2006 Dodge Ram 3500 Pickup Owner Manual Diesel - Page 262

262 STARTING AND OPERATING If temperatures are below 32°F (0°C), operate the engine at moderate speeds for 5 minutes before full loads are applied. Engine Idling - In Cold Weather Avoid prolonged idling in ambient temperatures below 0°F. Long periods of idling may be harmful to your engine because combustion chamber temperatures can drop so low that the fuel may not burn completely. Incomplete combustion allows carbon and varnish to form on piston rings and injector nozzles. Also, the unburned fuel can enter the crankcase, diluting the oil and causing rapid wear to the engine. NOTE: An optional driver-controlled high idle speed is available on automatic transmission equipped vehicles with speed control. This feature allows the driver to select an elevated idle speed between 1100 and 1500 rpms. Your dealer can enable this feature. NOTE: • If ambient temperatures are low and the coolant temperature is below 200°F (93°C), the engine idle speed will slowly increase to 1000 RPM after 2 minutes of idle, if the following conditions are met: • foot is off brake pedal and throttle pedal • automatic transmission is in Park (P) • vehicle speed is zero • Applying the throttle will cancel fast idle • If the engine is equipped with an aftermarket exhaust brake (manual transmissions only), operating the exhaust brake at idle will greatly improve warm up rate and will help keep the engine close to operating temperature during extended idle.