825484 Mercury COVER-CYLINDER HEAD

Recommended Actions
Do not crank the engine continuously for more than 30 seconds. Allow the starting motor to cool for two minutes before cranking the engine again.
Note: The procedures have been listed in order of probability. Complete the procedures in order.
Table 1
Troubleshooting Test Steps Values Results
1. Diagnostic Codes
A. Download the Warranty Report and the Product Status Report with Histograms before performing any troubleshooting or clearing any diagnostic codes.
Note: The downloaded information will be required by the DSN if troubleshooting assistance is needed.
B. Use the electronic service tool to check for active or logged codes.
Diagnostic codes
Result: A diagnostic code is present.
Repair: Troubleshoot the code and then reset the histogram.
Result: A diagnostic code is not present.
Proceed to Test Step 2.
2. Visible Faults
A. Check that the fuel supply valve (if equipped) is in the OPEN position.
B. Check for the correct level of fuel, oil, and coolant.
C. Check for water in the primary fuel filter/water separator.
D. If the ambient temperature is below 0 °C (32 °F), check the specification of engine oil and oil for the machine.
E. Visually inspect the engine for the following faults:
Missing components
Damaged components
Damaged electrical cables or loose electrical cables
Oil leaks
Fuel leaks
All fuel filters are correctly installed.
F. Check that the battery voltage is correct.
G. Use the electronic service tool to check the average cranking speed of the engine.
Visible faults
Result: The fuel supply valve (if equipped) is not in the OPEN position.
Repair: Move the fuel supply valve to the OPEN position.
Result: The level of fuel, oil, or coolant is not correct.
Repair: Replenish any fluids with an incorrect level.
Result: Water is present in the primary fuel filter/water separator.
Repair: Drain any water from the primary fuel filter/water separator.
Result: The correct specification of engine oil and oil for the machine is not in use.
Repair: Replenish the system with oil of the correct specification for the ambient conditions.
Result: Battery voltage is low.
Repair: Check the batteries. Refer to Troubleshooting, "Battery Problem".
Result: The cranking speed is less than 150 rpm.
Repair: Investigate the cause of the low cranking speed and rectify, as necessary.
Note: The following step is only applicable to engines that have a Diesel Particulate Filter (DPF).
If the DPF frequently collects excessive soot prior to this fault, there may be a faulty cylinder in the engine. Proceed to Test Step 12.
Result: All checks are OK.
Proceed to Test Step 3.
3. Air Intake and Exhaust System
A. Check the air filter restriction indicator, if equipped.
B. Check the air intake and exhaust systems for the following defects:
Blockages
Restrictions
Damage to lines or hoses
Air and Exhaust System restrictions
Result: The air filter is restricted.
Repair: Replace the air filter.
Result: There are system restrictions.
Repair: Refer to Systems Operation/Testing and Adjusting, "Air Inlet and Exhaust System" for additional information on the air inlet and exhaust systems.
Result: The air intake and exhaust system is OK.
Proceed to Test Step 4.
4. Speed/Timing Sensors
A. Crank the engine and observe the engine speed on the electronic service tool status screen. Refer to Troubleshooting, "Speed/Timing - Test" for additional information.
Upon initial cranking, the status for engine speed may indicate that the engine speed signal is abnormal. This message will be replaced with an engine speed once the ECM is able to calculate a speed from the signal.
Speed/timing sensor
Result: The speed/timing sensors are not operating correctly.
Repair: Test the speed/timing sensors. Refer to Troubleshooting, "Speed/Timing - Test".
Result: The speed/timing sensors are operating correctly.
Proceed to Test Step 5.
5. Low-Pressure Fuel System
A. Visually check the fuel tank for fuel.
Note: The fuel gauge may be faulty.
B. If the temperature is below 0 °C (32 °F), check for solidified fuel (wax).
C. Check the primary filter/water separator for water in the fuel.
D. Check for fuel supply lines that are restricted or not correctly installed.
E. Replace the in-line fuel filter that is installed upstream of the Electric Fuel Lift Pump (EFLP).
F. Check that the EFLP is operating correctly.
G. Check for air in the fuel system and that the fuel system is primed.
H. Check the diesel fuel for contamination. Refer to Systems Operation, Testing, and Adjusting, "Fuel Quality - Test".
Low-pressure fuel system
Result: The fuel tank level is low.
Repair: Fill the fuel tank.
Result: The fuel contains solidified wax.
Repair: Replace the fuel with fuel of the correct specification for the ambient conditions.
Result: There are fuel supply lines that are restricted or not correctly installed.
Repair: Install the fuel lines correctly. Replace any damaged or restricted fuel lines.
Replace the primary fuel filter and the secondary fuel filters. Refer to the Operation and Maintenance Manual for further information.
Result: The EFLP is not operating correctly.
Repair: Investigate the fault with the EFLP. Refer to Troubleshooting, "Fuel Transfer Pump - Test".
Result: There is air in the fuel system.
Repair: Prime the fuel system. Refer to Systems Operation, Testing, and Adjusting, "Fuel System - Prime".
Result: The diesel fuel is contaminated.
Repair: Drain the fuel tank and the fuel system.
Replace the primary fuel filter and the secondary fuel filters. Refer to the Operation and Maintenance Manual for further information.
Fill and prime the fuel system with fuel of the correct specification. Refer to Systems Operation, Testing, and Adjusting, "Fuel System - Prime".
Result: The low-pressure fuel system is OK.
Proceed to Test Step 6.
Illustration 1 g03700009
Transfer Pump Inlet Regulator (TPIR) components on a C4.4 engine
(1) Transfer Pump Inlet Regulator (TPIR)
(2) TPIR return port
Illustration 2 g06100802
Transfer Pump Inlet Regulator (TPIR) components on a C6.6 engine
(1) Transfer Pump Inlet Regulator (TPIR)
(2) TPIR return port
Illustration 3