803698 Mercury SCREW

Recommended Actions
Table 1
Troubleshooting Test Steps Values Results
1. Inspect the Electrical Connectors and the Wiring
A. Turn the main disconnect switch to the OFF position.
B. Thoroughly inspect the connectors. Refer to Troubleshooting, "Electrical Connectors-Inspect" for additional information.
C. Perform a 45 N (10 lb) pull test on the connector wires.
D. Check the harness for abrasions and pinch points.
Connectors and Wiring
Result: The connectors and wiring appear to be OK.
Proceed to Test Step 2.
Result: There is a problem with the connectors and/or wiring.
Repair: Repair or replace the connectors or wiring. Ensure that all the seals are properly in place and ensure that the connectors are coupled.
If the problem is not resolved, proceed to Test Step 2.
2. Check the Fuel Quality
A. Obtain a fuel analysis. The grade of the fuel affects the rate of fuel consumption. Refer to the engines Operation and Maintenance Manual for additional information.
B. Ensure that the fuel quality is not being affected by cold-weather conditions.
Fuel Quality
Result: The fuel quality is OK.
Proceed to Test Step 3.
Result: The fuel quality is NOT OK.
Repair: Replace the fuel.
If the problem is not resolved, proceed to Test Step 3.
3. Test the Fuel Injectors
A. Connect Cat® Electronic Technician (ET) to the service tool connector.
B. Use Cat ET to perform the following fuel injector tests:
- "Injector Solenoid Test"
- "Cylinder Cutout Test"
Refer to Troubleshooting, "Cat ET Service Features" for additional information.
Fuel Injectors
Result: The tests were successful.
Proceed to Test Step 4.
Result: The tests were not successful.
Repair: Diagnose the problem. Repair or replace damaged components.
If the problem is not resolved, proceed to Test Step 4.
4. Check for Proper Lubrication
A. Check for proper lubrication of the valve components. Check for sufficient lubrication between the injector tappets and the rocker arms.
B. Check for blocked oil passages. Oil passages must be clean. Refer to the Disassembly and Assembly manual for additional information.
C. Inspect the engine oil filters for ferrous material.
D. Obtain an S O S oil analysis. The analysis will contribute to a better understanding of oil contamination and the origin of the contamination.
Lubrication
Result: The oil passages are not blocked and the engine has proper lubrication.
Proceed to Test Step 5.
Result: The oil passages are blocked or the engine does not have proper lubrication.
Repair: Clean oil passages. Repair or replace damaged components.
If the problem is not resolved, proceed to Test Step 5.
5. Inspect the Valve Train Components
A. Remove the valve mechanism cover and the camshaft covers.
B. Check the valve lash. Refer to Testing and Adjusting, "Valve Lash - Adjust" for additional information.
C. Check the following valve train components for damage:
- Camshafts
- Valve rotocoils
- Valve springs
- Camshaft followers
- Rocker shafts
- Bridges
- Pushrods
- Injectors
D. Check for valves that do not move freely. Remove the cylinder head and inspect the valves. Refer to the Disassembly and Assembly manual for additional information.
Valve Train
Result: The valve train components are not damaged.
Proceed to Test Step 6.
Result: The valve train components are damaged.
Repair: Repair or replace damaged valve train components.
If the problem is not resolved, proceed to Test Step 6.
6. Inspect the Gear Train
A. Check the following gear train for damage:
- Crankshaft gear
- Camshaft drive gear
B. Verify that the crankshaft and the camshaft drive gears are set with the proper orientation for engine timing.
Gear Train
Result: The gear train has excessive wear.
Repair: Repair or replace damaged gear train components. Refer to the Disassembly and Assembly manual and the Reuse and Salvage Guidelines manual for additional information.
Verify that the repair eliminated the problem.
If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).