engine CHEVROLET CLASSIC 2004 Workshop Manual

GM Goodwrench®oil meets all the requirements for
your vehicle.
If you are in an area of extreme cold, where the
temperature falls below−20°F (−29°C), it is
recommended that you use either an SAE 5W-30
synthetic oil or an SAE 0W-30 oil. Both will provide
easier cold starting and better protection for your engine
at extremely low temperatures.
Engine Oil Additives
Do not add anything to your oil. The recommended oils
with the starburst symbol that meet GM Standard
GM6094M are all you will need for good performance and
engine protection.
When to Change Engine Oil
If any one of these is true for you, use the short trip/city
maintenance schedule:
•Most trips are less than 5 miles (8 km). This is
particularly important when outside temperatures
are below freezing.
•Most trips include extensive idling (such as frequent
driving in stop-and-go traffic).
•You frequently tow a trailer or use a carrier on top
of your vehicle.
•The vehicle is used for delivery service, police, taxi
or other commercial application.Driving under these conditions causes engine oil to
break down sooner. If any one of these is true for your
vehicle, then you need to change your oil and filter
every 3,000 miles (5 000 km) or 3 months — whichever
occurs first.
If none of them is true, use the long trip/highway
maintenance schedule. Change oil and filter every
7,500 miles (12 500 km) or 12 months — whichever
occurs first. Driving a vehicle with a fully warmed engine
under highway conditions will cause engine oil to
break down slower.
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
filter 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.
5-16

Engine Air Cleaner/Filter
The engine air cleaner/filter is located in the engine
compartment on the driver’s side of the vehicle.
SeeEngine Compartment Overview on page 5-12for
more information on location.
When to Inspect the Engine Air
Cleaner/Filter
Inspect the air cleaner/filter every 15,000 miles (25 000
km) and replace every 30,000 miles (50 000 km). If
you are driving in dusty/dirty conditions, inspect the filter
at each engine oil change.
5-17

How to Inspect the Engine Air
Cleaner/Filter
To inspect the air cleaner/filter remove the filter from the
vehicle and lightly shake filter to release loose dust
and dirt. If the filter remains “caked” with dirt, a new filter
is required.
To inspect or replace the engine air cleaner/filter, do the
following:
1. Remove the screws that hold the cover on.
2. Lift off the cover.
3. Check or replace the engine air cleaner/filter.
4. Put the cover back on tightly.
Refer to the Maintenance Schedule to determine when
to replace the air filter.
SeePart A: Scheduled Maintenance Services 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’re driving.
5-18

Automatic Transaxle Fluid
It is not necessary to check the transaxle fluid level. A
transaxle fluid leak is the only reason for fluid loss. If a
leak occurs, take the vehicle to the dealership service
department and have it repaired as soon as possible. You
may also have your fluid level checked by your dealer or
service center when you have your oil changed.
Change both the fluid and filter 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, the fluid and filter do not require changing.
Notice:Use of automatic transaxle uid labeled
other than DEXRON
®-III may damage your vehicle,
and the damages may not be covered by your
warranty. Always use DEXRON
®-III labeled automatic
transaxle uid.
Engine Coolant
The cooling system in your vehicle is filled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs first, if you add
only DEX-COOL
®extended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem with
engine overheating, seeEngine Overheating on
page 5-22.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
•Give freezing protection down to−34°F (−37°C).
•Give boiling protection up to 265°F (129°C).
•Protect against rust and corrosion.
•Help keep the proper engine temperature.
•Let the warning lights and gages work as they
should.
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.
5-19

What to Use
Use a mixture of one-halfclean, drinkable waterand
one-half DEX-COOL®coolant which won’t damage
aluminum parts. If you use this coolant mixture,
you don’t need to add anything else.
{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.Notice:If you use an improper coolant mixture,
your engine could overheat and be badly damaged.
The repair cost wouldn’t be covered by your
warranty. Too much water in the mixture can freeze
and crack the engine, radiator, heater core and
other parts.
If you have to add coolant more than four times a year,
have your dealer check your cooling system.
Notice:If you use the proper coolant, you don’t
have to add extra inhibitors or additives which claim
to improve the system. These can be harmful.
5-20

Checking Coolant
The engine coolant surge tank is located in the engine
compartment on the passenger’s side of the vehicle.
SeeEngine Compartment Overview on page 5-12
for more information on location.
{CAUTION:
Turning the surge tank pressure cap when the
engine and radiator are hot can allow steam
and scalding liquids to blow out and burn you
badly. Never turn the surge tank pressure
cap — even a little — when the engine and
radiator are hot.
The vehicle must be on a level surface. When your
engine is cold, the coolant level should be at the FULL
COLD mark or slightly higher.
If the low coolant light
comes on and stays on, it
means you’re low on
engine coolant.
SeeLow Coolant Warning Light on page 3-29for more
information.
5-21

Adding Coolant
If you need more coolant, add the proper DEX-COOL®
coolant mixtureat the surge tank,but only when the
engine is cool. If the surge tank is empty, a special fill
procedure is necessary. SeeEngine Overheating
on page 5-22andCooling System on page 5-25.
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol,
and it will burn if the engine parts are hot
enough. Don’t spill coolant on a hot engine.
When replacing the pressure cap, make sure it is
hand-tight.
Coolant Surge Tank Pressure Cap
Notice:If the pressure cap is not tightly installed,
coolant loss and possible engine damage may
occur. Be sure the cap is properly and tightly
secured.
Engine Overheating
You will find a coolant temperature gage and a low
coolant level warning light on your vehicle’s instrument
panel. SeeEngine Coolant Temperature Gage on
page 3-29andLow Coolant Warning Light on page 3-29.
5-22

If Steam Is Coming From Your Engine
{CAUTION:
Steam from an overheated engine can burn
you badly, even if you just open the hood. Stay
away from the engine if you see or hear steam
coming from it. Just turn it off and get
everyone away from the vehicle until it cools
down. Wait until there is no sign of steam or
coolant before you open the hood.
If you keep driving when your engine is
overheated, the liquids in it can catch re. You
or others could be badly burned. Stop your
engine if it overheats, and get out of the
vehicle until the engine is cool.
Notice:If your engine catches re because you
keep driving with no coolant, your vehicle can
be badly damaged. The costly repairs would not be
covered by your warranty.
5-23

If No Steam Is Coming From Your
Engine
An overheat warning, along with a low coolant light, can
indicate a serious problem. SeeLow Coolant Warning
Light on page 3-29.
If you get an engine overheat warning with no low
coolant light, 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, 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.
You may decide not to lift the hood but to get service
help right away.
5-24

Cooling System
When you decide it’s safe to lift the hood, here’s what
you’ll see:
A. Coolant Surge Tank with Pressure Cap
B. Electric Engine Cooling Fan{CAUTION:
An electric engine cooling fan under the hood
can start up even when the engine is not
running and can injure you. Keep hands,
clothing and tools away from any underhood
electric fan.
If the coolant inside the coolant surge tank is boiling,
don’t do anything else until it cools down. The vehicle
should be parked on a level surface.
5-25