Re: Short running period with engine
Reply #8 –
Jim,
You may be confusing the generic term "fast idle" with the diesel engine rating term "High Idle".
When most owners say "fast idle", they mean any idle speed above the "normal" idle. Most of our coaches have some means of increasing the idle to a higher RPM than normal, such as using the cruise control. This is usually done to speed the engine warmup, or to speed getting the air system up to cutout pressure, etc.
"High Idle" on the other hand is a technical term applied to diesel engines. In the case of my C8.3 for instance, the "High Idle" speed is rated at 2760 RPM. The way I understand it, this is the max engine speed which would be attained with the throttle held wide open and NO load on the engine...like if you mashed the throttle to the floor with the transmission in neutral. Supposedly the engine is designed to achieve this speed and stay in one piece...but I don't think I want to test this fact with my coach.