check engine GMC SIERRA CLASSIC 2007 Service Manual

A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Cooling Fan
{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.
If the coolant inside the coolant surge tank is
boiling, do not do anything else until it cools down.
The vehicle should be parked on a level surface.
Check the coolant level after the system cools
down. Some amount of coolant may be lost due to
overheating.
All Other Engines
509

The coolant level should
be at or above the FULL
COLD mark. If it is not,
you may have a leak at
the pressure cap or in
the radiator hoses,
heater hoses, radiator,
water pump, or
somewhere else in the
cooling system.
{CAUTION:
Heater and radiator hoses, and other
engine parts, can be very hot. Do not
touch them. If you do, you can be burned.
Do not run the engine if there is a leak.
If you run the engine, it could lose all
coolant. That could cause an engine re,
and you could be burned. Get any leak
xed before you drive the vehicle.If your vehicle has an electric engine cooling
fan, check the coolant temperature gage.
If the coolant temperature is approximately
232°F (111°C), the electric cooling fan should be
running. If it is not, your vehicle needs service.
Turn off the engine.
If your vehicle has an engine-driven cooling fan,
start the engine again and see if the fan speed
increases when idle speed is doubled by pushing
the accelerator pedal down. If it does not, your
vehicle needs service. Turn off the engine.
Notice:Engine damage from running your
engine without coolant is not covered by your
warranty. SeeOverheated Engine Protection
Operating Mode (V8 Engines Only) on page 508
for information on driving to a safe place in
an emergency.
Notice:Using coolant other than DEX-COOL®
may cause premature engine, heater core or
radiator corrosion. In addition, the engine
coolant may require changing sooner, at
30,000 miles (50 000 km) or 24 months,
whichever occurs rst. Any repairs would not
be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your
vehicle.
510

How to Add Coolant to the Coolant
Surge Tank for Gasoline Engines
If your vehicle has a diesel engine, see “Cooling
System” in the DURAMAX®Diesel Supplement for
the proper coolant ll procedure.
If you have not found a problem yet, check to see
if coolant is visible in the surge tank. If coolant
is visible but the coolant level is not at or above
the FULL COLD mark, add a 50/50 mixture
of clean, drinkable water and DEX-COOL
®coolant
at the coolant surge tank, but be sure the
cooling system, including the coolant surge tank
pressure cap, is cool before you do it. SeeEngine
Coolant on page 502for more information.If no coolant is visible in the surge tank, add
coolant as follows:
{CAUTION:
Steam and scalding liquids from a hot
cooling system can blow out and burn
you badly. They are under pressure, and if
you turn the coolant surge tank pressure
cap — even a little — they can come out at
high speed. Never turn the cap when the
cooling system, including the coolant
surge tank pressure cap, is hot. Wait for
the cooling system and coolant surge
tank pressure cap to cool if you ever have
to turn the pressure cap.
511

Power Steering Fluid
SeeEngine
Compartment Overview
on page 480for
reservoir location.
When to Check Power Steering Fluid
It is not necessary to regularly check power
steering uid unless you suspect there is a leak in
the system or you hear an unusual noise. A
uid loss in this system could indicate a problem.
Have the system inspected and repaired.
How to Check Power Steering Fluid
To check the power steering uid, do the following:
1. Turn the key off and let the engine
compartment cool down.
2. Wipe the cap and the top of the reservoir clean.
3. Unscrew the cap and wipe the dipstick with a
clean rag.
4. Replace the cap and completely tighten it.
5. Remove the cap again and look at the
uid level on the dipstick.
The level should be at the FULL COLD mark. If
necessary, add only enough uid to bring the level
up to the mark.
What to Use
To determine what kind of uid to use, see
Recommended Fluids and Lubricants on page 629.
Always use the proper uid. Failure to use the
proper uid can cause leaks and damage hoses
and seals.
515

Windshield Washer Fluid
What to Use
When you need windshield washer uid, be sure
to read the manufacturer’s instructions before
use. If you will be operating your vehicle in an area
where the temperature may fall below freezing,
use a uid that has sufficient protection against
freezing.
Adding Washer Fluid
Your vehicle has a low washer uid message that
comes on when the washer uid is low. The
message is displayed for 15 seconds at the start
of each ignition cycle. When the CHECK WASHER
FLUID message is displayed, you will need to
add washer uid to the windshield washer
uid reservoir.
Open the cap with the
washer symbol on it.
Add washer uid
until the tank is full. See
Engine Compartment
Overview on page 480
for reservoir location.Notice:
When using concentrated washer uid,
follow the manufacturer’s instructions
for adding water.
Do not mix water with ready-to-use washer
uid. Water can cause the solution to
freeze and damage your washer uid tank
and other parts of the washer system.
Also, water does not clean as well
as washer uid.
Fill your washer uid tank only
three-quarters full when it is very cold.
This allows for expansion if freezing
occurs, which could damage the tank if it
is completely full.
Do not use engine coolant (antifreeze) in
your windshield washer. It can damage
your washer system and paint.
516

Brakes
Brake Fluid
Your brake master
cylinder reservoir is
lled with DOT-3 brake
uid. SeeEngine
Compartment Overview
on page 480for the
location of the reservoir.
There are only two reasons why the brake uid
level in the reservoir might go down. The rst
is that the brake uid goes down to an acceptable
level during normal brake lining wear. When
new linings are put in, the uid level goes back
up. The other reason is that uid is leaking out of
the brake system. If it is, you should have your
brake system xed, since a leak means that
sooner or later your brakes will not work well, or
will not work at all.So, it is not a good idea to top off your brake uid.
Adding brake uid will not correct a leak. If you
add uid when your linings are worn, then you will
have too much uid when you get new brake
linings. You should add or remove brake uid,
as necessary, only when work is done on
the brake hydraulic system.
{CAUTION:
If you have too much brake uid, it can
spill on the engine. The uid will burn if
the engine is hot enough. You or others
could be burned, and your vehicle could
be damaged. Add brake uid only when
work is done on the brake hydraulic
system. See “Checking Brake Fluid” in
this section.
Refer to the Maintenance Schedule to determine
when to check your brake uid. SeeScheduled
Maintenance (Gasoline Engine) on page 617.
517

Checking Brake Fluid
You can check the brake uid without taking off
the cap.
Just look at the brake
uid reservoir. The uid
level should be above
MIN. If it is not,
have your brake system
checked to see if
there is a leak.
After work is done on the brake hydraulic system,
make sure the level is above the MIN but not
over the MAX mark.
What to Add
When you do need brake uid, use only DOT-3
brake uid. Use new brake uid from a sealed
container only. SeeRecommended Fluids
and Lubricants on page 629.
Always clean the brake uid reservoir cap and the
area around the cap before removing it. This
will help keep dirt from entering the reservoir.
{CAUTION:
With the wrong kind of uid in your brake
system, your brakes may not work well, or
they may not even work at all. This could
cause a crash. Always use the proper
brake uid.
Notice:
Using the wrong uid can badly damage
brake system parts. For example, just a
few drops of mineral-based oil, such
as engine oil, in your brake system can
damage brake system parts so badly that
they will have to be replaced. Do not
let someone put in the wrong kind of uid.
If you spill brake uid on your vehicle’s
painted surfaces, the paint nish can be
damaged. Be careful not to spill brake
uid on your vehicle. If you do, wash it off
immediately. SeeWashing Your Vehicle on
page 592.
518

Jump Starting
If your vehicle’s battery (or batteries) has run
down, you may want to use another vehicle and
some jumper cables to start your vehicle. Be sure
to use the following steps to do it safely.
{CAUTION:
Batteries can hurt you. They can be
dangerous because:
They contain acid that can burn you.
They contain gas that can explode or
ignite.
They contain enough electricity to
burn you.
If you do not follow these steps exactly,
some or all of these things can hurt you.
Notice:Ignoring these steps could result in
costly damage to your vehicle that would
not be covered by your warranty.Trying to start your vehicle by pushing or
pulling it will not work, and it could damage
your vehicle.
1. Check the other vehicle. It must have a
12-volt battery with a negative ground system.
Notice:If the other vehicle’s system is
not a 12-volt system with a negative ground,
both vehicles can be damaged. Only use
vehicles with 12-volt systems with negative
grounds to jump start your vehicle.
2. If you have a vehicle with a diesel engine
with two batteries (or more), you should
know before you begin that, especially in cold
weather, you may not be able to get enough
power from a single battery in another vehicle
to start your diesel engine.
If your vehicle has more than one battery, use
the battery that is closer to the starter — this
will reduce electrical resistance.
521

{CAUTION:
Fans or other moving engine parts can
injure you badly. Keep your hands away
from moving parts once the engine is
running.
6. Check that the jumper cables do not have
loose or missing insulation. If they do, you
could get a shock. The vehicles could
be damaged too.
Before you connect the cables, here are some
basic things you should know. Positive (+)
will go to positive (+) or a remote positive
terminal (+) if the vehicle has one. Negative (−)
will go to a heavy, unpainted metal engine
part or a remote negative (−) terminal if
the vehicle has one.Do not connect positive (+) to negative (−)or
you will get a short that would damage
the battery and maybe other parts too. And
do not connect the negative (−) cable to
the negative (−) terminal on the dead battery
because this can cause sparks.
On vehicles that have dual batteries, make all
battery connections to the remote positive (+)
and remote negative (−) terminals.
7. Connect the red
positive (+) cable
to the positive (+)
terminal of the
vehicle with the
dead battery. Use a
remote positive (+)
terminal if the vehicle
has one.
524

Rear Axle
When to Check Lubricant
It is not necessary to regularly check rear axle
uid unless you suspect there is a leak or you hear
an unusual noise. A uid loss could indicate a
problem. Have it inspected and repaired.
All axle assemblies are lled by volume of uid
during production. They are not lled to reach
a certain level. When checking the uid level on
any axle, variations in the readings can be caused
by factory ll differences between the minimum
and the maximum uid volume. Also, if a vehicle
has just been driven before checking the uid
level, it may appear lower than normal because
uid has traveled out along the axle tubes and has
not drained back to the sump area. Therefore, a
reading taken ve minutes after the vehicle
has been driven will appear to have a lower uid
level than a vehicle that has been stationary
for an hour or two. Remember that the rear axle
assembly must be supported to get a true reading.
How to Check Lubricant
To get an accurate reading, the vehicle should be
on a level surface.
The proper level for the 1500 Series is from
5/8 inch to 1 5/8 inch (15 mm to 40 mm)
below the bottom of the ller plug hole.
The proper level for the 1500HD Series,
2500 Series and 2500HD Series with the
6.0L V8 engine (RPO LQ4) is from 0 to 1/2 inch
(0 to 13 mm) below the bottom of the ller
plug hole.
1500 Series Shown, 2500 Series Similar
527