Hummer 2006 H3 - Manual (Page 297)

What to Use
Use a mixture of one-half clean, drinkable water and
one-half DEX-COOL
® coolant which will not damage
aluminum parts. If you use this coolant mixture, you
do not need to add anything else.
{ CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil
before the proper coolant mixture will. Your
vehicle’s coolant warning system is set for the
proper coolant mixture. With plain water or the
wrong mixture, your engine could get too hot
but you would not get the overheat warning.
Your engine could catch fire and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and the proper coolant.
Notice: If you use an improper coolant mixture, your
engine could overheat and be badly damaged. The
repair cost would not be covered by your warranty.
Too much water in the mixture can freeze and crack
the engine, radiator, heater core, and other parts.
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 6-12 for more information.
Checking Coolant
The coolant recovery tank
cap has this symbol on it.
It is located toward the
rear of the engine
compartment on the
passenger’s side of the
vehicle. See Engine
Compartment Overview
on page 5-12 for more
information on location.
The vehicle must be on a level surface. When your
engine is cold, the coolant level should be at FULL
COLD, or a little higher. When your engine is warm,
the level could be above the FULL COLD level.
5-25