1994 Cadillac Seville Owner's Manual - Page 332

The Northstar engine is designed to minimize the need for routine maintenance while incorporating systems to remind the driver when service isrequired. An oil life indexindicator monitors ongoing operating conditions and reminds the driver whenan oil change is needed. A low coolant warning messagekeeps track of the level of this vital fluid.Direct acting hydraulictappets provide maintenance free zerolash operation of the 32 valves from idle to the6500 rpm redline.The camshafts are driven to by a two stage roller chain assembly which is designed provide quiet maintenance free operation. Platinum tipped spark plugs increase the replacement interval to 100,OO miles. The fourvalves per cylinder design provides more efficient engine breathing, resulting in higher power than comparable two valve engines. The induction system usessmooth thermoplastic tubes to channel air into the cylinders. These smooth tubes simulate the elaborateport polishing methods used on racing engines.The shape and length of the tubes boosts horsepower by using sonicpressure waves created by the motion of the inlet valves to increase the amount of air entering each cylinder. Once the intake charge has entered thecylinder, the centrally located spark plug ensures fast and efficient burning of the fuel/air mixture. This engine is designedto be very durable. The aluminum block has cast-in-place iron cylinder liners for greater wear resistance. High bronze strength connecting rods support the free floating piston pins in bushings for superior high speed performance. The fillets of the nodular iron crankshaft undergo a highpressure compression rollingoperation to improve their resistance to fatigue. Quiet operationis enhanced by the use of special materials and designs. The frontcover of the engine is stamped from laminated steel which damps out noise. Special cam cover gasket seals isolate va1v.e train operation. The fuel injectors are placed insidethe induction system housing to eliminate the clicking noise which common to otherfuel is injected engines. The Northstarengine is designedto provide years of efficient, reliable, satisfying operation. 319