2002 GMC ENVOY radiator cap

5-10
If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning doesn't come back on, you can
drive normally.
If the warning continues, pull over, stop, and park your
vehicle right away.
If there's still no sign of steam, push down the
accelerator until the engine speed is about twice as fast
as normal idle speed for at least three minutes while
you're parked. If you still have the warning, turn off
the engine and get everyone out of the vehicle until it
cools down.
You may decide not to lift the hood but to get service
help right away.Cooling System
When you decide it's safe to lift the hood, here's what
you'll see:
A. Coolant Recovery Tank
B. Radiator Pressure Cap
C. Engine Fan
If the coolant inside the coolant recovery tank is boiling,
don't do anything else until it cools down.

5-11
When the engine is
cold, the coolant
level should be at
least up to the FULL
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.
If there seems to be no leak, start the engine again. See if
the engine cooling fan speed increases 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.
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.

5-13
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.
When the coolant in the coolant recovery tank is at the
FULL COLD mark, start your vehicle.
If the overheat warning continues, there's 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
CAUTION: (Continued)
CAUTION: (Continued)
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.

5-14 How to Add Coolant to the Radiator
1. You can 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 about
one full turn.
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. Remove the
pressure cap.

5-15
3. Fill the radiator with the proper DEX-COOL

coolant mixture, up to the base of the filler neck. See
ªEngine Coolantº in the Index for more information
about the proper coolant mixture.
4. Then fill the coolant recovery tank to the FULL
COLD mark.
5. Put the cap back on the coolant recovery tank, but
leave the radiator pressure cap off.

5-16
6. Start the engine and let it run until you can feel the
upper radiator hose getting hot. Watch out for the
engine cooling fan.
7. By this time, the coolant level inside the radiator
filler neck may be lower. If the level is lower, add
more of the proper DEX
-COOL
coolant mixture
through the filler neck until the level reaches the
base of the filler neck.
8. Then replace the pressure cap. At any time during
this procedure if coolant begins to flow out of the
filler neck, reinstall the pressure cap. Be sure the
pressure cap is hand
-tight.

6-
6-1
Section 6 Service and Appearance Care
Here 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
-15 Engine Air Cleaner/Filter
6
-17 Automatic Transmission Fluid
6
-20 Rear Axle
6
-21 Four-Wheel Drive
6
-23 Engine Coolant
6
-26 Radiator Pressure Cap
6
-27 Power Steering Fluid
6
-28 Windshield Washer Fluid
6
-29 Brakes6
-33 Battery
6
-33 Bulb Replacement
6
-36 Windshield Wiper Blade Replacement
6
-38 Tires
6
-46 Appearance Care
6
-47 Cleaning the Inside of Your Vehicle
6
-49 Care of Safety Belts
6
-50 Cleaning the Outside of Your Vehicle
6
-54 GM Vehicle Care/Appearance Materials
6
-55 Vehicle Identification Number (VIN)
6
-55 Service Parts Identification Label
6
-56 Electrical System
6
-63 Replacement Bulbs
6
-63 Capacities and Specifications
6
-64 Normal Maintenance Replacement Parts

6-11
A. Coolant Recovery Tank
B. Engine Air Cleaner/Filter
C. Windshield Washer
Fluid Reservoir
D. Engine Air Cleaner/Filter Indicator
E. Power Steering Fluid Reservoir
F. Automatic Transmission Dipstick
G. Engine Oil Dipstick
H. Radiator Pressure Cap
I. Engine Oil Fill Cap
J. Front Engine Lift Bracket Marked ªGNDº
K. Brake Master Cylinder
L. Battery
M. Engine Compartment Fuse Block
Before closing the hood, be sure all filler caps are on
properly. Then lift the hood to relieve pressure on the
hood prop. Remove the hood prop from its slot in the
hood and return the prop to its retainer. Then pull the
hood down firmly to close. It will latch when dropped
from 6 to 8 inches (15 to 20 cm) without pressing on
the hood.Engine Oil
If the CHECK 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 Oil Level Messageº in the Index.
You should check your engine oil level regularly; this is
an added reminder.
Checking Engine Oil
It's a good idea to check your engine oil every time you
get fuel. In order to get an accurate reading, the oil must
be warm and the vehicle must be on level ground.
The engine oil dipstick
handle is a yellow ring
located in the engine
compartment toward the
passenger's side of the
vehicle. See ªEngine
Compartment Overviewº
in the Index for more
information on location.