2021 CHEVROLET CORVETTE C8 overheating

Chevrolet Corvette Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14622938) - 2021 - CRC - 9/22/20
Instruments and Controls 83
Caution
If the engine is operated with the rpm in
the warning area at the high end of the
tachometer, the vehicle could be
damaged, and the damage would not be
covered by the vehicle warranty. Do not
operate the engine with the rpm in the
warning area.
Fuel Gauge
When the ignition is on, the fuel gauge
indicates about how much fuel is left in
the tank.
When the indicator nears empty, the low
fuel light comes on. There is still a little fuel
left, but the fuel tank should be filled soon.Here are four things that some owners ask
about. None of these show a problem with
the fuel gauge:
.At the service station, the fuel pump
shuts off before the gauge reads full.
.It takes a little more or less fuel to fill up
than the gauge indicated. For example,
the gauge indicated the tank was half
full, but it actually took a little more or
less than half the tank's capacity to fill
the tank.
.The gauge moves a little while turning a
corner or speeding up.
.The gauge takes a few seconds to
stabilize after the ignition is turned on,
and goes back to empty when the
ignition is turned off.
Engine Coolant Temperature
Gauge
This gauge shows the engine coolant
temperature.If the gauge pointer moves into the red
zone, the engine is too hot.
This reading indicates the same thing as the
warning light. It means that the engine
coolant has overheated. If the vehicle has
been operating under normal driving
conditions, pull off the road, stop the
vehicle, and turn off the engine as soon as
possible. See
Engine Overheating 0248 for
more information.
Transmission Temperature Gauge
This gauge will display when the
transmission is experiencing abnormal
temperatures.
As the transmission begins to overheat, the
gauge fills to the right.
The Transmission Temperature Gauge
monitors all aspects of the transmission.
Elevated transmission temperatures may not
be reflected in the Transmission Fluid
Temperature cluster display gauge.

Chevrolet Corvette Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14622938) - 2021 - CRC - 9/22/20
84 Instruments and Controls
Messages will display to indicate the
severity of the overheating. As the gauge
fills up there will be a reduction in vehicle
performance. Once full, the transmission is
overheated and a message to stop safely
will display. Do not drive the vehicle until
the message clears. SeeDual Clutch
Transmission 0197 for more information.
Seat Belt Reminders
Driver Seat Belt Reminder Light
There is a driver seat belt reminder light on
the instrument cluster.
When the vehicle is started, this light
flashes and a chime may come on to remind
the driver to fasten their seat belt.
Then the light stays on solid until the belt is
buckled. This cycle may continue several
times if the driver remains or becomes
unbuckled while the vehicle is moving. If the driver seat belt is buckled, neither the
light nor the chime comes on.
Front Passenger Seat Belt Reminder
Light
The vehicle may have a front passenger seat
belt reminder light near the passenger
airbag status indicator. See
Passenger
Sensing System 057.
When the vehicle is started, this light
flashes and a chime may come on to remind
passengers to fasten their seat belt.
Then the light stays on solid until the belt is
buckled. This cycle continues several times if
the front passenger remains or becomes
unbuckled while the vehicle is moving.
If the front passenger seat belt is buckled,
neither the chime nor the light comes on.
The front passenger seat belt reminder light
and chime may come on if an object is put
on the seat such as a briefcase, handbag,
grocery bag, laptop, or other electronic device. To turn off the reminder light and/or
chime, remove the object from the seat or
buckle the seat belt.
Airbag Readiness Light
This light shows if there is an electrical
problem with the airbag system. The system
check includes the airbag sensor(s), the
passenger sensing system, the pretensioners,
the airbag modules, the wiring, and the
crash sensing and diagnostic module. For
more information on the airbag system, see
Airbag System
052.
The airbag readiness light comes on for
several seconds when the vehicle is started.
If the light does not come on then, have it
fixed immediately.

Chevrolet Corvette Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14622938) - 2021 - CRC - 9/22/20
Driving and Operating 181
prevent the brake master cylinder from
pressurizing the hydraulic system during its
automated self diagnostic tests that can
possibly occur when a door is opened or the
remote key is present.
{Caution
To avoid personal injury and/or vehicle
damage, always disconnect the battery
before performing service work on the
hydraulic brake system. Bleeding the
brake system with the battery connected
can lead to excessive pressurization of
the system during automatic diagnostic
tests or diagnosis of a leak or air in the
braking system. A Diagnostic Trouble
Code (DTC) may set and vehicle speed
may be limited.
Brake Fluid
Replace existing brake fluid with a qualified
high performance DOT 4 brake fluid from a
sealed container. Brake fluid with a dry
boiling point >310 °C (590 °F) is qualified.
If high performance brake fluid is used,
replace it with GM approved brake fluid
before driving on public roads. If high
performance brake fluid is in the vehicle and
the age of the brake fluid is over a month old or unknown, replace the brake fluid
before track events and competitive driving.
Do not use silicone or DOT-5 brake fluids.
Check the fluid level before each competitive
driving event.
Brake System Flushing & Bleeding
The J55 brake system requires specific
processes for bleeding and fluid flushing.
These can be found in the service manual.
Properly bleeding the brake system is
required for proper operation of the
hydraulic brake system.
Brake Leak Detection
The hydraulic braking system has advanced
diagnostic capability to help detect hydraulic
leaks, trapped air, and other performance
issues. These diagnostics are active when
the hydraulic system is powered. In order to
avoid inadvertently setting a leak Diagnostic
Trouble Code (DTC), disconnect the battery
before servicing the brake system.
If the vehicle sets a DTC related to a brake
system leak, the Brake System Warning
Light will come on and vehicle speed may
be limited to 100 kph (62 mph). Any time a
leak DTC is set, the vehicle should be
inspected carefully for evidence of a leak
and should be repaired immediately. See
your dealer.
Brake Fade Warning Assist
The Brake Fade Warning Assist system
monitors the performance of the brake
system. If the system detects brake fade,
or if the brake fluid is near the boiling point,
the driver will be alerted.
The Brake Fade Warning Assist system is
designed for use with the factory-installed
brake pads or GM-approved replacement
pads. If the brake pads on the vehicle need
to be replaced, use GM-approved brake pads.
If this is not done, the brake fade warning
system may not function properly.
Stage 1 :
The Driver Information Center (DIC)
displays a “Reduce Braking to Avoid
Overheating” message and brake pedal
effort and travel is increased. When the
message displays, the driver should decrease
brake pedal pressure.
Stage 2 : The Driver Information Center
(DIC) displays a “Brakes Overheated Service
Now” message that the brake fluid
temperature is excessive and is about to
boil. The system increases brake pedal effort
and travel, and will also limit vehicle speed.

Chevrolet Corvette Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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186 Driving and Operating
road is wet enough and you are going fast
enough. When the vehicle is hydroplaning, it
has little or no contact with the road.
There is no hard and fast rule about
hydroplaning. The best advice is to slow
down when the road is wet.
Other Rainy Weather Tips
Besides slowing down, other wet weather
driving tips include:
.Allow extra following distance.
.Pass with caution.
.Keep windshield wiping equipment in
good shape.
.Keep the windshield washer fluid reservoir
filled.
.Have good tires with proper tread depth.
SeeTires 0261.
.Turn off cruise control.
Hill and Mountain Roads
Driving on steep hills or through mountains
is different than driving on flat or rolling
terrain. Tips include:
.When driving downhill in D (Drive), the
vehicle may automatically downshift to
assist with speed control.
.A lower gear may also be selected to
provide further speed control.
{Warning
Using the brakes to slow the vehicle on a
long downhill slope can cause brake
overheating, can reduce brake
performance, and could result in a loss of
braking. Shift the transmission to a lower
gear to let the engine assist the brakes
on a steep downhill slope.
{Warning
Coasting downhill in N (Neutral) or with
the ignition off is dangerous. This can
cause overheating of the brakes and loss
of steering assist. Always have the engine
running and the vehicle in gear.
.Drive at speeds that keep the vehicle in
its own lane. Do not swing wide or cross
the center line.
.Be alert on top of hills; something could
be in your lane (e.g., stalled car, crash).
.Pay attention to special road signs (e.g.,
falling rocks area, winding roads, long
grades, passing or no-passing zones) and
take appropriate action.
Winter Driving
Driving on Snow or Ice
Snow or ice between the tires and the road
creates less traction or grip, so drive
carefully. Wet ice can occur at about 0 °C
(32 °F) when freezing rain begins to fall.
Avoid driving on wet ice or in freezing rain
until roads can be treated.
For Slippery Road Driving:
.Accelerate gently. Accelerating too quickly
causes the wheels to spin and makes the
surface under the tires slick.
.Turn on Traction Control. See Traction
Control/Electronic Stability Control 0205.
.The Antilock Brake System (ABS) improves
vehicle stability during hard stops, but
the brakes should be applied sooner than
when on dry pavement. See Antilock
Brake System (ABS) 0203.
.Allow greater following distance and
watch for slippery spots. Icy patches can
occur on otherwise clear roads in shaded
areas. The surface of a curve or an
overpass can remain icy when the
surrounding roads are clear. Avoid sudden
steering maneuvers and braking while
on ice.

Chevrolet Corvette Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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230 Vehicle Care
Vehicle Care
General Information
General Information . . . . . . . . . . . . . . . . . . . 231
California Proposition 65 Warning . . . . . 231
California Perchlorate MaterialsRequirements . . . . . . . . . . . . . . . . . . . . . . . . 231
Accessories and Modifications . . . . . . . . . 231
Lifting the Vehicle . . . . . . . . . . . . . . . . . . . . . 232
Vehicle Checks
Doing Your Own Service Work . . . . . . . . . 233
Underhood Compartment Overview . . . 234
Engine Compartment Overview . . . . . . . . 235
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238
Engine Oil Life System . . . . . . . . . . . . . . . . . 241
Dual Clutch Transmission Fluid . . . . . . . . 241
Dual Clutch Transmission Fluid Life System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
Engine Air Filter Life System . . . . . . . . . . 242
Engine Air Cleaner/Filter . . . . . . . . . . . . . . . 243
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . 245
Engine Overheating . . . . . . . . . . . . . . . . . . . 248
Washer Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 249
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250
Battery - North America . . . . . . . . . . . . . . . 251 Park Brake and P (Park) Mechanism
Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252
Wiper Blade Replacement . . . . . . . . . . . . . 252
Windshield Replacement . . . . . . . . . . . . . . . 253
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . . . . . . . 254
Bulb Replacement
LED Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . 254
Electrical System
Electrical System Overload . . . . . . . . . . . . 254
Fuses and Circuit Breakers . . . . . . . . . . . . . 255
Instrument Panel Fuse Block . . . . . . . . . . . 255
Rear Compartment Fuse Block . . . . . . . . . 258
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
All-Season Tires . . . . . . . . . . . . . . . . . . . . . . . . 261
Winter Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
Run-Flat Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 262
Low-Profile Tires . . . . . . . . . . . . . . . . . . . . . . . 263
Summer Tires . . . . . . . . . . . . . . . . . . . . . . . . . 263
Tire Sidewall Labeling . . . . . . . . . . . . . . . . . 263
Tire Designations . . . . . . . . . . . . . . . . . . . . . . 264
Tire Terminology and Definitions . . . . . . 265 Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . 267
Tire Pressure for High-Speed
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 268
Tire Pressure Monitor System . . . . . . . . . 269
Tire Pressure Monitor Operation . . . . . . 270
Tire Inspection . . . . . . . . . . . . . . . . . . . . . . . . . 272
Tire Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . 272
When It Is Time for New Tires . . . . . . . . 273
Buying New Tires . . . . . . . . . . . . . . . . . . . . . 274
Different Size Tires and Wheels . . . . . . . . 275
Uniform Tire Quality Grading . . . . . . . . . . 275
Wheel Alignment and Tire Balance . . . . 277
Wheel Replacement . . . . . . . . . . . . . . . . . . . 277
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
If a Tire Goes Flat . . . . . . . . . . . . . . . . . . . . . 278
Jump Starting
Jump Starting - North America . . . . . . . . 278
Towing the Vehicle
Towing the Vehicle . . . . . . . . . . . . . . . . . . . . 281
Recreational Vehicle Towing . . . . . . . . . . . 283
Appearance Care
Exterior Care . . . . . . . . . . . . . . . . . . . . . . . . . . 283
Interior Care . . . . . . . . . . . . . . . . . . . . . . . . . . 288
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290

Chevrolet Corvette Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14622938) - 2021 - CRC - 9/22/20
Vehicle Care 245
Caution
If the air cleaner/filter is off, dirt can
easily get into the engine, which could
damage it. Always have the air cleaner/
filter in place when driving.
Cooling System
The cooling system allows the engine to
maintain the correct working temperature.
Convertible
1. Engine Cooling Fans (Out of View)
2. Coolant Surge Tank with Pressure Cap
Coupe
1. Engine Cooling Fans (Out of View)
2. Coolant Surge Tank with Pressure Cap
{Warning
An underhood electric fan can start up
even when the engine is not running and
can cause injury. Keep hands, clothing,
and tools away from any underhood
electric fan.
{Warning
Do not touch heater or radiator hoses,
or other engine parts. They can be very
hot and can burn you. Do not run the
engine if there is a leak; all coolant could
leak out. That could cause an engine fire
and can burn you. Fix any leak before
driving the vehicle.
Engine Coolant
The cooling system in the vehicle is filled
with DEX-COOL engine coolant. See
Recommended Fluids and Lubricants0301.
The fluid requires changing at certain
intervals. See Maintenance Schedule 0293.
The following explains the cooling system
and how to check and add coolant when it
is low. If there is a problem with engine
overheating, see Engine Overheating 0248.
What to Use
{Warning
Plain water, or other liquids such as
alcohol, can boil before the proper
coolant mixture will. With plain water or
(Continued)

Chevrolet Corvette Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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246 Vehicle Care
Warning (Continued)
the wrong mixture, the engine could get
too hot but there would not be an
overheat warning. The engine could catch
fire and you or others could be burned.
Use a mixture of 40% DEX-COOL coolant and
60% clean, drinkable water. If using this
mixture, nothing else needs to be added.
This mixture:
.Gives freezing protection down to −28 °C
(−18 °F), outside temperature.
.Gives boiling protection up to 129 °C
(265 °F), engine temperature.
.Protects against rust and corrosion.
.Will not damage aluminum parts.
.Helps keep the proper engine
temperature.
Caution
Do not use anything other than a mix of
DEX-COOL coolant that meets GM
Standard GMW3420 and clean, drinkable
water. Anything else can cause damage
to the engine cooling system and the
vehicle, which would not be covered by
the vehicle warranty. Never dispose of engine coolant by putting
it in the trash, pouring it on the ground,
or into sewers, streams, or bodies of water.
Have the coolant changed by an authorized
service center, familiar with legal
requirements regarding used coolant
disposal. This will help protect the
environment and your health.
If ambient temperatures are anticipated
below
−28 °C (−18 °F), make sure a proper
mixture ratio of 50% DEX-COOL coolant and
50% clean, drinkable water is used.
Checking Coolant
Be sure the cooling system is cool and that
the vehicle is on a level surface.
Check to see if coolant is visible in the
coolant surge tank. If the coolant inside the
coolant surge tank is boiling, do not do
anything else until it cools down. If coolant
is visible but the coolant level is not at or
above the cold fill line, add a mixture of
40% DEX-COOL coolant and 60% clean,
drinkable water at the coolant recovery
tank, but be sure the cooling system is cool
before this is done. See Engine Overheating
0 248. The surge tank is in the engine
compartment. See
Engine Compartment
Overview 0235.
When the engine is cold, the coolant level
should be at the COLD FILL indicator in the
coolant surge tank.
When the engine is hot, the level could be
higher than the COLD FILL indicator. If the
coolant is below the COLD FILL indicator
when the engine is hot, there could be a
leak in the cooling system.
If the coolant is low, add the coolant or take
the vehicle to your dealer for service.

Chevrolet Corvette Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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248 Vehicle Care
7. Verify coolant level after the engine isshut off and the coolant is cold.
If necessary, repeat coolant fill procedure
Steps 3−7.
If the coolant still is not at the proper
level when the system cools down again,
see your dealer.
Caution
If the pressure cap is not tightly installed,
coolant loss and engine damage may
occur. Be sure the cap is properly and
tightly secured.
Engine Overheating
The vehicle has several indicators to warn of
engine overheating.
There is an engine coolant temperature
gauge on the instrument cluster. See Engine
Coolant Temperature Gauge 083. The
vehicle may also display a message on the
Driver Information Center (DIC).
If the decision is made not to lift the hatch
but to get service help right away, see
Roadside Assistance Program 0311.
If the decision is made to lift the hatch,
make sure the vehicle is parked on a level
surface. Then check to see if the engine cooling fans
are running. There are two cooling fans
located in the front (one at each corner) and
two cooling fans in the rear (one on each
side of the engine). If the engine is
overheating, the fans should be running.
If they are not, do not continue to run the
engine, and have the vehicle serviced.
Caution
Do not run the engine if there is a leak
in the engine cooling system. This can
cause a loss of all coolant and can
damage the system and vehicle. Have
any leaks fixed right away.
If Steam Is Coming from the Engine
{Warning
Steam and scalding liquids from a hot
cooling system are under pressure.
Turning the pressure cap, even a little,
can cause them to come out at high
speed and you could be burned. Never
turn the cap when the cooling system,
including the pressure cap, is hot. Wait
for the cooling system and pressure cap
to cool.
If Steam Is Coming from the Engine
Compartment with no Overheat Warning
Water from rain and car washes could enter
the engine compartment and contact hot
surfaces. If steam is coming from the engine
compartment with no accompanying
overheat warning, no service is needed.
If No Steam Is Coming from the Engine
If an engine overheat warning is displayed
but no steam can be seen or heard, the
problem may not be too serious. Sometimes
the engine can get a little too hot when the
vehicle:
.Climbs a long hill on a hot day.
.Stops after high-speed driving.
.Idles for long periods in traffic.
If the overheat warning is displayed with no
sign of steam: 1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the highest fan
speed. Open the windows as necessary.
3. When it is safe to do so, pull off the road, shift to P (Park) or N (Neutral), and
let the engine idle.