GMC 2007 Acadia Owner's Manual page 408

If coolant needs to be added more than four times
a year, have your dealer/retailer check the
cooling system.
Notice: If you use extra inhibitors and/or
additives in your vehicle's cooling system, you
could damage your vehicle. Use only the
proper mixture of the engine coolant listed in
this manual for the cooling system. See
Recommended Fluids and Lubricants on
page 511 for more information.
408
Checking Coolant
See Engine Compartment Overview on page 396
for more information on the location of the
coolant recovery tank.
The vehicle must be on a level surface when
checking the coolant level.
When the engine is cold, the coolant level should
be at the FULL COLD line or a little higher.
When the engine is warm, the level could be
above the FULL COLD level. The FULL COLD line
is marked on the coolant recovery tank.
The coolant recovery
tank cap has this
symbol on it.