1993 Buick Riviera Owner's Manual - Page 226

Engine Oil It's a good idea check your engine oil every time you to get fuel. In order to get an accurate reading, the oil must be warm and the vehicle must be on level ground. The engineoil dipstick.is directly behindthe engine fan.. 1 To Check Engine Oil: Pull out the dipstickandclean it with a paper towel or cloth, then push it back in all the way. Remove it again, ' I.ii' " .. , Turn off the engine and give theoil a few minutes to drain back into the oil pan. If you don't,the oil at dipstick might not show the When to Add Oil: If the oil is or below the ADD mark, then you'll need add someoil. But you must to actual level. of oil use tlwright kind. This section explains what kind to use. For crankcase capacity,see "Capacities and Specifications" in the Index.