engine coolant CHEVROLET CORVETTE 2000 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.
FRESH 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 fresh 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: 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.

3-5
When adjusting the temperature, start with a driver-set
temperature of 73
F (23
C) until you determine your
comfort zone. If you choose 60
F (16
C), the
system will remain at maximum cooling and will not
automatically adjust fan speed or air delivery. If you
choose 90
F (32
C), the system will remain at
maximum heating and will not automatically adjust fan
speed or air delivery. Choosing either maximum setting
will not cause the system to heat or cool any faster.
Turning the knob past either maximum setting has no
effect on the operation of the system.
Passenger Temperature Offset
The PASSENGER knob changes the temperature on the
passenger's side of the vehicle. When the knob is in
the 12 o'clock position, the passenger's temperature is
the same as the driver's. Turn the knob clockwise for
warmer air on the passenger's side, counterclockwise
for cooler air. If the driver
-set temperature is set at 60
F
(16
C) or 90
F (32
C), turning the passenger knob
has no effect because the system is locked at a
maximum setting.Automatic Operation
Press the AUTO button to place the entire system in the
automatic mode. After a five
-second display of the
current settings, only the word AUTO and the outside
temperature will be shown on the digital display. The
system will operate to achieve your comfort set
temperature as quickly as possible. If you have set the
driver temperature at 60
F (16
C) or 90
F (32
C),
the system will not operate automatically until a
different temperature is selected. The AUTO control
system works best with the windows up and the
removable roof installed or the convertible top up.
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.

3-8
A/C: 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
D (2
C to 4
C).
The light on the A/C button will flash if pressed when
air conditioning is not allowed. 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. FRESH AIR: Press this button to provide fresh
air from the outside. 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 FRESH
AIR instead of recirculate, as required, to control the
temperature in the vehicle. By pressing FRESH AIR, the
system will lock into the fresh air mode. Any adjustment
to the air intake must then be made manually. FRESH
AIR should be used when trying to defrost or defog
windows to help reduce moisture inside the vehicle.
RECIRCULATE: Press this button to limit the
amount of fresh air entering the vehicle. The light on
this air intake button will come on to show when it is
operating. Recirculate is helpful when you are trying to
cool the air quickly or trying to limit odors and dust
from entering the vehicle. When in the AUTO mode,
the system automatically selects recirculate to cool the
vehicle's temperature. By pressing this button, the
system will lock into the recirculated air mode.
Any adjustment to the air intake must then be made
manually. The recirculated air mode is not allowed in
the front defrost or defog modes as fresh air helps
reduce moisture inside the vehicle.

3-11 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.
Defogging and Defrosting
To rapidly defrost the windshield, the FRONT defrost
mode (automatic electronic dual climate control system)
or defrost mode (manual control system) should be used
and the fan speed should be adjusted to the highest
speed. With the manual control system, turn the
temperature control knob all the way to the red area.
To keep the windshield clear and provide heated air to
the floor area of the vehicle, use the DEFOG setting.
Your vehicle is equipped with side window defogger
vents located near the side rearview mirrors.
Rear Window Defogger
REAR: This button turns the rear defogger and
the heated outside mirrors on. The light on the button
will come on when operating. The system automatically
shuts off after approximately 15 minutes. If further
defogging is desired, press the button again and it will
operate for about seven and a half more minutes.
The rear window defogger operates only when the
engine is running.

5-8
Towing Your Vehicle
CAUTION:
To help avoid serious personal injury to you
or others:

Never let passengers ride in a vehicle that is
being towed.

Never tow faster than safe or posted speeds.

Never tow with damaged parts not
fully secured.

Never get under your vehicle after it has
been lifted by the tow truck.

Always secure the vehicle on each side with
separate safety chains when towing it.

Use only the correct hooks.
NOTICE:
Use the proper towing equipment to avoid
damage to the bumper, fascia or fog lamp areas
of the vehicle.
With current trends in automotive styles and design, it is
essential that the correct towing equipment is used to
tow a vehicle. Your vehicle can be towed with wheel
-lift
or car
-carrier equipment.
Consult your dealer or a professional towing service if
you need to have your vehicle towed. See ªRoadside
Assistanceº in the Index.
Engine Overheating
You will find an engine coolant temperature gage on
the instrument cluster and a COOLANT OVER TEMP
message on the Driver Information Center (DIC).
Overheated Engine Protection
Operating Mode
Should an overheated engine condition exist 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).

5-9
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 monitor. See ªEngine Oilº in the Index.
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.

5-10
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.
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.

5-11
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.

5-12
When the engine is cold, the coolant level should be at
or above the FULL COLD mark. If it isn't, you may
have a leak 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.
NOTICE:
Engine damage from running your engine
without coolant isn't covered by your warranty.
See ªOverheated Engine Protection Operating
Modeº in the Index.
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.
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.

5-13 How to Add Coolant to the Coolant
Surge Tank
If you haven't found a problem yet, 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.)
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 coolant surge
tank pressure cap
-- even a little -- they can come
out at high speed. Never turn the cap when the
cooling system, including the coolant surge tank
pressure cap, is hot. Wait for the cooling system
and coolant surge tank pressure cap to cool if you
ever have to turn the pressure cap.