2021 CHEVROLET BLAZER overheating

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
Instruments and Controls 97
English Base and Midlevel
Metric Uplevel
English Uplevel
This gauge shows the engine coolant
temperature.
If the pointer moves toward the warning
area at the high end of the gauge, the
engine is too hot.
If the engine coolant has overheated and
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 0271.
Voltmeter Gauge
When the ignition is on, this gauge indicates
the battery voltage.
When the engine is running, this gauge
shows the condition of the charging system.
The gauge can transition from a higher to
lower or a lower to higher reading. This is
normal. If the vehicle is operating outside
the normal operating range, the charging
system light comes on. See Charging System
Light 0100.
Readings outside the normal operating
range can also occur when a large number
of electrical accessories are operating in the
vehicle and the engine is left idling for an
extended period. This condition is normal

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
Instruments and Controls 105
SeeTraction Control/Electronic Stability
Control 0213.
Engine Coolant Temperature
Warning Light
This light comes on briefly while starting
the vehicle.
If it does not, have the vehicle serviced by
your dealer. If the system is working
normally the indicator light goes off.
Caution
The engine coolant temperature warning
light indicates that the vehicle has
overheated. Driving with this light on can
damage the engine and it may not be
covered by the vehicle warranty. See
Engine Overheating 0271.
The engine coolant temperature warning
light comes on when the engine has
overheated. If this happens, pull over and turn off the
engine as soon as possible. See
Engine
Overheating 0271.
Tire Pressure Light
For vehicles with the Tire Pressure Monitor
System (TPMS), this light comes on briefly
when the engine is started. It provides
information about tire pressures and
the TPMS.
When the Light Is On Steady
This indicates that one or more of the tires
are significantly underinflated.
A Driver Information Center (DIC) tire
pressure message may also display. Stop as
soon as possible, and inflate the tires to the
pressure value shown on the Tire and
Loading Information label. See Tire Pressure
0 294. When the Light Flashes First and Then Is On
Steady
If the light flashes for about a minute and
then stays on, there may be a problem with
the TPMS. If the problem is not corrected,
the light will come on at every ignition
cycle. See
Tire Pressure Monitor Operation
0 297.
Engine Oil Pressure Light
Oil pressure can vary with engine speed,
outside temperature, and oil viscosity.
On some models, the oil pump will vary
engine oil pressure according to engine
needs. Oil pressure may change quickly as
the engine speed or load varies. This is
normal. If the oil pressure warning light or
Driver Information Center (DIC) message
indicates oil pressure outside the normal
operating range, check the vehicle's oil as
soon as possible.
Caution
Lack of proper engine oil maintenance
can damage the engine. Driving with the
engine oil low can also damage the
engine. The repairs would not be covered
(Continued)

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
Driving and Operating 195
Warning (Continued)
ignore police warnings and be very
cautious about trying to drive through
flowing water.
Hydroplaning
Hydroplaning is dangerous. Water can build
up under the vehicle's tires so they actually
ride on the water. This can happen if the
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 0287.
.Turn off cruise control.
.Activate All-Wheel Drive (AWD) mode. See
Driver Mode Control 0214.
Hill and Mountain Roads
Driving on steep hills or through mountains
is different than driving on flat or rolling
terrain. Tips include:
.Keep the vehicle serviced and in good
shape.
.Check all fluid levels and brakes, tires,
cooling system, and transmission.
.Shift to a lower gear when going down
steep or long hills.
{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.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
204 Driving and Operating
may have an internal thermostat in the cord
which will prevent engine heater operation
at temperatures above 0 °F (−18 °C).
{Warning
Do not plug in the engine block heater
while the vehicle is parked in a garage or
under a carport. Property damage or
personal injury may result. Always park
the vehicle in a clear open area away
from buildings or structures.
To Use the Engine Heater
1. Turn off the engine.
2. Check the heater cord for damage. If it isdamaged, do not use it. See your dealer
for a replacement. Inspect the cord for
damage yearly.
3. Plug the heater cord into the connector in the front bumper.
4. Plug the cord into a grounded 110-volt AC outlet that is protected by a ground
fault detection function.
{Warning
Improper use of the heater cord or an
extension cord can damage the cord and
may result in overheating and fire.
.Plug the cord into a three-prong
electrical utility receptacle that is
protected by a ground fault detection
function. An ungrounded outlet could
cause an electric shock.
.Use a weatherproof, heavy-duty,
15 amp-rated extension cord if needed.
Failure to use the recommended
extension cord in good operating
condition, or using a damaged heater
(Continued)
Warning (Continued)
or extension cord, could make it
overheat and cause a fire, property
damage, electric shock, and injury.
.Do not operate the vehicle with the
heater cord permanently attached to
the vehicle. Possible heater cord and
thermostat damage could occur.
.While in use, do not let the heater
cord touch vehicle parts or sharp
edges.
.Before starting the vehicle, unplug the
cord. Keep the cord away from any
moving parts.
5. Before starting the engine, be sure to unplug and store the cord as it was
before to keep it away from moving
engine parts. If you do not, it could be
damaged.
The length of time the heater should remain
plugged in depends on several factors. Ask a
dealer in the area where you will be parking
the vehicle for the best advice on this.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
244 Driving and Operating
alone. It is necessary to go much farther
beyond the passed vehicle before returning
to the lane. Pass on level roadways. Avoid
passing on hills if possible.
Backing Up
Hold the bottom of the steering wheel with
one hand. To move the trailer to the left,
move that hand to the left. To move the
trailer to the right, move that hand to the
right. Always back up slowly and, if possible,
have someone guide you.
Making TurnsCaution
Turn more slowly and make wider arcs
when towing a trailer to prevent damage
to your vehicle. Making very sharp turns
could cause the trailer to contact the
vehicle.
Make wider turns than normal when towing,
so the trailer will not go over soft shoulders,
over curbs, or strike road signs, trees,
or other objects. Always signal turns well in
advance. Do not steer or brake suddenly.
Driving on Grades
Reduce speed and shift to a lower gear
before starting down a long or steep
downhill grade. If the transmission is not
shifted down, the brakes may overheat and
result in reduced braking efficiency.
The vehicle can tow in D (Drive). Shift the
transmission to a lower gear if the
transmission shifts too often under heavy
loads and/or hilly conditions.
When towing at higher altitudes, engine
coolant will boil at a lower temperature
than at lower altitudes. If the engine is
turned off immediately after towing at high
altitude on steep uphill grades, the vehicle
could show signs similar to engine
overheating. To avoid this, let the engine
run, preferably on level ground, with the
transmission in P (Park) for a few minutes
before turning the engine off. If the
overheat warning comes on, see Engine
Overheating 0271.
Parking on Hills
{Warning
To prevent serious injury or death,
always park your vehicle and trailer on a
level surface when possible.
When parking the vehicle and trailer on
a hill: 1. Press the brake pedal, but do not shift into P (Park) yet. Turn the wheels into
the curb if facing downhill or into traffic
if facing uphill.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, gradually release the brake pedal to
allow the chocks to absorb the load of
the trailer.
4. Reapply the brake pedal. Then apply the parking brake and shift into P (Park).
5. Release the brake pedal.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
Driving and Operating 245
Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
.Start the engine.
.Shift into a gear.
.Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Maintenance When Trailer Towing
The vehicle needs service more often when
used to tow trailers. See the Maintenance
Schedule 0332. It is especially important to
check the engine oil, axle lubricant, belts,
cooling system, and brake system before
and during each trip.
Check periodically that all nuts and bolts on
the trailer hitch are tight.
Engine Cooling When Trailer Towing
The cooling system may temporarily
overheat during severe operating conditions.
See Engine Overheating 0271.
Trailer Towing
Caution
Towing a trailer improperly can damage
the vehicle and result in costly repairs
not covered by the vehicle warranty. To
tow a trailer correctly, follow the
directions in this section and see your
dealer for important information about
towing a trailer with the vehicle.
Trailer Weight
{Warning
Never exceed the towing capacity for
your vehicle. Safe trailering requires monitoring the
weight, speed, altitude, road grades, outside
temperature, dimensions of the front of the
trailer, and how frequently the vehicle is
used to tow a trailer.
Trailer Weight Ratings
When towing a trailer, the combined weight
of the vehicle, vehicle contents, trailer, and
trailer contents must be below all of the
maximum weight ratings for the vehicle,
including:
.GCWR: Gross Combined Weight Rating
.GVWR: Gross Vehicle Weight Rating
.Maximum Trailer Weight Rating
.Maximum Trailer Tongue Weight Rating
See “Weight-Distributing Hitch Adjustment”
under Towing Equipment 0248 to
determine if equalizer bars are required to
obtain the maximum trailer weight rating.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
Vehicle Care 253
Vehicle Care
General Information
General Information . . . . . . . . . . . . . . . . . . . 254
California Proposition 65 Warning . . . . . 254
California Perchlorate MaterialsRequirements . . . . . . . . . . . . . . . . . . . . . . . . 254
Accessories and Modifications . . . . . . . . . 254
Vehicle Checks
Doing Your Own Service Work . . . . . . . . . 255
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255
Engine Compartment Overview . . . . . . . . 257
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
Engine Oil Life System . . . . . . . . . . . . . . . . 264
Automatic Transmission Fluid . . . . . . . . . 265
Engine Air Filter Life System . . . . . . . . . . 265
Engine Air Cleaner/Filter . . . . . . . . . . . . . . 265
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . 267
Engine Overheating . . . . . . . . . . . . . . . . . . . . 271
Washer Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 272
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
Battery - North America . . . . . . . . . . . . . . . 274
All-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . . . 275
Automatic Transmission Shift Lock Control Function Check . . . . . . . . . . . . . . 275
Park Brake and P (Park) Mechanism Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
Wiper Blade Replacement . . . . . . . . . . . . . 276 Windshield Replacement . . . . . . . . . . . . . . . 277
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . . . . . . . 278
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . . . . . . 278
High Intensity Discharge (HID)
Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
LED Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
Back-Up Lamps . . . . . . . . . . . . . . . . . . . . . . . . 278
Electrical System
High Voltage Devices and Wiring . . . . . . 279
Electrical System Overload . . . . . . . . . . . . 279
Fuses and Circuit Breakers . . . . . . . . . . . . 280
Engine Compartment Fuse Block . . . . . . 280
Instrument Panel Fuse Block . . . . . . . . . . 284
Rear Compartment Fuse Block . . . . . . . . . 285
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
All-Season Tires . . . . . . . . . . . . . . . . . . . . . . . 288
Winter Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
Summer Tires . . . . . . . . . . . . . . . . . . . . . . . . . 289
Tire Sidewall Labeling . . . . . . . . . . . . . . . . . 289
Tire Designations . . . . . . . . . . . . . . . . . . . . . . 291
Tire Terminology and Definitions . . . . . . 292
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . 294
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 295 Tire Pressure Monitor System . . . . . . . . . 296
Tire Pressure Monitor Operation . . . . . . 297
Tire Inspection . . . . . . . . . . . . . . . . . . . . . . . . 300
Tire Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . 300
When It Is Time for New Tires . . . . . . . . 301
Buying New Tires . . . . . . . . . . . . . . . . . . . . . 302
Different Size Tires and Wheels . . . . . . . 303
Uniform Tire Quality Grading . . . . . . . . . 303
Wheel Alignment and Tire Balance . . . . 305
Wheel Replacement . . . . . . . . . . . . . . . . . . . 305
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305
If a Tire Goes Flat . . . . . . . . . . . . . . . . . . . . . 306
Tire Sealant and Compressor Kit . . . . . . . 307
Storing the Tire Sealant and
Compressor Kit . . . . . . . . . . . . . . . . . . . . . . . 313
Tire Changing . . . . . . . . . . . . . . . . . . . . . . . . . . 313
Compact Spare Tire . . . . . . . . . . . . . . . . . . . . 317
Jump Starting
Jump Starting - North America . . . . . . . . 318
Towing the Vehicle
Towing the Vehicle . . . . . . . . . . . . . . . . . . . . 320
Recreational Vehicle Towing . . . . . . . . . . . 321
Appearance Care
Exterior Care . . . . . . . . . . . . . . . . . . . . . . . . . . 323
Interior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
268 Vehicle Care
2.5L L4 Engine
1. Engine Cooling Fan (Out of View)
2. Engine Coolant Surge Tank andPressure Cap
3.6L V6 Engine
1. Engine Cooling Fan (Out of View)
2. Engine Coolant Surge Tank andPressure 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. This coolant
needs to be checked and replaced at
appropriate intervals. See Maintenance
Schedule 0332.
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 0271.
What to Use
{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
(Continued)