To determine if faulty thermostats are causing high engine coolant temperature, perform the following:
- Remove thermostat from the thermostat housing, refer to MBE 4000 Service Manual (6SE420), Chapter 4”Cooling System — Thermostat”.
- Inspect thermostat for correct operation, refer to MBE 4000 Service Manual (6SE420), Chapter 4, “Cooling System — Thermostat”.
Perform the following steps to replace thermostats:
- Install new thermostat, refer to MBE 4000 Service Manual (6SE420), Chapter 4, “Cooling System — Thermostat”.
- Verify replaced thermostat; refer to "188.8.131.52 Test Engine with New Thermostat" .
Test Engine with New Thermostat
Perform the following steps to determine if thermostat replacement resolved high engine coolant temperature:
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.
- Start and run the engine.
- Run the engine through its operating range with no-load for approximately five minutes, allowing the engine coolant to reach normal operating range.
- If the engine coolant temperature is 82-105°C (180-221°F), no further troubleshooting is required. Shut down the engine.
- If the engine coolant temperature is not 82-105°C (180-221°F), shut down the engine. Check coolant pump; refer to "14.8 Faulty Coolant Pump" .
|EPA07 MBE 4000 DDEC VI Troubleshooting Guide - 6SE568|
|Generated on 10-13-2008|