Page 248 of 388
Checking Things Under the Hood
A CAUTION:
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.
A CAUTION:
Things that burn can get on hot engine parts
and start
a fire. These include liquids like
gasoline
or diesel 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.
To open the hood, first
pull this handle inside the
vehicle. It is
just in front of
the driver’s side door frame
near the floor.
I
6-8
ProCarManuals.com
Page 252 of 388
Fan and Drive:
Removal of fan clutch (if equipped) or rendering
Removal of the fan shroud (if equipped).
Air Intake:
clutch inoperative.
0 Removal of the air cleaner silencer.
Reversing the air cleaner cover.
Exhaust:
Removal of the muffler and/or resonator.
Removal of the exhaust pipes and exhaust
pipe clamps.
Engine Oil (Gasoline Engine)
If your vehicle has a diesel engine, see “Engine Oil
(Diesel Engine)” in the Diesel Engine Supplement.
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 has
a yellow handle and is
located near the center
of
the engine compartment.
Turn
off the engine and
give the oil
a few minutes
to drain back into
the oil
pan. If you don’t, the oil
dipstick might not show
the actual level.
6-12
ProCarManuals.com
Page 253 of 388
Checking Engine Oil
Pull out the dipstick and clean it with a paper towel or
cloth, then push
it back in all the way. Remove it again,
keeping the tip down, and check the level.
When to Add Engine Oil
If the oil is at or below the ADD mark, then you’ll need
to add at least one quart of oil. But you must use the
right kind. This part explains what kind of oil to use. For
crankcase capacity, see “Capacities and Specifications”
in the Index.
I NOTICE:
Don’t add too much oil. If your engine has so
much oil that the oil level gets above the upper
mark that shows the proper operating range, your engine could be damaged.
The engine oil filler cap is located between the coolant
recovery tank and the air cleaner.
6-13
ProCarManuals.com
Page 257 of 388

5. Install a new filter element with the folds in the
down position.
Reverse Steps
1 through 4 to replace the air cleaner.
See “Normal Replacement Parts” for the proper filter
to use.
Refer to the Maintenance Schedule
to determine when to
replace the air filter and crankcase ventilation filter.
See “Scheduled Maintenance Services” in the Index.
I
Operating the engine with the air cleaner off can
cause you or others to be burned. The air cleaner
not only cleans the air,
it stops flame if the engine
backfires.
If it isn’t there, and the engine
backfires, you could be burned. Don’t drive with
it
off, and be careful working on the engine with
the air cleaner
off.
NOTICE:
If the air cleaner is off, a backfire can cause a
damaging engine fire. And, dirt can easily get
into your engine, which will damage
it. Always
have the air cleaner in place when you’re driving.
Automatic Transmission Fluid
If your vehicle has a diesel engine, see “Automatic
Transmission Fluid” in the Diesel Supplement.
When to Check and Change
A good time to check your automatic transmission fluid
level
is when the engine oil is changed.
Change both the fluid and filter every
50,000 miles
(83 000 km) if the vehicle’s GVWR is over 8,600 or
if the vehicle is mainly driven under one or more of
these conditions:
0 In heavy city traffic where the outside temperature
regularly reaches
90°F (32°C) or higher.
0 In hilly or mountainous terrain.
0 When doing frequent trailer towing.
6-17
ProCarManuals.com
Page 261 of 388

Rear Axle What to Use
When to Check and Change Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant and when to change it. See
“Scheduled Maintenance Services” in the Index.
How to Check Lu’_ -~I
If the level is below the
bottom of the filler plug
hole, you’ll need
to add
some lubricant. Add enough
lubricant to raise the level
to the bottom of the filler
plug hole. Refer
to the Maintenance Schedule to determine what
kind of lubricant to use. See “Recommended Fluids and
Lubricants”
in the Index.
Engine Coolant
The cooling s stem in your vehicle is filled with
DEX-COOL engine coolant. This coolant is designea
to remain
in your vehicle for 5 years or 150,000 miles
(240 000 km) whichever occurs first, if you add only
DEX-COOL6 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 “Engine Overheating” in the
Index.
A 50/50 mixture of water and DEX-COOL@
coolant will:
2
0 Give freezing protection down to -34°F (-37°C).
Give boiling protection up to 265 “F (129” C).
0 Protect against rust and corrosion.
0 Help keep the proper engine temperature.
0 Let the warning lights and gages work as
they should.
6-21
ProCarManuals.com
Page 308 of 388
Cooling System Capacity (Approximate)
ENGINE VIN QTY Without Rear Heater
“VORTEC”4300 W 11 Quarts (10.4 L)
“VORTEC”5000 M 17 Quarts (16 L)
“VORTEC”5700 R 17 Quarts (16 L)
“VORTEC”7400 J 23 Quarts (21.8 L)
QTY With Rear Heater
14 Quarts (13.2 L)
20 Quarts (18.9 L)
20 Quarts (18.9 L)
26 Quarts (24.6 L)
After refill, the level MUST be checked as outlined under “Engine Cooling System” in Section 5.
Crankcase Capacity (Approximate)
ENGINE VIN Quantity With Filter
“VORTEC”4300 W 4.5 Quarts (4.3 L)
“VORTEC”5000 M 5 Quarts (4.8 L)
“VORTEC”5700 R 5 Quarts (4.8 L)
“VORTEC”7400 J 6.6 Quarts (6.24 L)
After refill, the level MUST be rechecked. Add enough engine oil so that the fluid is within the proper operating
range. See “Engine Oil” in the Index.
*Add one additional quart for
RPO 5Z1 and RPO KL5 Models.
ProCarManuals.com
Page 320 of 388

Short ”kip/City Maintenance Schedule -- Gasoline Engines
The services shown in this schedule up to 100,000 miles
(166
000 km) should be performed after 100,000 miles
(166
000 km) at the same intervals. The services shown
at
150,000 miles (240 000 km) should be performed at
the same interval after
150,000 miles (240 000 km).
See “Owner Checks and Services” and “Periodic
Maintenance Inspections” following.
Footnotes
The U.S. Environmental Protection Agency or the
California Air Resources Board has determined that the
failure to perform this maintenance item will not nullify
the emission warranty or limit recall liability prior to the
completion of the vehicle’s useful life. We, however,
urge that all recommended maintenance services be
performed at the indicated intervals and the maintenance
be recorded.
# Lubricate the front suspension, kingpin bushings,
steering linkage and rear driveline center splines.
+ A good time to check your brakes is during tire
rotation. See “Brake System Inspection” under “Periodic
Maintenance Inspections” in Part
C of this schedule.
** Drive axle service (see “Recommended Fluids and
Lubricants” in the Index for proper lubricant to use):
e
e
e
Locking Differential -- Drain fluid and refill at first
engine oil change. At subsequent oil changes, check
fluid level and add fluid as needed.
If driving in
dusty areas
or towing a trailer, drain fluid and refill
every 15,000 miles
(25 000 km).
Standard Differential -- Check fluid level and add
fluid as needed at every oil change.
If driving in
dusty areas or towing a trailer, drain fluid and refill
every
15,000 miles (25 000 km).
More frequent lubrication may be required for
heavy-duty use.
7-8
ProCarManuals.com
Page 321 of 388

1
I Short Trip/Cits Maintenance Schedule -- Gasoline Engines I
3,000 Miles (5 000 km)
0 Change engine oil and filter (or every 3 months, whichever occurs first).
0 Lubricate chassis components (or every 3 months, whichever occws first).
0 Check axle fluid level and add fluid as needed. (See footnote **.)
An Emission Control Service.
(See footnote #.)
6,000 Miles (10 000 km)
0 Change engine oil and filter (or every 3 months, whichever occurs fiist).
0 Lubricate chassis components (or every 3 months, whichever occurs first).
0 Check axle fluid level and add fluid as needed. (See footnote **.)
Cl Rotate tires. See “Tire Inspection and Rotation” in the Index for proper
rotation pattern and additional information. (See footnote
+.)
An Emission Control Service.
(See footnote #.)
9,000 Miles (15 000 km)
0 Change engine oil and filter (or every 3 months, whichever occurs first).
0 Lubricate chassis components (or every 3 months, whichever occurs fiist).
0 Check axle fluid level and add fluid as needed. (See footnote **.)
An Emission Control Service.
(See footnote #.)
DATE I
DATE I
DATE I
7-9
ProCarManuals.com