12620 1 Mercury GASKET, Cover, Non Oil Injection

Probable Causes
Engine Derate or High Altitude Operation
Check for active engine deratesElectrical Connections
Improperly connected electrical connectionsDiagnostic Codes
Check for intermittent diagnostic codesThrottle Signal
Intermittent throttle signalFuel System
Fuel system componentsFuel Supply
Fuel supply pressureAir Inlet and Exhaust System
Restriction in the air inlet and exhaust system
Excessive temperature of the turbocharger that causes engine derateFlash File
Verify that the latest flash file has been installed in the engine Electronic Control Module (ECM).Recommended Actions
Note: If the problem only occurs under certain conditions, test the engine under those conditions. Examples of certain conditions are high engine speed, full load, and engine operating temperature. Troubleshooting the symptoms under other conditions can give misleading results.Perform the following procedures in the order that is provided.Check for Engine Derates and High Altitude Operation
Connect Caterpillar Electronic Technician (ET) and check for logged events that derate engine power. An engine derate indicator will appear on Cat ET while an active engine derate is occurring.The following conditions may cause an engine derate that is not annunciated to the operator.The ECM monitors the following parameters in order to calculate a value for the exhaust temperature of the engine:
Intake manifold air temperature
Turbocharger compressor inlet pressures
Engine speedHigh intake manifold air temperature, high altitude operation, and/or high engine speeds at high load can cause the exhaust temperature to increase. These temperatures may raise to a level that will damage the components of the exhaust system. If the conditions warrant, the ECM may derate the engine power in order to prevent high calculated temperatures. This engine derate will help avoid potential damage to these engine components.During an engine derate that is initiated for this calculated temperature, two histograms will begin recording data. Data will be recorded for intake manifold air temperatures and turbocharger compressor inlet air pressures. The histogram data will be recorded by the ECM only while the engine is being derated. View this histogram data in order to assist in troubleshooting low-power complaints.Perform the following procedure:
Determine the operating conditions of the engine. Interview the operator, when possible. Determine if the engine is operating at a high altitude while the engine is derated. If the engine derate is due to normal engine operation, review the histograms for intake manifold air temperatures and turbocharger compressor inlet air pressures. The histograms will assist in determining the reason why the engine is being derated.
Check the Air-to-Air Aftercooler (ATAAC) for debris. The intake manifold air temperature will increase if the ATAAC is obstructed. Check the fins of the ATAAC for obstructions. If the fins of the ATAAC are obstructed, clear the obstruction. Return the engine to service.Electrical Connections
Verify that the following connectors are installed correctly:
ECM connectors
Connectors for the wiring harness under the valve cover
Engine speed/timing sensor connectorsRefer toTroubleshooting, "Electrical Connectors - Inspect" for the proper troubleshooting procedure.Check for Intermittent Diagnostic Codes
Certain diagnostic codes may cause poor performance. Connect Cat ET and check for active codes and/or for logged codes. Troubleshoot any codes that are present before continuing with this procedure.Intermittent Throttle Signal
Monitor the status for "Throttle Position" on Cat ET. Verify that the status for "Throttle Position" is stable and that the engine is able to reach high idle speed. Perform the necessary repairs.Fuel System
Ensure that the fuel system is operating properly.
Start the engine.
Access the "Cylinder Cutout Test" in the "Diagnostic Tests" under the "Diagnostics" menu.
Select the "Automatic Cylinder Cutout Test" on Cat ET.
Perform the test. Diagnose the problem and then repair any cylinders that fail the "Cylinder Cutout Test" before continuing with this procedure. Clear all logged diagnostic codes. Verify that the repair has eliminated the problem in the cylinder.Fuel Supply Pressure
Check the fuel pressure. Ensure that the fuel pressure is stable. Refer to Systems Operation/Testing and Adjusting for the procedure that is used to check the fuel pressure using a gauge.
Visually check the fuel level. Do not rely on the fuel gauge only. If necessary, add fuel. If the engine is run out of fuel, use the fuel priming pump to purge the air from the fuel system.
Ensure that the fuel supply valve (if equipped) has been fully opened.
Check the fuel lines for the following problems: restrictions, collapsed lines, pinched lines and loose connections. If problems are found with the fuel lines, repair the lines and/or replace the lines.
Prime the fuel system if any of the following procedures have been performed:
Fuel filter replacement
Service on the low-pressure fuel supply circuit
Unit injector replacement
Check the fuel tank for foreign objects which may block the fuel supply.
Check the fuel filters for plugging.
Check the fuel quality. Ensure that the fuel meets the requirements of Operation and Maintenance Manual, SEBU6250, "Caterpillar Machine Fluids Recommendations ". Cold weather adversely affects the characteristics of the fuel. Refer to the Operation and Maintenance Manual for information on improving the characteristics of the fuel during cold-weather operation.Restriction in the Air Inlet and Exhaust System
Ensure that the turbocharger is operating correctly. Periodic inspection and cleaning are recommended for the turbocharger compressor housing. Refer to Systems Operation/Testing and Adjusting for the procedure to inspect the turbocharger.Check the air filter restriction indicator. Clean plugged air filters or replace plugged air filters.Check the air inlet and exhaust system for restrictions and/or leaks. Refer to Systems Operation/Testing and Adjusting for the procedure to inspect the air inlet and exhaust system.Flash File
Check SIS Web for the latest version of the engine flash file. Verify that the latest flash file has been installed.