fuel GMC ENVOY DENALI 2008 Service Manual

Tires
To clean the tires, use a stiff brush with tire cleaner.
Notice:Using petroleum-based tire dressing
products on your vehicle may damage the paint
nish and/or tires. When applying a tire dressing,
always wipe off any overspray from all painted
surfaces on your vehicle.
Sheet Metal Damage
If the vehicle is damaged and requires sheet metal
repair or replacement, make sure the body repair shop
applies anti-corrosion material to parts repaired or
replaced to restore corrosion protection.
Original manufacturer replacement parts will provide the
corrosion protection while maintaining the warranty.
Finish Damage
Any stone chips, fractures or deep scratches in the
nish should be repaired right away. Bare metal
will corrode quickly and may develop into major repair
expense.
Minor chips and scratches can be repaired with touch-up
materials available from your dealer/retailer. Larger
areas of nish damage can be corrected in your
dealer’s/retailer’s body and paint shop.
Underbody Maintenance
Chemicals used for ice and snow removal and dust
control can collect on the underbody. If these are not
removed, corrosion and rust can develop on the
underbody parts such as fuel lines, frame, oor pan,
and exhaust system even though they have corrosion
protection.
At least every spring, ush these materials from the
underbody with plain water. Clean any areas where mud
and debris can collect. Dirt packed in close areas of the
frame should be loosened before being ushed. Your
dealer/retailer or an underbody car washing system can
do this for you.
Chemical Paint Spotting
Some weather and atmospheric conditions can create a
chemical fallout. Airborne pollutants can fall upon and
attack painted surfaces on the vehicle. This damage can
take two forms: blotchy, ring-shaped discolorations, and
small, irregular dark spots etched into the paint surface.
Although no defect in the paint job causes this, we will
repair, at no charge to the owner, the surfaces of
new vehicles damaged by this fallout condition within
12 months or 12,000 miles (20 000 km) of purchase,
whichever occurs rst.
5-106

Fuses Usage
51 Driver Side Trailer Turn
52 Hazard Flashers
53 Headlamp Driver Module
54Air Injection Reactor (AIR)
Solenoid
56 Air Injection Reactor (AIR) Pump
58Vehicle Stability Enhancement
System (StabiliTrak
®)
59 Regulated Voltage Control
Relays Usage
37 Headlamp Wiper
38 Rear Window Wiper/Washer
39 Fog Lamps
40 Horn
Relays Usage
41 Fuel Pump
42 Windshield Washer
43 High-Beam Headlamp
44 Air Conditioning
45 Cooling Fan
46 Headlamp Driver Module
47 Starter
49 Electric Adjustable Pedal
55 Air Injection Reactor (AIR) Solenoid
57 Powertrain
Miscellaneous Usage
48 Instrument Panel Battery
5-113

Fuses Usage
56 Injector Bank B
57 Headlamp Driver Module
58 Truck Body Controller 1
59 Electric Adjustable Pedal
61Vehicle Stability Enhancement
System (StabiliTrak
®)
62 Regulated Voltage Control
Relays Usage
37 Headlamp Wiper
38 Rear Window Wiper/Washer
39 Fog Lamps
40 Horn
41 Fuel Pump
42 Windshield Washer
43 High-Beam Headlamp
44 Air Conditioning
45 Cooling Fan
46 Headlamp Driver Module
Relays Usage
47 Starter
49 Electric Adjustable Pedal
60 Powertrain
Miscellaneous Usage
48 Instrument Panel Battery
Rear Underseat Fuse Block
5-116

ApplicationCapacities
English Metric
Fuel Tank 22.0 gal 83.3 L
Transfer Case Lubricant 2.0 qt 1.8 L
Transmission (Drain and Rell) 5.0 qt 4.7 L
Wheel Nut Torque 100 lb ft 140Y
All capacities are approximate. When adding, be sure to ll to the appropriate level, as recommended in this
manual. Recheck the uid level after lling.
Engine Specications
Engine VIN Code Transmission Spark Plug Gap
4.2L L6 S Automatic 0.040 inches (1.01 mm)
5.3L V8 M Automatic 0.040 inches (1.01 mm)
5-121

Maintenance Schedule......................................6-2
Introduction...................................................6-2
Maintenance Requirements..............................6-2
Your Vehicle and the Environment....................6-2
Using the Maintenance Schedule......................6-3
Scheduled Maintenance...................................6-4
Additional Required Services............................6-6
Maintenance Footnotes...................................6-7Owner Checks and Services............................6-9
At Each Fuel Fill............................................6-9
At Least Once a Month...................................6-9
At Least Once a Year...................................6-10
Recommended Fluids and Lubricants...............6-12
Maintenance Replacement Parts.....................6-14
Engine Drive Belt Routing..............................6-15
Maintenance Record.....................................6-16
Section 6 Maintenance Schedule
6-1

Using the Maintenance Schedule
We want to help you keep your vehicle in good working
condition. But we do not know exactly how you will
drive it. You might drive very short distances only a few
times a week. Or you might drive long distances all
the time in very hot, dusty weather. You might use your
vehicle in making deliveries. Or you might drive it to
work, to do errands, or in many other ways.
Because of all the different ways people use their
vehicles, maintenance needs vary. You might need more
frequent checks and replacements. So please read
the following and note how you drive. If you have any
questions on how to keep your vehicle in good condition,
see your dealer/retailer.
This schedule is for vehicles that:
carry passengers and cargo within recommended
limits. You will nd these limits on the Tire and
Loading Information label. SeeLoading Your
Vehicle on page 4-34.
are driven on reasonable road surfaces within legal
driving limits.
are driven off-road in the recommended manner.
SeeOff-Road Driving on page 4-13.
use the recommended fuel. SeeGasoline Octane
on page 5-6.The services inScheduled Maintenance on page 6-4
should be performed when indicated. SeeAdditional
Required Services on page 6-6andMaintenance
Footnotes on page 6-7for further information.
{CAUTION:
Performing maintenance work on a vehicle can
be dangerous. In trying to do some jobs, you
can be seriously injured. Do your own
maintenance work only if you have the
required know-how and the proper tools and
equipment for the job. If you have any doubt,
see your dealer/retailer to have a qualied
technician do the work. SeeDoing Your Own
Service Work on page 5-4.
Some maintenance services can be complex. So,
unless you are technically qualied and have the
necessary equipment, you should have your
dealer/retailer do these jobs.
6-3

Additional Required Services
The following services should be performed at the rst maintenance service (IorII) after the indicated miles (kilometers)
shown for each item.
Additional Required Services
Service and Miles (Kilometers)25,000
(40 000)50,000
(80 000)75,000
(120 000)100,000
(160 000)125,000
(200 000)150,000
(240 000)
Inspect fuel system for damage
or leaks.• •••••
Inspect exhaust system for loose or
damaged components.• •••••
Replace engine air cleaner lter. See
Engine Air Cleaner/Filter on page 5-21.•••
Change automatic transmission uid
and lter (severe service).
See footnotes (g) and (h).•••
Change automatic transmission
uid and lter (normal service).
See footnote (g).•
Automatic transfer case only: Change
transfer case uid.See footnote (g).•••
Replace spark plugs.An Emission
Control Service.•
V8 engine only: Inspect spark plug
wires.An Emission Control Service.•
6-6

(e)Make sure the safety belt reminder light and safety
belt assemblies are working properly. Look for any
other loose or damaged safety belt system parts. If you
see anything that might keep a safety belt system
from doing its job, have it repaired. Have any torn or
frayed safety belts replaced. Also see Checking
the Restraint Systems on page 1-68.
(f)Lubricate all key lock cylinders, hood latch assembly,
secondary latch, pivots, spring anchor, release pawl,
rear compartment hinges, outer liftgate handle pivot
points, rear door detent link, roller mechanism, liftgate
handle pivot points, latch bolt, fuel door hinge, cargo
door hinge, locks, and folding seat hardware. More
frequent lubrication may be required when exposed to a
corrosive environment. Applying silicone grease on
weatherstrips with a clean cloth will make them
last longer, seal better, and not stick or squeak.
(g)Inspect hoses for cracks, chafing, leaks, kinks, and
proper installation.(h)Change automatic transmission fluid and filter if the
vehicle is mainly driven under one or more of these
conditions:
In heavy city traffic where the outside temperature
regularly reaches 90°F (32°C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police, or delivery
service.
(i)Drain, flush, and refill cooling system. This service
can be complex; you should have your dealer/retailer
perform this service. See Engine Coolant on page 5-26
for what to use. Inspect hoses. Clean radiator,
condenser, pressure cap, and filler neck. Pressure test
the cooling system and pressure cap.
(j)A fluid loss in any vehicle system could indicate a
problem. Have the system inspected and repaired and
the fluid level checked. Add fluid if needed.
(k)If you drive regularly under dusty conditions, inspect
the filter at each engine oil change.
(l)Visually inspect belt for fraying, excessive cracks, or
obvious damage. Replace belt if necessary.
6-8

Owner Checks and Services
These owner checks and services should be performed
at the intervals specied to help ensure the safety,
dependability, and emission control performance of your
vehicle. Your dealer/retailer can assist you with these
checks and services.
Be sure any necessary repairs are completed at once.
Whenever any uids or lubricants are added to your
vehicle, make sure they are the proper ones, as shown
inRecommended Fluids and Lubricants on page 6-12.
At Each Fuel Fill
It is important to perform these underhood checks at
each fuel fill.
Engine Oil Level Check
Notice:It is important to check the engine oil
regularly and keep it at the proper level. Failure to
keep the engine oil at the proper level can cause
damage to the engine not covered by your warranty.
Check the engine oil level and add the proper oil if
necessary. SeeEngine Oil on page 5-16.
Engine Coolant Level Check
Check the engine coolant level and add DEX-COOL®
coolant mixture if necessary. SeeEngine Coolant
on page 5-26.
Windshield Washer Fluid Level Check
Check the windshield washer uid level in the windshield
washer uid reservoir and add the proper uid if
necessary.
At Least Once a Month
Tire Ination Check
Inspect your vehicle’s tires and make sure they are
inated to the correct pressures. Do not forget to
check the spare tire. SeeInflation - Tire Pressure on
page 5-64. Check to make sure the spare tire is stored
securely. SeeChanging a Flat Tire on page 5-82.
Tire Wear Inspection
Tire rotation may be required for high mileage highway
drivers prior to the Engine Oil Life System service
notication. Check the tires for wear and, if necessary,
rotate the tires. SeeTire Inspection and Rotation on
page 5-72.
6-9

Usage Fluid/Lubricant
Transfer CaseAUTO-TRAK II Fluid
(GM Part No. U.S. 12378508, in
Canada 10953626).
Rear Driveline
Center Spline
and Universal
JointsChassis Lubricant
(GM Part No. U.S. 12377985, in
Canada 88901242) or lubricant
meeting requirements of NLGI #2,
Category LB or GC-LB.
Constant
Velocity
Universal JointChassis Lubricant
(GM Part No. U.S. 12377985, in
Canada 88901242) or lubricant
meeting requirements of NLGI #2,
Category LB or GC-LB.
Hood Latch
Assembly,
Secondary
Latch, Pivots,
Spring
Anchor, and
Release PawlLubriplate Lubricant Aerosol
(GM Part No. U.S. 12346293, in
Canada 992723) or lubricant
meeting requirements of NLGI #2,
Category LB or GC-LB.Usage Fluid/Lubricant
Hood and Door
Hinges, Body
Door Hinge
Pins, Liftgate
Hinge and
Linkage,
Folding Seats,
and Fuel
Door HingeMulti-Purpose Lubricant, Superlube
(GM Part No. U.S. 12346241, in
Canada 10953474).
Outer Tailgate
Handle Pivot
Points and
HingesMulti-Purpose Lubricant, Superlube
(GM Part No. U.S. 12346241, in
Canada 10953474).
Weatherstrip
ConditioningWeatherstrip Lubricant
(GM Part No. U.S. 3634770,
in Canada 10953518) or
Dielectric Silicone Grease
(GM Part No. U.S. 12345579, in
Canada 992887).
Weatherstrip
SqueaksSynthetic Grease with
Teon, Superlube
(GM Part No. U.S. 12371287, in
Canada 10953437).
6-13