2007 GMC ACADIA engine

CAUTION: (Continued)
If you keep driving when the vehicles
engine is overheated, the liquids in it can
catch re. You or others could be badly
burned. Stop your engine if it overheats,
and get out of the vehicle until the engine
is cool.
SeeOverheated Engine Protection
Operating Mode on page 412for
information on driving to a safe place in
an emergency.
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. SeeOverheated
Engine Protection Operating Mode on page 412
for 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 your air conditioner is on, turn it off.
2. Turn on your 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) or LOW (L).
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If you no longer have 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.
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 you still
have 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 397.
412

Cooling System
When you decide it is safe to lift the hood, here is
what you will see:
A. Engine Coolant Reservoir
B. Radiator Pressure Cap (covered)
C. Engine Cooling Fans{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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When the engine is cold, the coolant level should
be at least up to 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.
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
Notice:This vehicle has a specic coolant ll
procedure. Failure to follow this procedure
could cause your engine to overheat and
be severely damaged.
If you have not found a problem yet, check to see
if coolant is visible in the coolant recovery tank.
If coolant is visible 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
®
coolant at the coolant recovery tank, but be sure
the cooling system, including the coolant recovery
tank pressure cap, is cool before you do it. See
Engine Coolant on page 406for more information.
{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.
415

{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 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 the FULL COLD mark, start your vehicle.
If the overheat warning continues, there is one
more thing you can try. You can add the proper
mixture directly to the radiator, but be sure
the cooling system is cool before you do it.
416

1. To remove the panel that covers the radiator
cap, detach fasteners and lift off panel.
2. Remove the radiator pressure cap when the
cooling system, including the upper radiator
hose, is no longer hot. Turn the pressure cap
slowly counterclockwise about one full turn.
If you hear a hiss, wait for that to stop. A hiss
means there is still some pressure left.3. Keep turning the
pressure cap slowly,
and remove it.
4. Fill the radiator with the proper DEX-COOL®
coolant mixture, up to the base of the ller
neck. SeeEngine Coolant on page 406
for more information about the proper coolant
mixture.
417

5. Fill the coolant recovery tank to the FULL
COLD mark.
6. Reinstall the cap on the coolant recovery tank,
but leave the radiator pressure cap off.7. Start the engine and let it run until you can
feel the upper radiator hose getting hot.
Watch out for the engine cooling fan.
8. 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.
Replace the pressure cap.
At any time during this procedure if coolant begins
to ow out of the ller neck, reinstall the pressure
cap. Be sure to secure it tightly.
418