2007 BUICK RANDEZVOUS engine

Notice:If your engine catches re because
you keep driving with no coolant, your vehicle
can be badly damaged. The costly repairs
would not be covered by your warranty. See
Overheated Engine Protection Operating Mode
on page 380for information on driving to a
safe place in an emergency.
If No Steam Is Coming From Your
Engine
If you get an engine overheat warning but see or
hear no steam, the problem may not be too serious.
Sometimes the engine can get a little too hot
when you:
Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.
Tow a trailer.If you get the overheat warning with no sign of
steam, try this for a minute or so:
1. If the air conditioner is on, turn it off.
2. Turn on the heater to full hot at the highest fan
speed and open the windows as necessary.
3. If you are in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving — DRIVE (D).
If the vehicle no longer has the overheat warning,
you can drive. Just to be safe, drive slower for
about 10 minutes. If the warning does not
come back on, you can drive normally.
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If the warning continues, pull over, stop, and park
your vehicle right away.
If there is still no sign of steam, idle the engine for
three minutes while you are parked. If vehicle still
has the warning, turn off the engine and get
everyone out of the vehicle until it cools down.
Also, see “Overheated Engine Protection
Operating Mode” later in this section.
You may decide not to lift the hood but to get
service help right away.Overheated Engine Protection
Operating Mode
This emergency operating mode lets your vehicle
be driven to a safe place in an emergency situation.
If an overheated engine condition exists, an
overheat protection mode which alternates ring
groups of cylinders helps prevent engine damage.
In this mode, there is a signicant loss in power
and engine performance. The temperature gage
indicates an overheat condition exists. Driving
extended miles (km) and/or towing a trailer in the
overheat protection mode should be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine
damage, allow the engine to cool before
attempting any repair. The engine oil will be
severely degraded. Repair the cause of coolant
loss, change the oil and reset the oil life
system. SeeEngine Oil on page 365.
380

Cooling System
When you decide it is safe to lift the hood, this is
what you see:
A. Radiator Pressure Cap
B. Electric Engine Cooling Fans
C. Engine Coolant Recovery Tank{CAUTION:
An electric engine cooling fan under the
hood can start up even when the engine
is not running and can injure you. Keep
hands, clothing, and tools away from any
underhood electric fan.
If the coolant inside the coolant recovery tank is
boiling, do not do anything else until it cools down.
The vehicle should be parked on a level surface.
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The coolant level should be at or above the full
cold mark. If it is not, you may have a leak at the
pressure cap or in the radiator hoses, heater hoses,
radiator, water pump, or somewhere else in the
cooling system.
{CAUTION:
Heater and radiator hoses, and other
engine parts, can be very hot. Do not
touch them. If you do, you can be burned.
Do not run the engine if there is a leak.
If you run the engine, it could lose all
coolant. That could cause an engine re,
and you could be burned. Get any leak
xed before you drive the vehicle.If there seems to be no leak, with the engine on,
check to see if the electric engine cooling fans
are running. If the engine is overheating, both fans
should be running. If they are not, your vehicle
needs service.
Notice:Engine damage from running your
engine without coolant is not covered by your
warranty. SeeOverheated Engine Protection
Operating Mode on page 380for information on
driving to a safe place in an emergency.
Notice:Using coolant other than DEX-COOL
®
may cause premature engine, heater core, or
radiator corrosion. In addition, the engine
coolant could require changing sooner, at
30,000 miles (50 000 km) or 24 months,
whichever occurs rst. Any repairs would not
be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your
vehicle.
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How to Add Coolant to the Coolant
Recovery Tank
If you have not found a problem yet, but the
coolant level is not 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. SeeEngine Coolant on page 375
for more information.
{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
CAUTION: (Continued)
CAUTION: (Continued)
could catch re and you or others could
be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.
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.
{CAUTION:
You can be burned if you spill coolant
on hot engine parts. Coolant contains
ethylene glycol and it will burn if the engine
parts are hot enough. Do not spill coolant
on a hot engine.
When the coolant in the coolant recovery tank is
at or above the full cold mark, start your vehicle.
383

If the overheat warning continues, there is one
more thing you can try. You can add the proper
coolant mixture directly to the radiator, but be sure
the cooling system is cool before you do it.
{CAUTION:
Steam and scalding liquids from a hot
cooling system can blow out and burn
you badly. They are under pressure, and if
you turn the radiator pressure cap — even
a little — they can come out at high
speed. Never turn the cap when the
cooling system, including the radiator
pressure cap, is hot. Wait for the cooling
system and radiator pressure cap to cool
if you ever have to turn the pressure cap.
How to Add Coolant to the Radiator
Notice:Your engine has a specic radiator ll
procedure. Failure to follow this procedure
could cause your engine to overheat and be
severely damaged.
1. Remove the radiator pressure cap when the
cooling system, including the radiator pressure
cap and upper radiator hose, is no longer hot.
Turn the pressure cap slowly counterclockwise
until it rst stops. Do not press down while
turning the pressure cap.
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If you hear a hiss, wait for that to stop. A hiss
means there is still some pressure left.
2. Then keep turning the pressure cap, but
now push down as you turn it. Remove
the pressure cap.
{CAUTION:
You can be burned if you spill coolant
on hot engine parts. Coolant contains
ethylene glycol and it will burn if the engine
parts are hot enough. Do not spill coolant
on a hot engine.3. After the engine cools, open the coolant air
bleed valves.
There are two bleed valves. One is located on
the thermostat housing. The other is located
on the thermostat bypass tube.HousingBypass Tube
385

4. Fill the radiator with the proper DEX-COOL®
coolant mixture, up to the base of the ller
neck. SeeEngine Coolant on page 375
for more information about the proper coolant
mixture.
If you see a stream of coolant coming from an
air bleed valve, close the valve. Otherwise,
close the valves after the radiator is lled.
5. Rinse or wipe any spilled coolant from the
engine and the compartment.6. Start the engine and let it run until you can
feel the upper radiator hose getting hot.
Watch out for the engine cooling fans.
7. By this time, the coolant level inside the
radiator ller neck may be lower. If the level is
lower, add more of the proper DEX-COOL
®
coolant mixture through the ller neck until the
level reaches the base of the ller neck.
Filling in the Radiator Filler NeckUpper Radiator Hose
386