804179 Mercury SCREW

Accessory Equipment
Isolate the source of the noise.Internal Engine Components
Valve train components
Pistons
Crankshaft
Gear trainRecommended Actions
Table 1
Troubleshooting Test Steps Values Results
1. Isolate the Source of the Noise
A. If the source of the noise is the engine accessory, remove the suspect engine accessory. Inspect the suspect engine accessory.
Engine accessory
Result An engine accessory is not the source of the noise.
Repair: Proceed to Test Step 2.
Result An engine accessory is the source of the noise.
Repair: Repair the engine accessory and/or replace the engine accessory, if necessary.
If the problem is not resolved, proceed to Test Step 2.
Illustration 1 g06136378
Table 2
Troubleshooting Test Steps Values Results
2. Check for Debris on the High-Pressure Fuel Pump Drain Plug
Note: These engine have been built with high-pressure fuel pumps that have a wet sump and contain approximately 900 mL (30.5 oz) of engine oil. Have a suitable container available when removing the drain plug. Use the automatic pre-lube cycle to refill the sump prior to starting the engine.
A. Turn the engine to OFF.
B. If equipped, remove drain plug (1) from the high-pressure fuel pump.
If not equipped, remove drain plug (2) from the fuel pump adapter.
The engine oil should drain from the opening. Check the magnetic plug for excessive debris. Clean the plug prior to reinstallation.
Excessive debris
Results: There was not excessive debris on the magnetic plug. Reinstall the oil drain plug.
Proceed to Test Step 3.
Results: There is a continuous stream of fuel flowing from the drain hole and/or there is excessive debris on the plug..
Repair: Replace the high-pressure fuel pump.
Replace the in-line high-pressure fuel filter element in the block assembly that is part of the front fuel injection line.
If the problem is not resolved, proceed to Test Step 3.
3. Inspect the Gear Train
A. Inspect the gear train and lower end components.
Gear train
Results: The gear train is OK.
Proceed to Test Step 4.
Results: The gear train is NOT OK.
Repair: Repair or replace any damaged parts. Verify that the repair eliminated the problem.
If the problem is not resolved, proceed to Test Step 4.
4. Inspect the Valve Train Components
A. Remove the valve mechanism cover and the camshaft covers.
B. Check the following items for damage:
- Camshaft
- Valve springs
- Lifters
- Pushrods
- Bridges
C. Refer to the Disassembly and Assembly for additional information.
D. Thoroughly clean the valve train components. Ensure that all of the valves move freely. Replace any damaged parts.
E. During engine operation at rated speed, the valve rotation can be observed and measured.
Valve train
Results: The valve train components are not damaged.
Repair: Proceed to Test Step 5.
Results: The valve train components are damaged.
Repair: Repair the engine components and/or replace the engine components, if necessary.
If the problem is not resolved, proceed to Test Step 5.
5. Inspect the pistons for damage and wear.
Pistons
Results: The pistons are OK.
Repair: Proceed to Test Step 6.
Results: The pistons are NOT OK.
Repair: Perform the necessary repairs or replace.
If the problem is not resolved, proceed to Test Step 6.
6. Inspect the Crankshaft
A. Inspect the crankshaft and the related components. Look for worn thrust plates and wear on the crankshaft.
B. Inspect the connecting rod bearings and the bearing surfaces on the crankshaft. Make sure that the bearings are in the correct position.
C. Check the counterweight bolts.
Crankshaft
Result: The crankshaft or the related components are damaged or worn.
Repair: Repair or replace any damaged parts. Verify that the repair eliminated the problem.