Pontiac 2004 GTO - Manual (Page 217)

Checking Coolant
The coolant surge tank is located in the engine
compartment on the driver’s side of the vehicle. See
Engine Compartment Overview on page 5-12 for more
information on location.
{ CAUTION:
Turning the surge tank pressure cap when the
engine and radiator are hot can allow steam
and scalding liquids to blow out and burn you
badly. Never turn the surge tank pressure
cap — even a little — when the engine and
radiator are hot.
The coolant level should be checked at least weekly, by
looking at the level on the coolant reservoir when the
engine is cold. The vehicle must be on a level surface.
When your engine is cold, the coolant level should
be at or slightly above the COLD FILL mark, at
the center weld joint. The level rises when the engine is
running and drops when the engine cools down. If
the level falls below the weld joint, the coolant should
be added to a little over the mark. Do not overfill,
as coolant requires space to expand when warmed up.
If the Low Coolant message on the trip computer
display comes on and stays on, it means you’re low on
engine coolant. You should check the level as soon
as possible. You may have to check the coolant level
when it is hot. See Engine Overheating on page 5-28.
5-27