2010 GMC YUKON engine coolant

Checking Coolant
The vehicle must be on a level surface when checking
the coolant level.
Check to see if coolant is visible in the coolant surge
tank. If the coolant inside the coolant surge tank is
boiling, do not do anything else until it cools down.
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 surge tank, but be sure the cooling system is
cool before this is done.
The coolant surge tank is located in the engine
compartment on the passenger side of the vehicle.
See Engine Compartment Overview
on page 6‑16for more information on location.
The coolant level should be at or above the
FULL COLD mark. If it is not, you may have a
leak in the cooling system.
6-33

How to Add Coolant to the Surge Tank
{WARNING:
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.
Notice: This vehicle has a specific coolant fill
procedure. Failure to follow this procedure could
cause the engine to overheat and be severely
damaged.
{WARNING:
An electric engine cooling fan under the hood can
start up even when the engine is not running and
can cause injury. Keep hands, clothing, and tools
away from any underhood electric fan.
{WARNING:
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 surge tank
pressure cap —even a little —they can come
out at high speed. Never turn the cap when the
cooling system, including the surge tank pressure
cap, is hot. Wait for the cooling system and surge
tank pressure cap to cool if you ever have to turn
the pressure cap.
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4. With the coolant surge tank pressure cap off,start the engine and let it run until you can feel the
upper radiator hose getting hot. Watch out for the
engine cooling fan.
By this time, the coolant level inside the coolant
surge tank may be lower. If the level is lower, add
more of the proper mixture to the coolant surge
tank until the level reaches the FULL COLD mark. 5. Replace the pressure cap. Be sure the pressure
cap is hand-tight and fully seated.
6. Verify coolant level after engine is shut off and the coolant is cold. If necessary, repeat coolant fill
procedure Steps 1 through 6.
Notice: If the pressure cap is not tightly installed,
coolant loss and possible engine damage may
occur. Be sure the cap is properly and tightly
secured.
Engine Overheating
The vehicle has several indicators to warn of engine
overheating.
There is a coolant temperature gauge on your vehicle's
instrument panel. See Engine Coolant Temperature
Gauge on page 4‑38.
In addition, ENGINE OVERHEATED STOP ENGINE,
ENGINE OVERHEATED IDLE ENGINE, and a ENGINE
POWER IS REDUCED message comes on in the Driver
Information Center (DIC) on the instrument panel.
See DIC Warnings and Messages on page 4‑61.
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You may decide not to lift the hood when this warning
appears, but instead get service help right away.
SeeRoadside Assistance Program on page 8‑7.
If you do decide to lift the hood, make sure the vehicle
is parked on a level surface.
Then check to see if the engine cooling fans are
running. If the engine is overheating, both fans should
be running. If they are not, do not continue to run the
engine and have the vehicle serviced.
Notice: Engine damage from running your engine
without coolant is not covered by the vehicle
warranty. See Overheated Engine Protection
Operating Mode for information on driving to
a safe place in an emergency.
Notice: If the engine catches fire while driving
with no coolant, the vehicle can be badly damaged.
The costly repairs would not be covered by the
vehicle warranty. See Overheated Engine Protection
Operating Mode
on page 6‑39for information on
driving to a safe place in an emergency.
If Steam Is Coming From The Engine
Compartment
{WARNING:
Steam from an overheated engine can burn you
badly, even if you just open the hood. Stay away
from the engine if you see or hear steam coming
from it. Turn it off and get everyone away from
the vehicle until it cools down. Wait until there
is no sign of steam or coolant before you open
the hood.
If you keep driving when the vehicles engine is
overheated, the liquids in it can catch fire. You or
others could be badly burned. Stop the engine if
it overheats, and get out of the vehicle until the
engine is cool.
See Overheated Engine Protection Operating
Mode
on page 6‑39for information on driving to
a safe place in an emergency.
6-37

If No Steam Is Coming From The
Engine Compartment
The ENGINE OVERHEATED STOP ENGINE or the
ENGINE OVERHEATED IDLE ENGINE message, along
with a low coolant condition, can indicate a serious
problem.
If an engine overheat warning is displayed but no steam
can be seen or heard, the problem may not be too
serious. Sometimes the engine can get a little too hot
when the vehicle:
.Climbs a long hill on a hot day.
.Stops after high-speed driving.
.Idles for long periods in traffic.
.Tows a trailer. SeeTowing a Trailer on page 5‑49.
If the overheat warning is displayed with no sign of
steam: 1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the highest fan speed. Open the windows as
necessary. 3. In heavy traffic, let the engine idle in N (Neutral)
while stopped. If it is safe to do so, pull off the
road, shift to P (Park) or N (Neutral) and let the
engine idle.
If the temperature overheat gauge is no longer in
the overheat zone or an overheat warning no longer
displays, the vehicle can be driven. Continue to drive
the vehicle slow for about 10 minutes. Keep a safe
vehicle distance from the car in front of you. If the
warning does not come back on, continue to drive
normally.
If the warning continues, pull over, stop, and park the
vehicle right away.
If there is no sign of steam, idle the engine for
three minutes while parked. If the warning is still
displayed, turn off the engine until it cools down.
Also, see “Overheated Engine Protection Operating
Mode” later in this section.
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Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
ENGINE POWER IS REDUCED message is displayed,
an overheat protection mode which alternates firing
groups of cylinders helps prevent engine damage.
In this mode, you will notice a loss in power and engine
performance. This operating mode allows the vehicle
to be driven to a safe place in an emergency. 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. See Engine Oil
on
page 6‑18.
Engine Fan Noise
If the vehicle has a clutched engine cooling fan, when
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most everyday driving
conditions, the fan is spinning slower and the clutch is
not fully engaged. This improves fuel economy and
reduces fan noise. Under heavy vehicle loading, trailer
towing, and/or high outside temperatures, the fan speed
increases as the clutch more fully engages, so you may
hear an increase in fan noise. This is normal and should
not be mistaken as the transmission slipping or making
extra shifts. It is merely the cooling system functioning
properly. The fan will slow down when additional cooling
is not required and the clutch disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch partially
disengages.
If the vehicle has electric cooling fans, you may hear
the fans spinning at low speed during most everyday
driving. The fans may turn off if no cooling is required.
Under heavy vehicle loading, trailer towing, and/or high
outside temperatures, or if you are operating the air
conditioning system, the fans may change to high
speed and you may hear an increase in fan noise.
This is normal and indicates that the cooling system is
functioning properly. The fans will change to low speed
when additional cooling is no longer required.
6-39

Windshield Washer Fluid
What to Use
When windshield washer fluid needs to be added, be
sure to read the manufacturer's instructions before use.
Use a fluid that has sufficient protection against freezing
in an area where the temperature may fall below
freezing.
Adding Washer Fluid
The vehicle has a low washer fluid message in
the DIC that comes on when the washer fluid is low.
The message is displayed for 15 seconds at the start of
each ignition cycle. When the WASHER FLUID LOW
ADD FLUID message displays, you will need to add
washer fluid to the windshield washer fluid reservoir.
Open the cap with the
washer symbol on it.
Add washer fluid until the
tank is full. SeeEngine
Compartment Overview
on page 6‑16for
reservoir location. Notice:
.When using concentrated washer fluid,
follow the manufacturer's instructions for
adding water.
.Do not mix water with ready-to-use washer
fluid. Water can cause the solution to freeze
and damage the washer fluid tank and other
parts of the washer system. Also, water does
not clean as well as washer fluid.
.Fill the washer fluid tank only three-quarters
full when it is very cold. This allows for fluid
expansion if freezing occurs, which could
damage the tank if it is completely full.
.Do not use engine coolant (antifreeze) in
the windshield washer. It can damage the
vehicle's windshield washer system and
paint.
6-41

When the Change Engine Oil Soon message displays,
certain services, checks, and inspections are required.
The services described for MaintenanceIshould be
performed at every engine oil change. The services
described for Maintenance IIshould be
performed when:
.Maintenance Iwas performed the last time the
engine oil was changed.
.It has been 10 months or more since the Change
Engine Oil Soon message has displayed or since
the last service.
Maintenance I
.Change engine oil and filter. See Engine Oilon
page 6‑18. An Emission Control Service.
.Engine coolant level check. See Engine Coolanton page 6‑32.
.Windshield washer fluid level check.
SeeWindshield Washer Fluid on page 6‑41.
.Tire inflation check. See Inflation - Tire Pressureon page 6‑72.
.Tire wear inspection. See Tire Inspection and
Rotation on page 6‑78.
.Rotate tires. See Tire Inspection and Rotationon
page 6‑78.
.Fluids visual leak check (or every 12 months,
whichever occurs first). A leak in any system must
be repaired and the fluid level checked.
.Engine air cleaner filter inspection (vehicles driven
in dusty conditions only). See Engine Air Cleaner/
Filter on page 6‑22.
.Brake system inspection (or every 12 months,
whichever occurs first).
Maintenance II
.Perform all services described in Maintenance I.
.Steering and suspension inspection. Visual
inspection for damaged, loose, or missing parts
or signs of wear.
.Lubricate the front suspension, steering linkage,
and parking brake cable guides. Control arm
ball joints on 2500 series vehicles require
lubrication but should not be lubricated unless
their temperature is−12°C (10°F) or higher, or
they could be damaged. Control arm ball joints
on 1500 series vehicles are maintenance‐free.
.Engine cooling system inspection. Visual
inspection of hoses, pipes, fittings, and clamps
and replacement, if needed.
7-4