2005 GMC YUKON tow

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.
When to Add Engine Oil
If the oil is at or below the cross-hatched area at the tip
of the dipstick, then you will need to add at least one
quart 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 5-12for
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 Other Engines
5-16

Then, without shutting off the engine, follow these steps:
The transmission dipstick
handle with this graphic is
located at the rear of
the engine compartment,
on the passenger’s
side of the vehicle.
SeeEngine Compartment Overview on page 5-12for
more information on location.
1. Flip the handle up and then pull out the dipstick
and wipe it with a clean rag or paper towel.
2. Push it back in all the way, wait three seconds and
then pull it back out again.3. Check both sides of the dipstick, and read the lower
level. The uid level must be in the COLD area,
below the cross-hatched area, for a cold check or in
the HOT or cross-hatched area for a hot check.
Be sure to keep the dipstick pointed down to get an
accurate reading.
4. If the uid level is in the acceptable range, push the
dipstick back in all the way; then ip the handle
down to lock the dipstick in place.
Consistency of Readings
Always check the uid level at least twice using the
procedure described previously. Consistency (repeatable
readings) is important to maintaining proper uid level.
If inconsistent readings persist, check the transmission
breather hose to be sure it is clean and unclogged.
If readings are still inconsistent, contact your dealer.
5-23

If No Steam Is Coming From Your
Engine
An overheat warning, along with a low coolant condition,
can indicate a serious problem.
If you get an engine overheat warning, but see or hear
no steam, the problem may not be too serious.
Sometimes the engine can get a little too hot when you:
Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.
Tow a trailer. SeeTowing a Trailer on page 4-67.
If you get the overheat warning with no sign of steam, try
this for a minute or so:
1. If you have an air conditioner and it is on, turn it off.
2. Turn on your heater to full hot at the highest fan
speed and open the windows as necessary.
3. In heavy traffic, let the engine idle in NEUTRAL (N)
while stopped. If it is safe to do so, pull off the road,
shift to PARK (P) or NEUTRAL (N) and let the
engine idle.If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning does not come back on, you can drive
normally.
If the warning continues, pull over, stop, and park your
vehicle right away.
If there is still no sign of steam and your vehicle is
equipped with an engine-driven cooling fan, push down
the accelerator until the engine speed is about twice
as fast as normal idle speed for at least three minutes
while you are parked.
If there is still no sign of steam and your vehicle is
equipped with an electric cooling fan, idle the engine for
three minutes while you are parked.
If you still have the warning,turn off the engine and get
everyone out of the vehicleuntil it cools down. Also,
see “Overheated Engine Protection Operating Mode”
later in this section.
You may decide not to lift the hood but to get service
help right away.
5-28

Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
REDUCED ENGINE POWER message is displayed, an
overheat protection mode which alternates ring
groups of cylinders helps prevent engine damage. In
this mode, you will notice a loss in power and engine
performance. This operating mode allows your vehicle to
be driven to a safe place in an emergency. Driving
extended miles (km) and/or towing a trailer in the
overheat protection mode should be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any
repair. The engine oil will be severely degraded.
Repair the cause of coolant loss, change the oil and
reset the oil life system. SeeEngine Oil on
page 5-15.
Cooling System
When you decide it is safe to lift the hood, here is what
you will see:
A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Cooling Fan8100 V8 Engines
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4. With the coolant surge tank pressure cap off, start
the engine and let it run until you can feel the upper
radiator hose getting hot. Watch out for the
engine cooling fan.
By this time, the coolant level inside the coolant
surge tank may be lower. If the level is lower, add
more of the proper mixture to the coolant surge tank
until the level reaches the FULL COLD mark.
5. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
Engine Fan Noise
If your vehicle is equipped with a clutched engine cooling
fan, when the clutch is engaged, the fan spins faster to
provide more air to cool the engine. In most everyday
driving conditions, the fan is spinning slower and the
clutch is not fully engaged. This improves fuel economy
and reduces fan noise. Under heavy vehicle loading,
trailer towing, and/or 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 slow down when
additional cooling is not required and the clutch
disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch partially
disengages.
If your vehicle is equipped with electric cooling fans, you
may hear the fans spinning at low speed during most
everyday driving. The fans may turn off if no cooling is
required. Under heavy vehicle loading, trailer towing,
and/or high outside temperatures, or if you are operating
your air conditioning system, the fans change to high
speed and you may hear an increase in fan noise. This
is normal and indicates that the cooling system is
functioning properly. The fans will change to low speed
when additional cooling is no longer required.
5-34

Front Turn Signal, Sidemarker and
Daytime Running Lamps
A. Sidemarker Lamp
B. Retainer ClipC. Front Turn Signal Lamp
D. Daytime Running
Lamp (DRL)
To replace a front turn signal, sidemarker or DRL bulb,
do the following:
1. Open the hood. SeeHood Release on page 5-11
for more information.
2. Remove the headlamp assembly as described
previously. SeeHeadlamps on page 5-50for
more information.3. Press the retainer clip (B), located behind the turn
signal assembly, towards the outside of the vehicle.
4. Pull the turn signal assembly out of the vehicle.
5. Press the locking release lever, turn the bulb socket
counterclockwise and remove it from the turn signal
assembly.
6. Remove the old bulb from the bulb socket.
7. Install a new bulb into the bulb socket.
8. Insert the bulb socket into the turn signal assembly
and turn it clockwise until it locks.
5-51

Replacement Bulbs
Exterior Lamp Bulb Number
Back-up Lamp 3157
Daytime Running Lamps (DRL) 4114K
Front Roof Marker Lamp 194
Front Parking and Turn Lamp 3457A
Headlamps
High-Beam 9005
Low-Beam 9006
Rear Marker Lamp, Taillamp and
Stoplamp3157
Rear Turn Signal Lamp 3157
For replacement bulbs not listed here, contact your
dealer.
Windshield Wiper Blade
Replacement
Windshield wiper blades should be inspected at least
twice a year for wear and cracking. SeeScheduled
Maintenance on page 6-4for more information.
Replacement blades come in different types and are
removed in different ways. For proper type and length,
seeNormal Maintenance Replacement Parts on
page 6-15.To replace the windshield wiper blade assembly do the
following:
1. Lift the wiper arm and turn the blade until it is
facing away from the windshield.
2. Push the release lever and slide the wiper assembly
toward the driver’s side of the vehicle.
3. Install a new blade by reversing Steps 1 and 2.
5-56

When rotating your tires, always use the correct rotation
pattern shown here.
Do not include the spare tire in your tire rotation.
After the tires have been rotated, adjust the front and
rear ination pressures as shown on the tire and loading
information label. SeeLoading Your Vehicle on
page 4-51andInation - Tire Pressure on page 5-64,
for more information. Make certain that all wheel
nuts are properly tightened. See “Wheel Nut Torque”
underCapacities and Specications on page 5-114.
{CAUTION:
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after a time. The wheel could
come off and cause an accident. When you
change a wheel, remove any rust or dirt from
places where the wheel attaches to the vehicle.
In an emergency, you can use a cloth or a
paper towel to do this; but be sure to use a
scraper or wire brush later, if needed, to get all
the rust or dirt off. SeeChanging a Flat Tire on
page 5-76.
5-69