Gen 5 DD Platform Operators Manual Idling the Engine The common belief that idling a diesel engine causes no engine damage is wrong. Idling produces sulfuric acid, which is absorbed by the lubricating oil and eats into bearings, rings, valve stems and engine surfaces. During long engine idling periods, the engine coolant temperature may fall below the normal operating range. The incomplete combustion of fuel in a cold engine will cause crankcase oil dilution, formation of lacquer or gummy deposits on the valves, pistons, and rings, and rapid accumulation of sludge in the engine.
If the operator must idle the engine for cab heat or cooling, the high idle function of the cruise control switches should be used. For more information on high idle using the cruise control switches, Refer to section "Detroit Diesel Electronic Control System Features". An idle speed of 900 rpm should be enough to provide cab heat in above 0°C (32°F) temperatures. Never allow the engine to idle for more than 30 minutes. When prolonged idling is necessary, maintain an engine speed of 900 rpm. Running the Engine While the engine is operating, monitor the battery charge indicator and the oil pressure. Unnecessary idling should be avoided whenever possible.
Checking the Oil Pressure Monitor the oil pressure as follows: 1. Observe the oil pressure gauge immediately after starting the engine. An oil pressure gauge that registers 50 psi (3.4 bar) is a good indicator that all moving parts are getting lubrication. The engine oil pressure operating ranges for Detroit™ Gen 5 Heavy Duty engines are listed in the table below. 2. If low oil pressure is indicated contact an authorized Detroit™ service outlet for further instructions. Table 2. Warming up the Engine Run the engine at part throttle for about five minutes to allow it to warm up before applying a load. All information subject to change without notice.
27 DDC-SVC-MAN-0217 Copyright © 2022 DETROIT DIESEL CORPORATION Oil Pressure Operating Ranges 50 psi (3.4 bar) Normal Oil Pressure 25 psi (1.7 bar) Low Oil Pressure 0 psi (0 bar) Very Low Oil Pressure