Frequently Asked Questions about Oil Emulsion{1000, 1317, 1348} Caterpillar

On-Highway Engine:

C13 (S/N: LEE1-UP)

C15 (S/N: SDP1-UP)

Introduction

The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.

What is Oil Emulsion?

• Oil emulsion, defined as a thick mixture of engine oil and crankcase moisture that adheres to internal engine surfaces. Modern Engine oil formulations have a tendency to form a thick emulsion as water condenses on the relatively cool internal engine components. This condensing action is similar to the "sweating" that occurs with a cold drink on a hot humid day, and is not an indicator of a coolant leak.

• This oil emulsion will typically dissipate as the engine reaches normal operating temperatures, causing no operational problems. Certain conditions such as frequent start/stops, cold weather, light load operation and/or cooling system issues (overcooling) can increase the emulsion accumulation.

• The emulsion will not typically cause operational problems, unless it accumulates to the point that it plugs the Open Crankcase Ventilation (OCV) filter systems. Advanced stages of oil emulsion may trigger the check engine light and derate the engine due to a plugged OCV filter element.

Why is Emulsion Inside the Engine?

• Environmental conditions such as ambient temperature and relative humidity drastically impact emulsion formation. Data suggest that ambient temperatures between 0.55 °C (33 °F) and 7.22 °C (45 °F) will increase potential for emulsion formation.

• Chassis variables including high under-hood airflow, low engine load, and overcooling affect the level of oil emulsion formed in the engine.

• Inside past engine models, water (formed as a natural by-product of normal diesel combustion) exited the engine through the draft tube as a component of blow-by gas. The same is true for 2007 engines, but restrictions to flow in the crankcase ventilation system slow the flow of hot gases allowing them to cool and condense on cool engine components

What to look for in Engine Overcooling:

• In general, 2007 Model Year Heavy Duty Engines have a normal operating coolant temperature range between 82 °C (180 °F) to 98 °C (210 °F). Engines under load that average coolant temperatures below 82 °C (180 °F) may have an overcooling issue caused by thermostat malfunction, improper vent line routing, auxiliary radiator sources, or auxiliary devices connected to the cooling system that are not engineered to the specific chassis/engine combination (i.e. auxiliary power units plumbed to the chassis cooling system).

• Extended operation while overcooling will cause accelerated wear.

• Please consult the local Caterpillar Dealer if there is concern about potential overcooling.

Does the Engine have Coolant in the Oil?

• Engines with oil emulsion will have a buildup of gray, oily residue on some engine components like the oil fill tube and the dipstick tube but this does not indicate coolant in the oil. Engine oil lubrication qualities are not affected.

• Engines with an internal coolant leak will lose coolant from the cooling system or radiator. The coolant may also show signs of oil contamination. Engine oils that contain a small to moderate amount of coolant will not show any visual signs of coolant contamination. Engine oils with suspected coolant contamination should be verified by normal engine oil analysis.

• 2007 Model Year Engines may experience higher levels of Potassium (K) and Aluminum (Al) for the first 3-4 oil change intervals. Moisture in the inlet air reacts with the coating of brazed joints on the precooler. This is a normal condition for 2007 Model Year Engines and also does not indicate coolant in the engine oil.

What are the effects of Oil Emulsion?

• Engines with emulsion formation may illuminate the check engine light and log an associated fault code in the electronic control module due to a plugged OCV filter.

• Oil emulsion may accumulate inside the oil fill tube, oil level gauge tube, crankcase ventilation system, and under the valve cover.

• Some engines with emulsion, stopped for extended periods, may exhibit a thin layer of corrosion on top of the variable valve actuators. This condition will not cause any subsequent wear or failures to the engine.

What are the Long Term effects of Oil Emulsion Inside the Engine?

• None. The emulsion should disappear with normal engine operating temperatures 82 °C (180 °F) to 98 °C (210 °F). Engine oil lubrication qualities are not effected. Test results and engine teardown inspections to-date, show the presence of emulsion to have no negative effect to life of engine oil, bearings or other major engine components.

How is Caterpillar going to Eliminate Emulsion Formation?

• Caterpillar is developing an improved OCV canister, filter element, crankcase breather housing and hoses. The new parts will retain the emission compliance of the system and strip water from the blow-by gases. Engine derates and plugged OCV filters will be drastically reduced. These changes will extend the OCV filter life to the recommended change interval that will be found in the Operation and Maintenance Manual. Caterpillar will announce the availability of the changes discussed above.

• The improvements referenced above will not eliminate emulsion from the crankcase in all cases. Operators or Maintenance Personnel may still see slight emulsion on the oil level gauge tube, oil fill tube, and the underside of the valve cover. This condition is normal. Engine life will not be affected.

What to do if an engine has Emulsion Formation?

• Caterpillar Dealers will have the latest service information pertaining to oil emulsion and current updates. Please contact the local Caterpillar Dealer for service.