Instruments Coolant Temperature Gauge Engine Oil Pressure Gauge NOTICE NOTICE A sudden increase in coolant temperature may indicate engine or cooling system failure. Bring the vehicle to a safe stop and investigate the cause to prevent further damage. Do not operate the engine until the cause has been determined and corrected. A sudden decrease or absence of oil pressure may indicate mechanical failure. Bring the vehicle to a safe stop and investigate the cause to pre- vent further damage. Do not operate the engine until the cause has been determined and cor- rected. During normal engine operation, the coolant tem- perature gauge ( Fig. 3.1 ) should read between 175 and 195°F (79 and 91°C).
If the temperature remains below 160°F (71°C) or exceeds the maximum tem- perature shown in Table 3.2 , inspect the cooling sys- tem to determine the cause. The engine oil pressure gauge ( Fig. 3.2 ) displays the current engine oil pressure. If engine oil pressure falls below the minimum levels shown in Table 3.3 , the CHECK engine lamp will illuminate. If the condi- tion does not improve, the STOP engine lamp will illuminate and an audible warning will sound. The engine will then derate or shut down, depending on the type of engine protection system installed. If coolant temperature rises above the maximum temperature listed in Table 3.2 , the CHECK engine lamp will illuminate.
If the condition does not im- prove, the STOP engine lamp will illuminate and an audible warning will sound. The engine will then der- ate or shut down, depending on the type of engine protection system installed. 05/14/2001 f610537 Fig. 3.2, Engine Oil Pressure Gauge Minimum Oil Pressure * Engine Model At Idle Speed: psi (kPa) At Rated RPM: psi (kPa) Caterpillar 10–20 (69–138) 30–45 (207–310) Cummins 15 (103) 35 (241) Detroit Diesel 14 (97) 55 (350) Mercedes-Benz 7 (50) 36 (250) 05/11/2001 f610535 Fig. 3.1, Coolant Temperature Gauge Maximum Coolant Temperature Engine Make Temperature:
°F (°C) Caterpillar 215 (101) Cummins 225 (107) Detroit Diesel 215 (101) Mercedes-Benz 203 (95) * Pressures apply with the engine at operating temperature. Oil pressure may be higher on a cold engine. Observe and record pressures when the engine is new to create a guide for checking engine condition. Table 3.3, Minimum Oil Pressure Table 3.2, Maximum Coolant Temperature 3.4