How to Check Oil Level

Starting in 2001, the C5 dipstick and tube were redesigned.
Although the official oil capacity of the engine is still 6.5 qts, most
owners report that it takes about 7 qts to get up to the ”Full” hole
on the new dipstick.
Personally, mine takes 6.9 qts. Also, the
new combination makes it very difficult to get an accurate dipstick
reading. Here are the techniques developed by Forum members to make the
readings easier:
1. Take out your dipstick, wipe it off, and sand
all 4 sides with 180 grit sandpaper, starting at the tip and going up as
far as the ”Z” bends in the stick. The scratches must go across the
stick so they will reduce the tendency of the oil to slide down the stick.
Carefully clean off the stick so you are not putting the abrasive grit
back into your engine!
2. Always park in the same level spot to
check your oil, because any tilt (fore/aft or left/right) can effect the
readings. If you want to be really anal about it, carry a small round
bubble level in your console so you can duplicate your favorite spot when
away from home.
3. Oil expands and contracts with temperature, so
try to check it at about the same oil temp each time, preferably after
your engine is fully warmed up.
4. When you shut down your engine
to check the oil, note the time on your watch. If you have a chronograph,
use the stopwatch feature. The convoluted oil pan on the C5 means that it
takes a long time for the oil to drain back into the pan, to the extent
that my Owner’s Manual says that checking the oil in the morning, even
though it is cold, will produce an falsely ”high” reading. I wait
exactly 15 minutes, waiting 10 minutes will give a slightly lower reading,
waiting 20 will give a slightly higher reading. 15 minutes seems right to
me, but the important thing is to use the same time every time.
5.
Immediately remove the dipstick, wipe it off, and put it in a clean place.
Personally, I wipe off the hood latch that is now level with my face, and
hang the stick in there. Just remember not to close the hood! Taking out
the stick allows the ”smeary” oil in the dipstick tube to drain
away.
6. Put the rag over the open dipstick tube while waiting for
the 15 minutes to go by.
7. At exactly 15 minutes, wipe off the
stick again (to remove any airborne dust) and check the oil level. You
should be able to get at least 2 checks before the oil smears up into the
tube and starts giving inconsistant readings.
This all sounds very
complicated, but after a couple of times it becomes second nature.
Enjoy!