervals listed below.
