2005 Saab 9-5 Owner's Manual - Page 188

186 Car care and technical information 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. Engine oil Checking the oil level Check the engine-oil level regularly. This should be done after the engine has been run to normal temperature and then allowed to cool for 2-5 minutes, with the car standing on level ground. Remove the dipstick and wipe it clean before checking the level. The oil level must not be allowed to drop below the MIN mark on the dipstick, nor should oil be filled beyond the MAX mark, as this can lead to excessive oil consumption. The distance between the MIN and MAX marks on the dipstick corresponds to a volume of approximately 1.05 qts (1 liter). When necessary, add oil of the recommended grade via the dipstick tube. Balance shafts The transmission, located on the right (viewed from the front), is integrated with the engine. All models have front-wheel drive. IB601