Michael 
2003 Nissan Sentra Sedan XE 4dr Sedan (1.8L 4cyl 5M)
Sentra quality down
 This engine was leaking antifreeze in the engine.  We needed a new headgasket.It was covered under warranty but we had to fight to get the Nissan dealer to fix it.  The engine has suffered damage from the coolant leak.  It takes longer than usual to start.  Also during an oil change, the dealer tech noticed we were losing alot of oil through the crankshaft oil seal.  also replaced during warranty.  This with a car with only 18k miles at the time.   I would avoid this car with the 1.8 L engine. I've talked with others who own this car/engine.  they had the same problems! Sentras are made in Mexico.  buyer beware.