GMC 2003 Savana Van Owner's Manual page 258

When to Add Engine Oil
If the oil is at or below the ADD mark, then you'll need
to add at least one quart of oil. But you must use
the right kind. This part explains what kind of oil to use.
For engine oil crankcase capacity, see Capacities
and Specifications on page 5- 103.
Notice: Don't add too much oil. If your engine has
so much oil that the oil level gets above the
upper mark that shows the proper operating range,
your engine could be damaged.
The engine oil filler cap is
located between the
coolant recovery tank and
the engine air cleaner/filter.
See Engine Compartment
Overview on page 5- 12
for more information
on location.
Be sure to fill it enough to put the level somewhere in
the proper operating range. Push the dipstick all the way
back in when you're through.
5-1 5