GMC 2007 Sierra - Manual (Page 505)

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. See Cooling
System on page 508.
{ 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.
Coolant Surge Tank 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.
The coolant surge tank pressure cap must be fully
installed on the coolant surge tank. See Engine
Compartment Overview on page 480 for more
information on location.
Engine Overheating
You will find a coolant temperature gage on your
vehicle’s instrument panel. See Engine Coolant
Temperature Gage on page 256.
In addition, you will find an ENGINE
OVERHEATED and a REDUCED ENGINE
POWER message in the Driver Information
Center (DIC) on the instrument panel. See DIC
Warnings and Messages on page 270.
505