Page 201 of 372

A CAUTIO1 . .
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.
I NOTICE:
Engine damage from running your engine
without coolant isn’t covered by your warranty.
~~ ~ ~
If there seems to be no leak, start the engine again. See
if the 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.
How to Add Coolant to the Coolant
Recovery Tank
If you haven’t found a problem yet, but the coolant level
isn’t at the
FULL COLD mark, add a 50150 mixture of
clean water (preferably distilled) and DEX-COOL
(orange-colored, silicate-free) antifreeze at the coolant
recovery tank. (See “Engine Coolant”
in the Index for
more information.)
Adding only plain water
to your cooling system
can be dangerous. Plain water, or some other
liquid like alcohol, can boil before the proper
coolant mix will. Your vehicle’s coolant warning
system is set for the proper coolant mix. With
plain water or the wrong mix, 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 mix of clean
water and DEX-COOL
TM antifreeze.
5-13
ProCarManuals.com
Page 202 of 372
I 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 mix.
I A 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 mix
directly to the radiator, but be sure the cooling system
is
cool before you do it.
5-14
ProCarManuals.com
Page 206 of 372
5. Put the cap back on the coolant recovery tank, but
leave the radiator pressure cap
off.
I ., . k.
6. Start the engine and let it run until you can feel the
upper radiator hose getting hot. Watch out for the
engine fan.
filler neck may be lower.
If the level is lower, add
more of the proper
mix through the filler neck until
the level reaches the base of the filler neck.
7. By this time the coolant level inside the radiator
5-18
i
ProCarManuals.com
Page 207 of 372
Under heavy vehicle loading, trailer towing andor 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
the clutch partially disengages.
- slow down when additional cooling is not required and
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
arrows on
the pressure cap line up like this.
You may also hear this fan noise when you start
the engine.
It will go away as the fan clutch
partially disengages.
5-19
ProCarManuals.com
Page 232 of 372
When you lift the hood, ~011’11 see these items:
A. Battery
B. Coolant Recovery Tank
C. Engine Oil Dipstick
D. Engine Oil Fill
E. Transmission Dipstick
F. Air Cleaner
G. Power Steering Reservoir
H. Brake Master Cylinder
I. Windshield Washer Fluid
ProCarManuals.com
Page 233 of 372

If your vehicle has a 7.4L engine and air conditioning,
your vehicle will have a auxiliary engine fan
in addition
to the belt driven
fdn.
If your vehicle has air conditioning, the auxiliary
engine fan under the hood can start up and
injure you even when the engine is not running.
Keep hands, clothing and tools away from any
underhood electric fan.
~ Things that burn can get on hot engine parts and
start a
fire. These include liquids like gasoline,
~ 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. Before closing
the hood, be sure
all the filler caps are
on properly.
Then
lift the hood to relieve pressure on the hood prop.
Remove the hood prop from the slot
in the hood and
return the prop to
its retainer. Then just let the hood
down and close
it firmly.
Noise Control System
The following information relates to compliance with
Federal noise emission standards for vehicles with a
Gross Vehicle Weight Rating (GVWR) of more than
10,000 lbs. (4 536 kg). The Maintenance Schedule
booklet provides information on maintaining the noise
control system to minimize degradation of the noise
emission control system during the life of your vehicle.
The noise control system warranty is given
in your
Warranty booklet.
These standards apply only
to vehicles sold in the
United States.
6-9
ProCarManuals.com
Page 244 of 372

Engine Coolant
The cooling system in your vehicle is filled with new
DEX-COOL TM (orange-colored, silicate-free) engine
coolant. This coolant is designed to remain
in your
vehicle for
5 years or 100,000 miles (166 000 km),
whichever occurs first.
The following explains your cooling system and how
to
add coolant when it is low. If you have a problem with
engine overheating, see “Engine Overheating” in
the Index.
A 50/50 mixture of water and the proper coolant for
your vehicle will:
Give freezing protection down to -34°F (-37°C).
Give boiling protection up to 265 “F ( 129 O C).
0 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
DEX-COOL TM (orange-colored, silicate-free)
coolant meeting GM Specification 6277M.
If
silicated coolant 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.
6-20
ProCarManuals.com
Page 245 of 372
What to Use
Use a mixture of one-half clean water (preferably
distilled) and one-half
DEX-COOL TM (orange-colored,
silicate-free) antifreeze that meets
GM Specification
6277M, which won’t damage aluminum parts. Use
GM Engine Coolant Supplement (sealer) (GM Part
No. 3634621) with any complete coolant change. If you
use this mixture, you don’t need to add anything else. Adding
only plain water to your cooling system
can be dangerous. Plain water,
or some other
liquid like alcohol, can boil before the proper
coolant mix will. Your vehicle’s coolant warning
system is set for the proper coolant mix. With
plain water or the wrong mix, 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 mix of clean
water and
DEX-COOL TM (orange-colored,
silicate-free) antifreeze.
6-21
ProCarManuals.com