2004/12/01 Caterpillar

Engine:

3116 (S/N: 4KG1-UP; 1SK1-UP)

3126 (S/N: 1ZJ1-UP; 6MK1-UP; 8NM1-UP; 6SR1-UP; 4EZ1-UP)

Updated information has now been entered into Operation and Maintenance Manual, SEBU6251, "Caterpillar Commercial Diesel Engine Fluids Recommendations", "Engine Oil (3116 and 3126 Marine Engines)".

Caterpillar only recommends oil viscosities of single weights for engines with mechanical unit injectors. This includes all 3116 and 3126 Marine Engines that begin with the following serial number prefixes: (S/N: 6SR), (S/N: 8NM), (S/N: 4KG), (S/N: 1SK), (S/N: 1ZJ), (S/N: 6MK) and (S/N: 4EZ)

The updated article is given below.

Recommendations

Caterpillar does not recommend the use of multigrade oils in the 3116 and 3126 Marine Diesel Engines that use mechanical unit injection.

Multigrade oils use high molecular weight polymers as viscosity index improvers.

When the crankcase blowby flows through the turbocharger and the aftercooler, the viscosity index improvers in the oil vapor can adhere to the turbocharger compressor and aftercooler core.

The fouling of the turbocharger and aftercooler can cause reduced air flow, loss of power, and increased black smoke. The emission of black smoke results in buildup of soot on the transom of the boat.

Note: Caterpillar recommends the use of single grade oils with the API CF-4 classification for all 3116 and 3126 Marine Engines unless crankcase blowby has been routed completely away from the air cleaner inlet.

Cat SAEO (Special Application Engine Oil)

Note: Cat SAEO is for use in Caterpillar 3116 and 3126 Marine Diesel Engines with mechanical unit injection. This includes all 3116 and 3126 Marine Diesel Engines that begin with the following serial number prefixes: (S/N: 6SR), (S/N: 8NM), (S/N: 4KG), (S/N: 1SK), (S/N: 1ZJ), (S/N: 6MK) and (S/N: 4EZ).

The factory fill in 3116 and 3126 Marine Engines is Cat SAEO. The oil that is used for the factory fill has the following properties:

• API CF-4 classification

• Viscosity grade of SAE 30

For maximum performance in 3116 and 3126 Marine Diesel Engines with mechanical unit injection, Caterpillar recommends the following engine oil:

• Cat SAEO (SAE 30)

• Cat SAEO (SAE 40)

Commercial Oils (3116 and 3126 Marine Engines)

When Cat SAEO is not used, use the following commercial oils:

• Single grade oil with a viscosity of SAE 30 or SAE 40 with an API CF-4 classification is preferred.

• Single grade oil with a viscosity of SAE 30 or SAE 40 with a CF-4 or CG-4 additive package that does NOT contain viscosity improvers is an acceptable oil.

For an acceptable commercial single grade oil, contact your oil supplier or Caterpillar Customer Service:

The following explanation of the API CF-4 classification can be used to make the proper choice when a commercial single grade oil with API CF-4 classification is chosen.

API CF-4 - API CF-4 oils provide more stable oil control and reduced piston deposits in comparison to API CF and the obsolete CE and CD classifications of oil. API CF-4 oils provide improved soot dispersancy in comparison to API CF and obsolete CD oils. The API CF-4 classification was developed with a 0.40 percent sulfur diesel fuel. This represents the type of diesel fuels that are commonly available worldwide.

Some commercial oils that meet the API CF-4 classifications may require reduced oil change intervals. To determine the oil change interval, closely monitor the condition of the oil and perform a wear metal analysis. Caterpillar's S·O·S Oil Analysis program is the preferred method.

Total Base Number (TBN) and Fuel Sulfur Levels for Direct Injection (DI) Diesel Engines (3116 and 3126 Marine Engines)

The Total Base Number (TBN) for an oil depends on the fuel sulfur level. For direct injection engines that use distillate fuel, the minimum TBN must be 10 times the fuel sulfur level. The TBN is determined by the "ASTM D2896" procedure. The minimum TBN of the oil is 5 regardless of a low fuel sulfur level. Illustration 1 demonstrates the TBN.

Illustration 1	g00104890
(Y) TBN by "ASTM D2896" (X) Percentage of fuel sulfur by weight (1) TBN of new oil (2) Change the used oil when the TBN reaches this level.

Use the following guidelines for fuel sulfur levels that exceed 1.5 percent:

• Choose an oil with the highest TBN within the API CF-4 classification.

• Reduce the oil change interval. Base the oil change interval on the oil analysis. Ensure that the oil analysis includes the condition of the oil and a wear metal analysis.

Excessive piston deposits can be produced by an oil with a high TBN and/or high ash. These deposits can lead to a loss of control of the oil consumption and to the polishing of the cylinder bore.

Lubricant Viscosity Recommendations (3116 and 3126 Marine Engines)

The proper SAE viscosity grade of oil is determined by the minimum ambient temperature during cold engine start-up, and the maximum ambient temperature during engine operation.

Refer to Table 1 (minimum temperature) in order to determine the required oil viscosity for starting a cold engine.

Refer to Table 1 (maximum temperature) in order to select the oil viscosity for engine operation at the highest ambient temperature that is anticipated.

Generally, use the highest oil viscosity that is allowed for the ambient temperature at start-up.