engine CHEVROLET IMPALA 2003 8.G Repair Manual

Fuel
Use of the recommended fuel is an important part of the
proper maintenance of your vehicle.
Gasoline Octane
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 hear heavy knocking, your engine needs service.
Gasoline Speci®cations
It is recommended that gasoline meet speci®cations
which were developed by the American Automobile
Manufacturers Association and endorsed by the
Canadian Vehicle Manufacturers Association for better
vehicle performance and engine protection. Gasoline
meeting these speci®cations could provide improved
driveability and emission control system performance
compared to other gasoline.
In Canada, look for the
ªAuto Makers' Choiceº
label on the pump.
Canada Only
5-5

California Fuel
If your vehicle is certi®ed to meet California Emission
Standards (see the underhood emission control label), it
is designed to operate on fuels that meet California
speci®cations. If this fuel is not available in states
adopting California emissions standards, your vehicle
will operate satisfactorily on fuels meeting federal
speci®cations, but emission control system performance
may be affected. The malfunction indicator lamp may
turn on (see
Malfunction Indicator Lamp on page 3-37)
and your vehicle may fail a smog-check test. If this
occurs, return to your authorized GM dealer for
diagnosis. If it is determined that the condition is caused
by the type of fuel used, repairs may not be covered
by your warranty.
Additives
To provide cleaner air, all gasolines in the United States
are now required to contain additives that will help
prevent engine and fuel system deposits from forming,
allowing your emission control system to work
properly. You should not have to add anything to your
fuel. Gasolines containing oxygenates, such as
ethers and ethanol, and reformulated gasolines may be
available in your area to contribute to clean air.
General Motors recommends that you use these
gasolines, particularly if they comply with the
speci®cations described earlier.
Notice:Your vehicle was not designed for fuel that
contains methanol. Don't use fuel containing
methanol. It can corrode metal parts in your fuel
system and also damage the plastic and rubber
parts. That damage wouldn't 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 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 wouldn't 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'll be driving.
5-6

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.
Hood Release
To open the hood, do the following:
1. Pull the handle located
inside the vehicle near
the parking brake
pedal.
5-10

Engine Compartment Overview
When you open the hood on the 3400 V6 (Code E) engine, you'll see the following:
5-12

A. Windshield Washer Fluid Reservoir. SeeWindshield
Washer Fluid on page 5-44.
B. Battery. See
Battery on page 5-48.
C. Remote Positive (+) Terminal. See
Jump Starting on
page 5-49.
D. Upper Underhood Fuse Block. See ªUpperhood
Fuse Block (Upper)º under
Fuses and Circuit
Breakers on page 5-95.
E. Lower Underhood Fuse Block. See ªUnderhood
Fuse Block (Lower)º under
Fuses and Circuit
Breakers on page 5-95.
F. Radiator Pressure Cap. See
Radiator Pressure Cap
on page 5-30.
G. Engine Coolant Recovery Tank. See
Cooling System
on page 5-33.
H. Power Steering Fluid Reservoir. See
Power Steering
Fluid on page 5-43.I. Electric Cooling Fan. See
Cooling System on
page 5-33.
J. Engine Oil Fill Cap. See ªChecking Engine Oilº
under
Engine Oil on page 5-16.
K. Engine Oil Dipstick. See ªChecking Engine Oilº
under
Engine Oil on page 5-16.
L. Bleed Valves (underneath engine shield). See ªHow
to Add Coolant to the Radiatorº under
Cooling
System on page 5-33.
M. Transaxle Fluid Dipstick. See
Automatic Transaxle
Fluid on page 5-24.
N. Brake Master Cylinder Reservoir. See
Brakes on
page 5-45.
O. Engine Air Cleaner/Filter. See
Engine Air
Cleaner/Filter on page 5-22.
5-13

When you open the hood on the 3800 V6 (Code K) engine, you'll see the following:
5-14

A. Windshield Washer Fluid Reservoir. SeeWindshield
Washer Fluid on page 5-44.
B. Battery. See
Battery on page 5-48.
C. Remote Positive (+) Terminal. See
Jump Starting on
page 5-49.
D. Upper Underhood Fuse Block. See ªUpperhood
Fuse Block (Upper)º under
Fuses and Circuit
Breakers on page 5-95.
E. Lower Underhood Fuse Block. See ªUnderhood
Fuse Block (Lower)º under
Fuses and Circuit
Breakers on page 5-95.
F. Radiator Pressure Cap. See
Radiator Pressure Cap
on page 5-30.
G. Engine Coolant Recovery Tank. See
Cooling System
on page 5-33
H. Power Steering Fluid Reservoir (low in engine
compartment). SeePower Steering Fluid on
page 5-43.I. Electric Cooling Fan. See
Cooling System on
page 5-33.
J. Engine Oil Dipstick. See ªChecking Engine Oilº
under
Engine Oil on page 5-16.
K. Engine Oil Fill Cap. See ªChecking Engine Oilº
under
Engine Oil on page 5-16.
L. Bleed Valves (underneath engine shield). See ªHow
to Add Coolant to the Radiatorº under
Cooling
System on page 5-33.
M. Transaxle Fluid Dipstick. See
Automatic Transaxle
Fluid on page 5-24.
N. Brake Master Cylinder Reservoir. See
Brakes on
page 5-45.
O. Engine Air Cleaner/Filter. See
Engine Air
Cleaner/Filter on page 5-22.
5-15

Engine Oil
Checking Engine Oil
It's 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 the yellow loop located
near the front of the engine. See
Engine Compartment
Overview on page 5-12for more information on location.
Turn off the engine and give the oil several minutes to
drain back into the oil pan. If you don't, the oil
dipstick might not show the actual level.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.
3400 (Code E) V6
Engine
3800 (Code K) Engine
3400 (Code E) V6 Engine
3800 (Code K) V6 Engine
5-16

When to Add Engine Oil
If the oil is at or below the cross-hatched area at the tip
of the dipstick, then you'll need to add at least one
quart of oil. But you must use the right kind. This part
explains what kind of oil to use. For engine oil crankcase
capacity, see
Capacities and Speci®cations on
page 5-103.
Notice:Don't add too much oil. If your engine has
so much oil that the oil level gets above the
cross-hatched area that shows the proper operating
range, your engine could be damaged.
The engine oil ®ll cap is located toward the front of the
engine near the yellow-looped engine oil dipstick
handle. See
Engine Compartment Overview on
page 5-12for more information on location.
Be sure to ®ll it enough to put the level somewhere in
the proper operating range in the cross-hatched
area. Push the dipstick all the way back in when
you're through.3400 (Code E) V6
Engine
3800 (Code K) V6
Engine
5-17

What Kind of Engine Oil to Use
Oils recommended for your vehicle can be identi®ed by
looking for the starburst symbol.
This symbol indicates that the oil has been certi®ed by
the American Petroleum Institute (API). Do not use
any oil which does not carry this starburst symbol.
If you choose to perform
the engine oil change
service yourself, be sure
the oil you use has
the starburst symbol on
the front of the oil
container. If you have your
oil changed for you, be
sure the oil put into
your engine is American
Petroleum Institute certi®ed
for gasoline engines.
You should also use the proper viscosity oil for your
vehicle, as shown in the viscosity chart.
3400 (Code E) V6 Engine
5-18