engine CHEVROLET IMPALA 2002 8.G Repair Manual

5-10
Towing Your Vehicle
Consult your dealer or a professional towing service
if you need to have your disabled vehicle towed.
See ªRoadside Assistanceº in the Index. If you
want to tow your vehicle behind another vehicle for
recreational purposes (such as behind a motorhome),
see ªRecreational Vehicle Towingº in the Index.
Engine Overheating
You will find a coolant temperature gage and a warning
message about a hot engine on your instrument panel
cluster. See ªEngine Coolant Temperature Gageº and
ªHot Coolant Temperature Messageº in the Index.
You also have a low coolant message on your instrument
panel cluster. See ªLow Coolant Level Messageº in
the Index.
Overheated Engine Protection
Operating Mode
This emergency operating mode allows your vehicle
to be driven to a safe place in an emergency situation.
If an overheated engine condition exists, an overheat
protection mode which alternates firing groups of
cylinders helps prevent engine damage. In this mode,
you will notice a significant loss in power and engine
performance. The low coolant light may come on and
the temperature gage will indicate an overheat condition
exists. 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. See ªEngine Oilº in the Index.

5-11 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.
CAUTION: (Continued)
CAUTION: (Continued)
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 fire.
You or others could be badly burned. Stop
your engine if it overheats, and get out of the
vehicle until the engine is cool. See ªOverheated
Engine Protection Operating Modeº in the
Index for information on driving to a safe
place in an emergency.
NOTICE:
If your engine catches fire because you keep driving
with no coolant, your vehicle can be badly damaged.
The costly repairs would not be covered by your
warranty. See ªOverheated Engine Protection
Operating Modeº in the Index for information
on driving to a safe place in an emergency.

5-12 If No Steam Is Coming From Your Engine
An overheat warning along with a low coolant message
can indicate a serious problem. See ªLow Coolant
Messageº in the Index.
If you get an engine overheat warning with no low
coolant message, 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. If your air conditioner is on, turn it off.
2. Turn on your heater to full hot at the highest fan
speed and open the window as necessary.
3. If you're in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving
-- AUTOMATIC OVERDRIVE (D).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 vehicle until it cools down. Also, see ªOverheated
Engine Protection Operating Modeº listed previously in
this section.
You may decide not to lift the hood but to get service
help right away.

5-13
Cooling System
When you decide it's safe to lift the hood, here's what
you'll see:
3400 V6 Engine
A. Engine Coolant Recovery Tank
B. Electric Engine Cooling Fans
3800 V6 Engine
A. Engine Coolant Recovery Tank
B. Electric Engine Cooling Fans

5-14
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 recovery tank is boiling,
don't do anything else until it cools down. The vehicle
should be parked on a level surface.
The coolant level should be at or above the COLD mark
on the coolant recovery tank. To check the coolant level,
look for the COLD mark on the side of the coolant
recovery tank that faces the engine. If the coolant level
is not at or above the COLD mark, If it isn't, 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.

5-15
CAUTION:
Heater and radiator hoses, and other engine
parts, can be very hot. Don't touch them. If you
do, you can be burned.
Don't run the engine if there is a leak. If you run
the engine, it could lose all coolant. That could
cause an engine fire, and you could be burned.
Get any leak fixed before you drive the vehicle.
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 isn't covered by your warranty.
See ªOverheated Engine Protection Operating
Modeº in the Index for information on driving to
a safe place in an emergency.
NOTICE:
When adding coolant, it is important that you
use only DEX
-COOL
(silicate-free) coolant.
If coolant other than DEX-COOL is added to
the system, premature engine, heater core or
radiator corrosion may result. In addition, the
engine coolant will require change sooner
-- at
30,000 miles (50 000 km) or 24 months,
whichever occurs first. Damage caused by the
use of coolant other than DEX
-COOL
is not
covered by your new vehicle warranty.

5-16 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 of clean,
drinkable water and DEX
-COOL
engine coolant at the
coolant recovery tank. See ªEngine Coolantº in the
Index for more information.
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 wouldn't
get the overheat warning. Your engine could
catch fire and you or others could be burned.
Use a 50/50 mixture of clean, drinkable water
and DEX
-COOL
coolant.
NOTICE:
In cold weather, water can freeze and crack
the engine, radiator, heater core and other parts.
Use the recommended coolant and the proper
coolant mixture.
The coolant recovery tank is located in the rear of the
engine compartment on the passenger's side of the
vehicle. See ªEngine Compartment Overviewº in the
Index for more information on location.

5-17
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 the coolant in the coolant recovery tank is at the
COLD mark, start your vehicle.
If the overheat warning continues, there's one more
thing you can try. You can add the proper coolant
mixture directly to the radiator, but be sure the cooling
system is cool before you do it.
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 radiator
pressure cap
-- even a little -- they can come out
at high speed. Never turn the cap when the
CAUTION: (Continued)
CAUTION: (Continued)
cooling system, including the radiator pressure
cap, is hot. Wait for the cooling system and
radiator pressure cap to cool if you ever have
to turn the pressure cap.

5-18 How to Add Coolant to the Radiator
NOTICE:
Your engine has a specific radiator fill procedure.
Failure to follow this procedure could cause your
engine to overheat and be severely damaged.
The radiator pressure cap is located in the front of the
engine compartment near the diagonal cross brace on the
passenger's side of the vehicle. See ªEngine Compartment
Overviewº in the Index for more information on location.You can remove the radiator pressure cap when the
cooling system, including the radiator pressure cap and
upper radiator hose, is no longer hot.
1. Turn the pressure cap slowly counterclockwise until
it first stops. (Don't press down while turning the
pressure cap.)
If you hear a hiss, wait for that to stop. A hiss means
there is still some pressure left.2. Then keep turning the pressure cap, but now push
down as you turn it. Remove the pressure cap.

5-19
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.
3. If you have the 3800 V6 engine, remove the 3800
Series II V6 engine cover shield to access the bleed valve.
A. Clean the area around the engine oil fill tube and
cap before removing. Twist the oil fill tube, with
cap attached, counterclockwise and remove it.
B. Lift the engine cover shield at the front, slide the
catch tab out of the engine bracket and remove
the cover shield.
C. Put the oil fill tube, with cap attached, in the valve
cover oil fill hole until you're ready to replace the
cover shield.