Ford Grand Marquis Owner's Manual page 211

Checking and Adding Engine Oil
Since the proper amount of engine oil is
important for safe engine operation, check the oil
using the dipstick each time you put fuel in
your vehicle. Remember the engine must be off,
the oil must be warm and the vehicle must be
parked on level ground.
Checking the engine oil level:
1. Turn the engine off after it has warmed up
and allow a few minutes for the engine oil
to drain back into the oil pan.
2. Set the parking brake, making sure the
gearshift is securely latched in P (Park).
3. Open the hood. Protect yourself from engine
heat.
4. Locate the engine oil dipstick (highlighted in
yellow) and carefully pull it out of the
engine.
5. Wipe the dipstick clean and put it back into
position, making sure it is fully seated.
Engine oil dipstick
6. Carefully pull the dipstick out again. If the
oil level is below the "ADD 1 QT" line, add
engine oil as necessary. If the oil level is
beyond the letter "F" in Full, engine damage
or high oil consumption may occur and
some oil must be removed from the engine.
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