Buick 2003 Rendezvous Owner's Manual page 341

How to Add Coolant to the Coolant
Recovery Tank
If you haven't found a problem yet, but the coolant level
isn't at or above the FULL COLD mark, add a 50/50
mixture of clean, drinkable water and DEX-COOL@
engine coolant at the coolant recovery tank. See Engine
Coolant on page 5-22 for more information.
Adding on11
.
llain water to ur cot 1g
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.
I
Notice:
In cold weather, water can freeze and crack
the engine, radiator, heater core and other parts.
Use the recommended coolant and the proper
coolant mixture.
You can be Durned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol
and it will burn if the engine parts are hot
enough. Don't spill coolant on a hot engine.
I
5-30