Pontiac 2008 G6 - Manual (Page 269)

Adding Coolant
If you need more coolant, add the proper DEX-COOL ®
coolant mixture at the surge tank, but only when the
engine is cool. If the surge tank is empty, a special fill
procedure is necessary. See Engine Overheating
on page 5-33 and Cooling System on page 5-36.
{ CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol,
and it will burn if the engine parts are hot
enough. Do not spill coolant on a hot engine.
When replacing the pressure cap, make sure it is
hand-tight and fully seated.
Pressure Cap
Notice: If the pressure cap is not tightly installed,
coolant loss and possible engine damage may
occur. Be sure the cap is properly and tightly
secured.
See Engine Compartment Overview on page 5-14 for
more information on location.
Engine Overheating
There is an engine coolant temperature gage on your
vehicle’s instrument panel. See Engine Coolant
Temperature Gage on page 3-37.
5-33