2000 Saab 9-5 Owner's Manual - Page 170

170 Car care and technical information ORVR (Onboard Refueling Vapor Recovery) Hydrocarbon vapors formed when refueling will be recovered by the car and not released into the atmosphere. The hydrocarbons are absorbed in a evaporative emission canister. When the engine is subsequently started, the evaporative emission canister is gradually purged as air is sucked into it through a shut-off valve. The hydrocarbon/air mixture passes through the evap canister purge valve and into the engine where it is burned. When refueling, make sure you screw the filler cap on and keep turning until it has clicked at least 3 times. Otherwise, it is possible for the CHECK ENGINE light to illuminate and a "TIGHTEN FUEL FILLER CAP" message to appear on SID. Refueling, see page 134. Engine 2.3-liter engine The 2.3-liter model is a transverse, 4-cylinder in-line engine with twin overhead camshafts and 4 valves per cylinder. This engine is equipped with balance shafts that reduce engine vibration to a minimum. The balance shafts are chain driven and rotate at twice the speed of the crankshaft. They produce forces and torques that are opposed to those generated by the pistons and connecting rods, an effect that occurs twice for each revolution of the engine. Engine noise is also reduced as the counter-rotating shafts counteract the vibration from the moving parts of the engine. The transmission, located on the right (viewed from the front), is integrated with the engine. All models have front-wheel drive. Balance shafts, 4-cyl. engine 3.0-liter V6 engine The 3.0-liter engine is a transverse, V6 engine with each bank of cylinders having double overhead camshafts and 4 valves per cylinder. The transmission, located on the right (viewed from the front), is integrated with the engine. All models have front-wheel drive. IB601