SERIES 60 ON-HIGHWAY ENGINE OPERATOR'S GUIDE Idling The common belief that idling a diesel engine causes no engine damage is wrong. Idling produces sulfuric acid, which breaks down the oil and eats into bearings, rings, valve stems and engine surfaces. If you must idle the engine for cab heat or cooling, the high idle function of the Cruise Control switches should be used. An idle speed of 1100 rpm should be enough to provide cab heat in above 32° F (0° C) ambients. Winter Fronts A winter front may be used to improve cab heating while idling. At least 25% of the grill opening should remain open in sectioned stripes that run perpendicular to the charge air cooler tube flow direction.
This assures even cooling across each tube and reduces header to tube stress and possible failure. Winter fronts should only be used when the ambient temperature remains below 10° F (-12.2° C). All information subject to change without notice. 39 DDC-SVC-MAN-0039 Copyright © 2009 DETROIT DIESEL CORPORATION