engine coolant GMC YUKON XL 2002 User Guide

5-12Cooling System When you decide it's safe to lift the hood, here's what
you'll see:
A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Fan
If the coolant inside the coolant surge tank is boiling,
don't do anything else until it cools down. The vehicle
should be parked on a level surface. The coolant level should
be at or above the FILL
COLD mark. If it isn't,
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. Don't touch them. If you
do, you can be burned.
Don't run the engine if there is a leak. If you run
the engine, it could lose all coolant. That could
cause an engine fire, and you could be burned.
Get any leak fixed before you drive the vehicle.

5-13If there seems to be no leak, start the engine again.
The engine cooling fan speed should increase when idle
speed is doubled by pushing the accelerator pedal down.
If it doesn't, your vehicle needs service. Turn off
the engine.
NOTICE: Engine damage from running your engine
without coolant isn't covered by your warranty.
See ªOverheated Engine Protection Operating
Modeº in the Index. NOTICE: When adding coolant, it is important that you
use only DEX
- COOL

(silicate
- free) coolant.
If coolant other than DEX
- COOL is added to
the system, premature engine, heater core or
radiator corrosion may result. In addition, the
engine coolant will require change sooner
-- at
30,000 miles (50 000 km) or 24 months,
whichever occurs first. Damage caused by the
use of coolant other than DEX
- COOL

is not
covered by your new vehicle warranty.

5-14How to Add Coolant to the Coolant
Surge Tank If you haven't found a problem yet, check to see if
coolant is visible in the surge tank. If coolant is visible
but the coolant level isn't at or above the FILL 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, including the coolant surge tank
pressure cap, is cool before you do it. See ªEngine
Coolantº in the Index for more information.
If no coolant is visible in the surge tank, add coolant
as follows: 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 coolant surge
tank pressure cap
-- even a little
-- they can come
out at high speed. Never turn the cap when the
cooling system, including the coolant surge tank
pressure cap, is hot. Wait for the cooling system
and coolant surge tank pressure cap to cool if you
ever have to turn the pressure cap.

5-15CAUTION: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. NOTICE: In cold weather, water can freeze and crack the
engine, radiator, heater core and other parts.
So use the recommended coolant.
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. Don't spill coolant on a hot engine.

5-18 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 FILL COLD mark. 5. Then replace the pressure cap. Be sure the pressure
cap is hand
- tight and fully seated.

6-
6-1Section 6 Service and Appearance CareHere you will find information about the care of your vehicle. This section begins with service and fuel information,
and then it shows how to check important fluid and lubricant levels. There is also technical information about your
vehicle, and a part devoted to its appearance care.
6
- 2 Service
6
- 3 Fuel
6
- 5 Fuels in Foreign Countries
6
- 6 Filling Your Tank
6
- 8 Filling a Portable Fuel Container
6
- 8 Checking Things Under the Hood
6
- 11 Engine Oil
6
- 17 Engine Air Cleaner/Filter
6
- 19 Passenger Compartment Air Filter
6
- 20 Automatic Transmission Fluid
6
- 23 Rear Axle
6
- 24 All
- Wheel Drive
6
- 26 Engine Coolant
6
- 29 Coolant Surge Tank Pressure Cap
6
- 30 Power Steering Fluid 6
- 31 Windshield Washer Fluid
6
- 32 Brakes
6
- 36 Battery
6
- 37 Bulb Replacement
6
- 41 Windshield Wiper Blade Replacement
6
- 42 Tires
6
- 51 Appearance Care
6
- 51 Cleaning the Inside of Your Vehicle
6
- 55 Cleaning the Outside of Your Vehicle
6
- 59 GM Vehicle Care/Appearance Materials
6
- 60 Vehicle Identification Number (VIN)
6
- 61 Electrical System
6
- 69 Replacement Bulbs
6
- 70 Capacities and Specifications
6
- 71 Normal Maintenance Replacement Parts

6-8Filling a Portable Fuel Container
CAUTION:Never fill a portable fuel container while it is in
your vehicle. Static electricity discharge from the
container can ignite the gasoline vapor. You can
be badly burned and your vehicle damaged if this
occurs. To help avoid injury to you and others:

Dispense gasoline only into
approved containers.

Do not fill a container while it is inside a
vehicle, in a vehicle's trunk, pickup bed or
on any surface other than the ground.

Bring the fill nozzle in contact with the
inside of the fill opening before operating
the nozzle. Contact should be maintained
until the filling is complete.

Don't smoke while pumping gasoline. Checking Things Under the Hood
CAUTION: Things that burn can get on hot engine parts and
start a fire. These include liquids like fuel, oil,
coolant, brake fluid, windshield washer and other
fluids, and plastic or rubber. You or others could
be burned. Be careful not to drop or spill things
that will burn onto a hot engine.

6-11A. Engine Air Cleaner/Filter
B. Coolant Surge Tank
C. Air Filter Restriction Indicator
D. Engine Oil Dipstick
E. Engine Oil Fill
F. Automatic Transmission Dipstick
G. Fan
H. Remote Negative (
- ) Terminal (GND)
I. Remote Positive (+) Terminal
J. Power Steering Fluid Reservoir (Out of View)
K. Brake Master Cylinder Reservoir
L. Underhood Fuse Block
M. Battery
N. Windshield Washer Fluid Reservoir
Before closing the hood, be sure all filler caps are on
properly. Pull down the hood and close it firmly. Engine Oil If the CHECK ENG OIL
LEVEL message appears
on the instrument cluster,
it means you need to check
your engine oil level
right away.
For more information, see ªCHECK ENG OIL LEVELº
in the Index.
You should check your engine oil level regularly; this is
an added reminder.

6-26 When the differential is cold, add enough lubricant
to raise the level to 1/2 inch (12 mm) below the filler
plug hole.
When the differential is at operating temperature
(warm), add enough lubricant to raise the level to
the bottom of the filler plug hole.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See ªRecommended Fluids
and Lubricantsº in the Index.
Engine Coolant The cooling system in your vehicle is filled with
DEX
- COOL 
engine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs first, if you add only
DEX
- COOL 
extended life coolant.
The following explains your cooling system and how
to add coolant when it is low. If you have a problem
with engine overheating, see ªEngine Overheatingº in
the Index. A 50/50 mixture of clean, drinkable water and
DEX
- COOL 
coolant will:

Give freezing protection down to
- 34  F (
- 37  C).

Give boiling protection up to 265  F (129  C).

Protect against rust and corrosion.

Help keep the proper engine temperature.

Let the warning lights and gages work as
they should.
NOTICE: When adding coolant, it is important that you
use only DEX
- COOL 
(silicate
- free) coolant.
If coolant other than DEX
- COOL is added to
the system, premature engine, heater core or
radiator corrosion may result. In addition, the
engine coolant will require change sooner
-- at
30,000 miles (50 000 km) or 24 months,
whichever occurs first. Damage caused by the
use of coolant other than DEX
- COOL 
is not
covered by your new vehicle warranty.

6-27What 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
don't need to add anything else.
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 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. 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.
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 to
add extra inhibitors or additives which claim to
improve the system. These can be harmful.