engine coolant CHEVROLET CORVETTE 2002 5.G User Guide

3-3
(Defog): This setting divides the air between the
windshield and lower outlets with a small amount of air
directed toward the side window vents. This is useful
when fog appears on the windshield or side glass due to
rain or snowy conditions.
(Defrost): Use this setting to quickly remove fog or
frost from the windshield. This setting directs most of
the airflow to the windshield with a small amount of air
directed toward the lower and side window outlets.
Mode Buttons
These buttons control the air intake, the air conditioning
and the rear window defogger operation.
(Outside Air): Press this button and it will bring
outside air into the vehicle. The light on the button will
come on when operating. Use this setting while trying to
defrost or defog windows to help clear moisture.
(Recirculate): Press this button to limit the amount
of outside air entering the vehicle by recirculating most
of the air inside the vehicle. The light on the button will
come on when operating. This setting is helpful when
you are trying to cool the air quickly or to limit odors
entering the vehicle. Recirculate cannot be used while in
the defrost or defog modes.Operating the system in the recirculation mode may
cause fogging of the vehicle's windows when the
weather is cold and damp. To clear the fog, switch the
system to either the defog or defrost mode and increase
the fan speed. To avoid re
-fogging of the windows,
operate the system in the outside air mode.
A/C (Air Conditioning): This button turns the
air conditioning compressor off or on under most
conditions. The light on the A/C button comes on
when the compressor is operating. The air conditioning
does not operate at temperatures below approximately
35
F to 40
F (2
C to 4
C). The air conditioning
cools and dehumidifies the air coming into the vehicle.
The air conditioning cannot be turned off in defrost,
as it helps to remove moisture from the vehicle. It also
helps to keep the windows clear.
The air conditioning may be forced off at high engine
speeds or high engine oil or coolant temperatures.
See ªRear Window Defoggerº later in this section for
more information.

3-6
A Typical Cold Weather Example:
Your vehicle has been parked outside overnight in
cold weather (below 32
F/ 0
C) and you have set the
driver temperature at 73
F (23
C) and have selected
the AUTO mode. The system will automatically adjust
the temperature output to maximum heating. The fan
will start at a low speed. This is to avoid blowing cold
air into the vehicle. The length of the delay depends on
the amount of time since the engine was last started, the
outside temperature and the engine coolant temperature.
As the coolant warms up, the fan speed will gradually
increase. Air will flow to the floor with some air to
the windshield to prevent fogging under most
normal conditions.
As the interior of the vehicle warms up to the set
temperature, the fan speed will decrease and the
temperature output may become cooler. If the interior
temperature continues to warm up due to heating from
the sun or outside temperature increases, the system
may switch to other air delivery modes (typically defog
or bi
-level).A Typical Hot Weather Example:
The vehicle has been parked outside all day in hot
weather (above 80
F/ 27
C) and you have set the
driver temperature at 73
F (23
C) and have selected the
AUTO mode. The system will automatically adjust the
temperature output to maximum cooling. The fan will
start at a low speed momentarily to push the hot air to
the floor of the vehicle and then go to a higher fan speed
with cold airflow out of the instrument panel outlets.
A small amount of airflow will continue through the
lower ducts to cool the floor area.
The air intake may start in the recirculated mode for
maximum cooling performance. As the interior of the
vehicle cools down to the set temperature, the fan speed
will decrease and the temperature output may become
warmer. The air intake may shift from recirculation to
outside air mode. If the interior continues to cool due to a
decrease in the amount of heat the vehicle is absorbing
from the sun or a decrease in the outside temperature, the
system could switch to other air delivery modes (typically
bi-level or defog).

3-8
Function Buttons
These buttons control the climate control ON/OFF,
air intake, front defrost, rear defrost and the air
conditioning operation.
OFF: Press the OFF button to turn off the climate
control system. This is the only setting that fully
shuts off the fan. The digital display will show only the
outside temperature. You can still adjust the driver set
temperature, the passenger temperature offset and the
air intake mode while in OFF.
A/C (Air Conditioning): This button turns
the air conditioning compressor off or on under most
conditions. The light on the A/C button will come on
when the compressor is operating in either the automatic
or manual mode. The air conditioning does not operate
at temperatures below approximately 35
F to 40
F
(2
C to 4
C). The light on the A/C button will flash if
pressed when air conditioning is not available. The air
conditioning cools and dehumidifies the air coming into
the vehicle. The air conditioning cannot be turned off in
defrost and defog, as it helps to remove moisture from
the vehicle. It also helps to keep the windows clear.If the system is operating in the AUTO mode, turning
the air conditioning off will delete AUTO from the
digital display and show current mode and fan settings.
The AUTO button must be pressed to return to the
automatic mode operation.
The air conditioning may be forced off at high engine
speeds or high engine oil or coolant temperatures.
(Outside Air): Press this button to provide outside
air. The light on this air intake button will come on to
show when it is operating. When in the AUTO mode,
the system automatically selects outside air instead of
recirculate, as required, to control the temperature in the
vehicle. By pressing outside air, the system will lock
into the outside air mode. Any adjustment to the air
intake must then be made manually. Outside air should
be used when trying to defrost or defog windows to help
reduce moisture inside of the vehicle.

3-11 Air Conditioning
On very hot days, the vehicle will cool down more
quickly and economically if you open the windows
long enough to let hot inside air escape. Then keep the
windows closed in order to allow the air conditioning
to work best. Maximum cooling will occur when the
recirculate setting is operating, airflow direction is in the
upper mode, and the temperature control knob (on a
manual climate control system) is turned all the way to
the blue area. These settings will be selected by the
automatic electronic dual climate control system if
operating in AUTO when maximum cooling is required.
When the air conditioning is on, you may sometimes
notice slight changes in the vehicle's engine performance
and power. This is normal. The system is designed to
help fuel economy while maintaining the desired
cooling level.
The air conditioning removes moisture from the air,
so you may notice water dripping from under the
vehicle when it is idling or after it has been turned off.
This is normal.
Heating
The heater works best if you keep the windows closed.
Maximum heating will occur when airflow direction is
in the lower mode and the temperature control knob
(on a manual climate control system) is all the way in
the red area. These settings will be selected by the
automatic electronic dual climate control system if
operating in AUTO when maximum heating is required.
The bi
-level setting is designed for use on sunny days
when the air is only moderately warm or cool. On days
like these, the sun may adequately warm your upper
body, but your lower body may not be warm enough.
The bi
-level setting will direct cooler airflow to your
upper body and warmer air to the floor area.
If you have the optional engine coolant heater and use it
during cold weather 0
F (
-18
C) or lower, the heating
system will provide heat more quickly because the
coolant is already warmed. See ªEngine Coolant Heaterº
in the Index.

5-9
Engine Overheating
You will find an engine coolant temperature gage on the
instrument panel cluster and a COOLANT OVER
TEMP message on the Driver Information Center (DIC).
See ªEngine Coolant Temperature Gageº and ªCoolant
Over Temp DIC Messageº in the Index.
Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the messages
COOLANT OVER TEMP and REDUCED ENGINE
POWER are displayed, along with the Check Engine
light, an overheat protection mode which alternates
firing groups of cylinders helps prevent engine damage. In this mode, you will notice a loss in power and engine
performance. This operating mode allows your vehicle to
be driven to a safe place in an emergency; you may drive
up to 50 miles (80 km).
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.

5-10 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 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.

5-11
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.
If No Steam Is Coming From Your Engine
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.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 (
)
or THIRD (3) for automatic transmissions.
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.

5-12
Cooling System
When you decide it's safe to lift the hood, here's what
you'll see:
A. Electric Engine Cooling Fans
B. Coolant Surge Tank
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.

5-13
The coolant level should be at or above the FULL 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.
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.

5-14
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.
How to Add Coolant to the Coolant
Surge Tank
If you haven't found a problem yet, check to see if
coolant is visible in the surge tank. If coolant is visible
but the coolant level isn't at the FULL COLD mark on
the coolant surge tank, 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. See ªEngine Coolantº in the Index
for more information.