3300 Generator Set Oil Level Maintenance And High Oil Consumption Caterpillar

Problem:

Improper oil level maintenance practices can lead to reports of high oil consumption on these engines. Changing to the new pistons [165-4262 Piston Body Assembly (15:1 compression ratio) or 168-4530 Piston Body Assembly (16:1 compression ratio)] with the 4 mm wide, higher unit pressure oil ring may not (by itself) reduce the oil consumption to a level that is satisfactory to the customer. In addition, there needs to be consistent guidelines for establishing what is considered to be high oil consumption. These guidelines can be used to determine candidates for possible field rework to the new pistons with new oil rings.

Solution:

Please use the following procedures for optimizing oil consumption, as well as establishing the level of oil consumption for these engines. These procedures can be used to determine whether or not the engine may benefit from upgrading to the new 4 mm oil ring pistons. The new 4 mm oil ring pistons are effective with 3304B (1PS625, 83Z11169) and 3306B (8JJ512, 9NR3283, 1RS630, 85Z14469) Marine Auxiliary Generator Set Engines and Generator Set Engines.

1. All oil level maintenance should be performed only when the engine is stopped, and after the oil has had a chance to drain into the oil pan from the cylinder block and the front gear train, and after the air in the oil has been allowed to dissipate (after approximately 20 minutes). If the engine is still running, a significant portion of the oil added will be hung up in the block and gear train. In addition, while the engine is running, the oil level in the pan actually is tilted and inconsistent. While the engine is running the oil in the pan is being pulled up on the right side of the pan and drawn down on the left side of pan because of crankshaft windage. This can result in inaccurate oil level reading on the dipstick. Only use the "Engine Running" marks on the dipstick to ensure there is sufficient oil in the pan to prevent a loss in oil pressure. DO NOT use the "Engine Running" marks on the dipstick for oil level maintenance.

2. Ensure the engine is level. This may be a problem with rental units. Typically, generator set engines are leveled at installation so this is not normally a problem.

3. Allow the oil level to drop to the "ADD" mark on the dipstick before adding new oil. Maintain the oil level below the "FULL" mark on the dipstick. Consistently adding oil to raise the oil level to the "FULL" mark can lead to overfill. This is because adding a hole quart/liter of oil can result in as little as a 3 mm change in oil level, depending on where the oil level is at the time (above the block/pan joint versus entirely in the sump).

4. Check the "Engine Stopped" calibration of the oil level dipstick at an oil and filter change. After new filters have been installed and the proper amount of oil added to the pan, run the engine for a few minutes. Then stop the engine and allow the engine to stand for a few minutes. Be sure the engine is level. Remark the "FULL" mark on the dipstick if necessary.

5. Pick a time each day for oil level maintenance (before or after a shift for example), and record oil and fuel usage consistently.

6. Oil consumption, as defined by Caterpillar, must always be in terms of the ratio of fuel burned, in liters or gallons per quart or liter of oil used. The minimum acceptable oil consumption, per Caterpillar, for the 3300 engine is "60 gallons of fuel per quart of oil" or "240 liters of fuel per liter of oil". Oil consumption only in terms of oil added per day is an unacceptable measure for oil consumption. This is because more oil will normally be consumed with higher load factor (higher fuel rate) operations.

7. On a new engine, try to allow at least 2 oil change periods (500 hours) of engine operation in the customers's typical application. During this period maintain consistent fuel and oil usage records to establish an oil consumption level. See Step 6. If the oil consumption level is excessive, use the Technical Marketing Information (TMI) screen to get a breakdown of the engine arrangement. Use this information to determine which 4 mm oil ring piston group is applicable for any repair.

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