Pontiac 2003 Montana Owner's Manual page 345

What to Use
Use a mixture of one-half clean, drinkable water and
one-half DEX-COOL@ coolant which won't damage
aluminum parts. If you use this coolant mixture,
you
'
n't need
'
ad(' 'hing else.
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 wouldn't 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 DEX-COOL@ coolant.
If you have to add coolant more than four times a year,
have your dealer check your cooling system.
Notice: If you use the proper coolant, you don't
have t o add extra inhibitors or additives which claim
to improve the system. These can be harmful.
Notice: If you use an improper coolant mixture,
your engine could overheat and be badly damaged.
The repair cost wouldn't be covered by your
warranty. Too much water in the mixture can freeze
and crack the engine, radiator, heater core and
other parts.
Checking Coolant
The engine coolant
reservoir is located on the
driver's side of the
vehicle, above the engine
air cleaner/filter. 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 the FULL
COLD mark, or a little higher. When your engine is
warm, the level should be above the FULL COLD mark
or a little higher.
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