Operators Manual

Table Of Contents
normal and caused by the velocity changes of the air flow within the air intake
plumbing. Electronic engines can actually deliver more fuel at lower engine speeds
than at rated speed.
The engine has been designed for a very quiet operation, but the air flow may be
noticeable to the tuned, attentive ear. The turbocharger operates at higher boost
pressure forcing EGR gas flow through the EGR plumbing. In some situations the
driver may believe he/she has experienced a charge air cooler system leak. Even
connecting trailer light and air hoses, the driver may hear a different tone (exhaust
and under hood with the engine idling.) If equipped with a turbo boost gauge, the
driver may occasionally note intake manifold pressure exceeds 35 psi (6.89 kPa).
Idling
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. 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 900 rpm should be enough to provide cab heat in above 0°C
(32°F) temperatures.
Detroit Diesel Electronic Controls (DDEC) System
76 All information subject to change without notice.
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