MBE 4000 DDEC VI Troubleshooting – Section 14.9 Combustion Gases in Coolant

Section 14.9
Combustion Gases in Coolant

To determine if combustion gases in coolant is causing high engine coolant temperature, perform a cylinder compression test; refer to "2.2 Compression Pressure Test" .‪

1. If test results are to specifications; check radiator coolant flow; refer to "14.10 Abnormal Radiator Coolant Flow" .
2. If test results are not to specifications, refer to "14.9.1 Cylinder Head Gasket Replacement" .

Section 14.9.1
Cylinder Head Gasket Replacement

Perform the following steps to replace cylinder head gasket:‪

1. Remove and replace cylinder head gasket; refer to MBE 4000 Service Manual (6SE420), Chapter 1, Engine — Cylinder Head”.
2. Verify new cylinder head gasket replacement; refer to "14.9.1.1 Test Engine with Replaced Cylinder Head Gasket" .

Section 14.9.1.1
Test Engine with Replaced Cylinder Head Gasket

Perform the following to determine if cylinder head gasket 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 radiator coolant flow; refer to "14.10 Abnormal Radiator Coolant Flow" .