2007 Dodge Ram 3500 Pickup Owner Manual Diesel - Page 266

266 STARTING AND OPERATING Avoid Low Coolant Temperature Operation Continual operation at low coolant temperature below the normal range on the gauge (140°F/60°C) can be harmful to the engine. Low coolant temperature can cause incomplete combustion which allows carbon and varnish to form on piston rings and injector nozzles. Also, the unburned fuel can enter the crankcase, diluting the lubricating oil and causing rapid wear to the engine. Cooling System Tips - Automatic Transmission To reduce potential for engine and transmission overheating in high ambient temperature conditions, take the following actions: • City Driving - when stopped, put transmission in neutral and increase engine idle speed. • Highway Driving - reduce your speed. • Up Steep Hills - select a lower transmission gear, but try and keep the torque converter locked. • Air Conditioning - turn it off temporarily. Do Not Operate The Engine With Low Oil Pressure When the engine is at normal operating temperature, the minimum oil pressures required are: Idle 700 to 800 RPM ...10 psi (69 kPa) Full speed and load ...30 psi (207 kPa)