2006 GMC YUKON Engine

To help keep fuel injectors and intake valves clean,
or if your vehicle experiences problems due to
dirty injectors or valves, look for gasoline that is
advertised as TOP TIER Detergent Gasoline. Also,
your GM dealer has additives that will help correct
and prevent most deposit-related problems.
Gasolines containing oxygenates, such as ethers and
ethanol, and reformulated gasolines may be available in
your area. General Motors recommends that you use
these gasolines if they comply with the specications
described earlier. However, E85 (85% ethanol)
and other fuels containing more than 10% ethanol
must not be used in vehicles that were not designed
for those fuels.
Notice:Your vehicle was not designed for fuel
that contains methanol. Do not use fuel containing
methanol. It can corrode metal parts in your fuel
system and also damage the plastic and rubber
parts. That damage would not be covered under
your warranty.
Some gasolines that are not reformulated for low
emissions may contain an octane-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask the attendant where you buy gasoline
whether the fuel contains MMT. General Motors
recommends against the use of such gasolines.Fuels containing MMT can reduce the life of spark plugs
and the performance of the emission control system
may be affected. The malfunction indicator lamp
may turn on. If this occurs, return to your authorized
GM dealer for service.
Fuel E85 (85% Ethanol)
The 8th digit of your vehicle identication number (VIN)
shows the code letter or number that identies your
engine. You will nd the VIN at the top left of the
instrument panel. SeeVehicle Identication Number
(VIN) on page 5-105.
If your vehicle has the 5.3L V8 engine (VIN Code Z
only), you may use either regular unleaded gasoline
or ethanol fuel containing up to 85% ethanol (E85);
also seeFuel on page 5-4. In all other engines, including
the 5.3L V8 (VIN Code T), use only regular unleaded
gasoline.
Only vehicles that have the 5.3L V8 engine (VIN Code Z)
may use 85% ethanol fuel (E85). General Motors
encourages the use of E85 in vehicles that are designed
to use it. The ethanol in E85 is a “renewable” fuel,
meaning it is made from renewable sources such as
corn and other crops.
5-6

Filling the Tank
{CAUTION:
Fuel vapor burns violently and a fuel re
can cause bad injuries. To help avoid injuries
to you and others, read and follow all the
instructions on the pump island. Turn off your
engine when you are refueling. Do not smoke
if you are near fuel or refueling your vehicle.
Keep sparks, ames, and smoking materials
away from fuel. Do not leave the fuel pump
unattended when refueling your vehicle — this
is against the law in some places. Keep
children away from the fuel pump; never let
children pump fuel.The tethered fuel cap is located behind a hinged fuel
door on the driver’s side of the vehicle.
To remove the fuel cap, turn it slowly counterclockwise.
It will require more effort to turn the fuel cap on the
last turn as you loosen it.
{CAUTION:
If you spill fuel and then something ignites it,
you could be badly burned. Fuel can spray out
on you if you open the fuel cap too quickly.
This spray can happen if your tank is nearly
full, and is more likely in hot weather. Open
the fuel cap slowly and wait for any hiss noise
to stop. Then unscrew the cap all the way.
5-8

Filling a Portable Fuel Container
{CAUTION:
Never ll 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 ll 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 ll nozzle in contact with the
inside of the ll opening before operating
the nozzle. Contact should be maintained
until the lling is complete.
Do not smoke while pumping gasoline.
Checking Things Under
the Hood
{CAUTION:
An electric 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.
{CAUTION:
Things that burn can get on hot engine parts
and start a re. These include liquids like fuel,
oil, coolant, brake uid, windshield washer
and other uids, 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.
5-10

Engine Compartment Overview
When you open the hood on the 5.3L V8 engine (4.8L and 6.0L V8 engines similar), here is what you will see:
5-12

A. Engine Air Cleaner/Filter. SeeEngine
Air Cleaner/Filter on page 5-20.
B. Coolant Surge Tank and Pressure Cap.
SeeCooling System on page 5-30andCoolant
Surge Tank Pressure Cap on page 5-27.
C. Air Filter Restriction Indicator (If Equipped).
SeeEngine Air Cleaner/Filter on page 5-20.
D. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil on page 5-15.
E. Automatic Transmission Dipstick. See “Checking
the Fluid Level” underAutomatic Transmission
Fluid on page 5-22.
F. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-15.
G. Engine Cooling Fan. SeeCooling System
on page 5-30.H. Remote Negative (−) Terminal (GND).
SeeJump Starting on page 5-42.
I. Power Steering Fluid Reservoir. SeePower
Steering Fluid on page 5-36.
J. Remote Positive (+) Terminal. SeeJump Starting
on page 5-42.
K. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-38.
L. Underhood Fuse Block. SeeUnderhood Fuse
Block on page 5-109.
M. Battery. SeeBattery on page 5-41.
N. Windshield Washer Fluid Reservoir. See
“Adding Washer Fluid” underWindshield Washer
Fluid on page 5-37.
5-13

When you open the hood on the 8.1L V8 engine, here is what you will see:
5-14

A. Engine Air Cleaner/Filter. SeeEngine
Air Cleaner/Filter on page 5-20.
B. Coolant Surge Tank and Pressure Cap.
SeeCooling System on page 5-30andCoolant
Surge Tank Pressure Cap on page 5-27.
C. Air Filter Restriction Indicator (If Equipped).
SeeEngine Air Cleaner/Filter on page 5-20.
D. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil on page 5-15.
E. Automatic Transmission Dipstick. See “Checking
the Fluid Level” underAutomatic Transmission
Fluid on page 5-22.
F. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-15.
G. Engine Cooling Fan. SeeCooling System
on page 5-30.
H. Remote Negative (−) Terminal (GND).
SeeJump Starting on page 5-42.
I. Remote Positive (+) Terminal. SeeJump Starting
on page 5-42.
J. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-36.
K. Brake Master Fluid Reservoir. See “Brake Fluid”
underBrakes on page 5-38.
L. Underhood Fuse Block. SeeUnderhood Fuse
Block on page 5-109.M. Battery. SeeBattery on page 5-41.
N. Windshield Washer Fluid Reservoir. See
“Adding Washer Fluid” underWindshield Washer
Fluid on page 5-37.
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 CHECK OIL LEVEL under
DIC Warnings and Messages on page 3-56.
You should check your engine oil level regularly; this is
an added reminder.
Checking Engine Oil
It is 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 loop.
SeeEngine Compartment Overview on page 5-12
for the location of the engine oil dipstick.
1. Turn off the engine and give the oil several minutes
to drain back into the oil pan. If you do not do this,
the oil dipstick might not show the actual level.
2. 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.
5-15

When to Add Engine Oil
If the oil is below the cross-hatched area at the tip of the
dipstick, you will need to add at least one quart/liter of oil.
But you must use the right kind. This section explains
what kind of oil to use. For engine oil crankcase capacity,
seeCapacities and Specications on page 5-114.Notice:Do not add too much oil. If the engine
has so much oil that the oil level gets above the
cross-hatched area that shows the proper operating
range, the engine could be damaged.
SeeEngine Compartment
Overview on page 5-12
for the location of the
engine oil ll cap.
Be sure to add enough oil to put the level somewhere
in the proper operating range. Push the dipstick all
the way back in when you are through. 8.1L Engine
All Except 8.1L Engine
5-16