service CHEVROLET IMPALA 2004 8.G Workshop Manual

Doing Your Own Service Work
If you want to do some of your own service work, you
will want to use the proper service manual. It tells
you much more about how to service your vehicle than
this manual can. To order the proper service manual,
seeService Publications Ordering Information on
page 7-12.
Your vehicle has an air bag system. Before attempting
to do your own service work, seeServicing Your
Air Bag-Equipped Vehicle on page 1-60.
You should keep a record with all parts receipts and list
the mileage and the date of any service work you
perform. SeeMaintenance Record on page 6-15.
{CAUTION:
You can be injured and your vehicle could be
damaged if you try to do service work on a
vehicle without knowing enough about it.
CAUTION: (Continued)
CAUTION: (Continued)

Be sure you have sufficient knowledge,
experience, the proper replacement parts
and tools before you attempt any vehicle
maintenance task.
Be sure to use the proper nuts, bolts and
other fasteners. “English” and “metric”
fasteners can be easily confused. If you
use the wrong fasteners, parts can later
break or fall off. You could be hurt.
Adding Equipment to the Outside
of Your Vehicle
Things you might add to the outside of your vehicle can
affect the airow around it. This may cause wind
noise and affect windshield washer performance.
Check with your dealer before adding equipment to the
outside of your vehicle.
5-4

Fuel
Use of the recommended fuel is an important part of the
proper maintenance of your vehicle.
Gasoline Octane
If your vehicle has the 3400 V6 engine (VIN Code E) or
the 3800 V6 engine (VIN Code K), use regular
unleaded gasoline with a posted octane of 87 or higher.
If the octane is less than 87, you may get a heavy
knocking noise when you drive. If this occurs, use a
gasoline rated at 87 octane or higher as soon as
possible. Otherwise, you might damage your engine.
A little pinging noise when you accelerate or drive uphill
is considered normal. This does not indicate a problem
exists or that a higher-octane fuel is necessary. If
you are using 87 octane or higher-octane fuel and you
hear heavy knocking, your engine needs service.
If your vehicle has the 3800 Supercharged V6 engine
(VIN Code 1), use only premium unleaded gasoline with a
posted octane of 91 or higher. In an emergency, you may
be able to use a lower octane — as low as 87 — if heavy
knocking does not occur. Rell your tank with premium
fuel as soon as possible. Otherwise, you might damage
your engine. If you are using 91 octane or higher-octane
fuel and you hear heavy knocking, your engine needs
service.
Gasoline Specications
It is recommended that gasoline meet specications
which were developed by automobile manufacturers
around the world and contained in the World-Wide
Fuel Charter which is available from the
Alliance of Automobile Manufacturers at
www.autoalliance.org/fuel_charter.htm. Gasoline
meeting these specications could provide improved
driveability and emission control system performance
compared to other gasoline.
In Canada, look for the
“Auto Makers’ Choice”
label on the pump.
Canada Only
5-5

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 does
not recommend 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.
Fuels in Foreign Countries
If you plan on driving in another country outside the
United States or Canada, the proper fuel may be hard
to nd. Never use leaded gasoline or any other fuel
not recommended in the previous text on fuel.
Costly repairs caused by use of improper fuel would
not be covered by your warranty.
To check the fuel availability, ask an auto club, or
contact a major oil company that does business in the
country where you will be driving.
Filling Your 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.
5-7

When to Change Engine Oil
(GM Oil Life System)
Your vehicle has a computer system that lets you know
when to change the engine oil and lter. This is based on
engine revolutions and engine temperature, and not on
mileage. Based on driving conditions, the mileage at
which an oil change will be indicated can vary
considerably. For the oil life system to work properly, you
must reset the system every time the oil is changed.
When the system has calculated that oil life has been
diminished, it will indicate that an oil change is
necessary. A CHANGE ENGINE OIL message will
come on. Change your oil as soon as possible within
the next two times you stop for fuel. It is possible that, if
you are driving under the best conditions, the oil life
system may not indicate that an oil change is necessary
for over a year. However, your engine oil and lter
must be changed at least once a year and at this time
the system must be reset. Your dealer has GM-trained
service people who will perform this work using
genuine GM parts and reset the system. It is also
important to check your oil regularly and keep it at the
proper level.
If the system is ever reset accidentally, you must
change your oil at 3,000 miles (5 000 km) since your
last oil change. Remember to reset the oil life system
whenever the oil is changed.
How to Reset the CHANGE ENGINE OIL
Message
The GM Oil Life System calculates when to change
your engine oil and lter based on vehicle use.
Anytime your oil is changed, reset the system so it can
calculate when the next oil change is required. If a
situation occurs where you change your oil prior to a
CHANGE ENGINE OIL message being turned on, reset
the system.
After changing the engine oil, the system must be reset.
To reset the CHANGE ENGINE OIL message use
one of the following procedures:
Using the Radio
1. Turn the ignition to ACC or ON, with the radio off.
2. Press and hold the TUNE DISP knob on the
radio for at least ve seconds until SETTINGS
is displayed.
3. Press the SEEK PSCAN up or down arrow to scroll
through the main menu.
4. Scroll until OIL LIFE appears on the display.
5. Press the 1 PREV or 2 NEXT buttons to enter the
submenu. RESET will be displayed.
5-22

6. Press the TUNE DISP knob to reset. A chime will
be heard to verify the new setting and DONE will
be displayed for one second.
7. Once the indicator has been reset, scroll until EXIT
appears on the display.
8. Press the TUNE DISP knob to exit programming.
A chime will be heard to verify the exit.
9. Turn the key to OFF.
If the CHANGE ENGINE OIL message comes back on
when you start your vehicle, the engine oil life system
has not reset. Repeat the procedure.
Using the Accelerator Pedal
1. Turn the ignition to ON, with the engine off.
2. Fully press and release the accelerator pedal slowly
three times within ve seconds. If the CHANGE
ENGINE OIL message ashes, the system is reset.
However, if it stays on, it did not reset. Repeat
the procedure.
3. Turn the key to OFF.
If the CHANGE ENGINE OIL message comes back on
when you start your vehicle, the engine oil life system
has not reset. Repeat the procedure.
What to Do with Used Oil
Used engine oil contains certain elements that may be
unhealthy for your skin and could even cause cancer.
Do not let used oil stay on your skin for very long.
Clean your skin and nails with soap and water, or a
good hand cleaner. Wash or properly dispose of
clothing or rags containing used engine oil. See the
manufacturer’s warnings about the use and disposal of
oil products.
Used oil can be a threat to the environment. If you
change your own oil, be sure to drain all the oil from the
lter before disposal. Never dispose of oil by putting it
in the trash, pouring it on the ground, into sewers, or into
streams or bodies of water. Instead, recycle it by
taking it to a place that collects used oil. If you have a
problem properly disposing of your used oil, ask
your dealer, a service station or a local recycling center
for help.
5-23

Supercharger Oil
Unless you are technically
qualied and have the
proper tools, you should let
your dealer or a qualied
service center perform
this maintenance.
When to Check
Check oil level every 30,000 miles (50 000 km) or every
36 months, whichever occurs rst.
What Kind of Oil to Use
Use only the recommended supercharger oil. See
Recommended Fluids and Lubricants on page 6-12.
How to Check and Add Oil
Park the vehicle on a level surface. Check oil only when
the engine is cold. Allow the engine to cool two to
three hours after running.
{CAUTION:
If you remove the supercharger oil ll plug
while the engine is hot, pressure may cause
hot oil to blow out of the oil ll hole. You may
be burned. Do not remove the plug until the
engine cools.
1. Clean the area around the oil ll plug before
removing it.
2. Remove the oil ll plug.
3. The oil level is correct when it just reaches the
bottom of the threads of the inspection hole.
4. Replace the oil plug with the O-ring in place.
Tighten to 88 lb-in (10Y).
5-24

5. To reinstall the cover, position the tabs through the
slots on the housing. A notch on the sides of the
lter cover will indicate the correct engagement.
Reinstall the two clips on the top of the housing
when you are nished.
Refer to the Maintenance Schedule to determine when
to replace the air lter.
SeeScheduled Maintenance on page 6-4.
{CAUTION:
Operating the engine with the air cleaner/lter off
can cause you or others to be burned. The air
cleaner not only cleans the air, it helps to stop
ame if the engine backres. If it is not there
and the engine backres, you could be burned.
Do not drive with it off, and be careful working
on the engine with the air cleaner/lter off.
Notice:If the air cleaner/lter is off, a backre can
cause a damaging engine re. And, dirt can easily
get into your engine, which will damage it. Always
have the air cleaner/lter in place when you are
driving.
Automatic Transaxle Fluid
When to Check and Change
A good time to check your automatic transaxle uid
level is when the engine oil is changed.
Change both the uid and lter every 50,000 miles
(83 000 km) 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.
If you do not use your vehicle under any of these
conditions, change the uid and lter at 100,000 miles
(166 000 km).
SeeScheduled Maintenance on page 6-4.
5-26

How to Check
Because this operation can be a little difficult, you may
choose to have this done at the dealership service
department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading on the dipstick.
Notice:Too much or too little uid can damage the
transaxle. Too much can mean that some of the uid
could come out and fall on hot engine or exhaust
system parts, starting a re. Too little uid could
cause the transaxle to overheat. Be sure to get an
accurate reading if you check the transaxle uid.
Wait at least 30 minutes before checking the transaxle
uid level if you have been driving:
When outside temperatures are above 90°F (32°C).
At high speed for quite a while.
In heavy traffic – especially in hot weather.
While pulling a trailer.To get the right reading, the uid should be at normal
operating temperature, which is 180°F to 200°F
(82°C to 93°C).
Get the vehicle warmed up by driving about
15 miles (24 km) when outside temperatures are above
50°F (10°C). If it’s colder than 50°F (10°C), you may
have to drive longer.
Checking the Fluid Level
Prepare your vehicle as follows:
Park your vehicle on a level place. Keep the engine
running.
With the parking brake applied, place the shift lever
in PARK (P).
With your foot on the brake pedal, move the shift
lever through each gear range, pausing for about
three seconds in each range. Then, position the shift
lever in PARK (P).
Let the engine run at idle for three to ve minutes.
5-27

If No Steam Is Coming From
Your Engine
An overheat warning along with a low coolant message
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.
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. 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.
2. Turn on your heater to full hot at the highest fan
speed and open the window as necessary.If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning doesn’t come back on, you can drive
normally.
If the warning continues, pull over, stop, and park your
vehicle right away.
If there’s still no sign of steam, you can idle the engine
for three minutes while you’re 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” listed
previously in this section.
You may decide not to lift the hood but to get service
help right away.
5-34

If there seems to be no leak, with the engine on, check
to see if the electric engine cooling fans are running.
If the engine is overheating, both fans should be
running. If they aren’t, your vehicle needs service.
Notice:Engine damage from running your engine
without coolant is not covered by your warranty. See
“Overheated Engine Protection Operating Mode”
in the Index 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.
How to Add Coolant to the Coolant
Recovery Tank
If you haven’t found a problem yet, but the coolant level
isn’t at the COLD mark, add a 50/50 mixture ofclean,
drinkable waterand DEX-COOL
®engine coolant at
the coolant recovery tank. SeeEngine Coolant on
page 5-29
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil
before the proper coolant mixture will. Your
vehicle’s coolant warning system is set for the
proper coolant mixture. With plain water or the
wrong mixture, your engine could get too hot
but you would not get the overheat warning.
Your engine could catch re and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.
5-37