1998 Buick Skylark Owner's Manual - Page 237

When to Add Engine Oil If the oil is at or below the ADD line, then you'll need to addat least one quartof oil. But you must use the of right kind.This part explains what kind oil to use.For crankcase capacity,see "Capacities and Specifications" in the Index. I NOTICE: ~ ~~ Don't add too much oil. your engine has If so much oil that theoil level gets above the upper mark that shows the proper operating range, your engine could be damaged. 2.4L Engine The engine oil cap onthe 2.4L engine is located on fill the left side of the engineby the coolant surge tank.