MBE 4000 DDEC VI Troubleshooting – Section 14.8 Faulty Coolant Pump

Section 14.8
Faulty Coolant Pump

To determine if a faulty coolant pump is causing high engine coolant temperature, perform the following:‪

1. Remove the coolant pump and inspect pump for failed shaft or rotor; refer to MBE 4000 Service Manual (6SE420), Chapter 4, “Cooling System — Coolant Pump”.
2. Replace coolant pump if damaged; refer to MBE 4000 Service Manual (6SE420), Chapter 4, “Cooling System — Coolant Pump”.

Section 14.8.1
Test Engine with Replaced coolant pump

Perform the following steps to determine if thermo-modulated fan replacement resolved high engine coolant temperature:‪

PERSONAL INJURY ‪
To avoid injury before starting and running the engine, ensure the vehicle is parked on a level surface, parking brake is set, and the wheels are blocked.‪

1. Start and run the engine.
2. Run the engine through its operating range with no-load for approximately five minutes, allowing the engine coolant to reach normal operating range.
   1. If the engine coolant temperature is 82-105°C (180-221°F), no further troubleshooting is required. Shut down the engine.
   2. If the engine coolant temperature is not 82-105°C (180-221°F), shut down the engine. Check combustion gases in coolant; refer to "14.9 Combustion Gases in Coolant" .