2018 CHEVROLET TAHOE overheating

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349385) - 2018 - crc - 11/3/17
210 Driving and Operating
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, accident).
. 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 0242.
. 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) 0239.

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349385) - 2018 - crc - 11/3/17
Driving and Operating 223
at or below−18 °C (0 °F). Vehicles
with an engine heater should be
plugged in at least four hours before
starting. There may be an internal
thermostat in the plug end of the
cord, which will prevent engine
heater operation at temperatures
above −18 °C (0 °F).
To Use the Engine Heater
1. Turn off the engine.
2. Open the hood and unwrap the
electrical cord. The cord is by
the left front fender, next to the
engine compartment fuse
block.
Check the heater cord for
damage. If it is damaged, do
not use it. See your dealer for
a replacement. Inspect the
cord for damage yearly.
3. Plug the cord into a normal, grounded 110-volt AC outlet.
{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 or
extension cord, could make
(Continued)
Warning (Continued)
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. Never
close the hood on the
heater cord.
. Before starting the vehicle,
unplug the cord, reattach
the cover to the plug, and
securely fasten the cord.
Keep the cord away from
any moving parts.
4. Before starting the engine, be sure to unplug and store the
cord as it was before to keep it

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349385) - 2018 - crc - 11/3/17
Driving and Operating 273
If the trailer turn signal bulbs burn
out, the arrows on the instrument
cluster will still flash for turns. It is
important to check occasionally to
be sure the trailer bulbs are still
working.
Driving on Grades
Reduce speed and shift to a lower
gearbefore starting down a long or
steep downgrade. If the
transmission is not shifted down, the
brakes might get hot and no longer
work well.
Vehicles 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, use the Tow/Haul
Mode to prevent damage to the
engine or transmission. See Tow/
Haul Mode 0233.
When towing at high altitude on
steep uphill grades, consider the
following: Engine coolant will boil at
a lower temperature than at normal
altitudes. If the engine is turned off
immediately after towing at high altitude on steep uphill grades, the
vehicle may show signs similar to
engine overheating. To avoid this,
let the engine run while parked,
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 0309.
Parking on Hills
{Warning
Parking the vehicle on a hill with
the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both
the vehicle and the trailer can be
damaged. When possible, always
park the rig on a flat surface.
If parking the rig 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, release the regular
brakes until the chocks absorb
the load.
4. Reapply the brake pedal. Then apply the parking brake and
shift into P (Park).
5. Release the brake pedal.
Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
2. Start the engine.
3. Shift into a gear.
4. Release the parking brake.
5. Let up on the brake pedal.
6. Drive slowly until the trailer is clear of the chocks.
7. Stop and have someone pick up and store the chocks.

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349385) - 2018 - crc - 11/3/17
Vehicle Care 289
Vehicle Care
General Information
General Information . . . . . . . . . . 290
California Proposition65 Warning . . . . . . . . . . . . . . . . . 291
California Perchlorate Materials Requirements . . . . . 291
Accessories and Modifications . . . . . . . . . . . . . . . . 291
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 292
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 292
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 293
Engine Oil . . . . . . . . . . . . . . . . . . . . 297
Engine Oil Life System . . . . . . . 299
Automatic Transmission Fluid (6-Speed Transmission) . . . . . 301
Automatic Transmission Fluid (10-Speed Transmission) . . . 304
Engine Air Cleaner/Filter . . . . . . 304
Cooling System . . . . . . . . . . . . . . 305
Engine Overheating . . . . . . . . . . 309
Engine Fan . . . . . . . . . . . . . . . . . . . 310
Power Steering Fluid . . . . . . . . . 311
Washer Fluid . . . . . . . . . . . . . . . . . 311 Brakes . . . . . . . . . . . . . . . . . . . . . . . 312
Brake Fluid . . . . . . . . . . . . . . . . . . . 312
Battery - North America . . . . . . 314
Four-Wheel Drive . . . . . . . . . . . . . 314
Front Axle . . . . . . . . . . . . . . . . . . . . 315
Rear Axle . . . . . . . . . . . . . . . . . . . . 315
Starter Switch Check . . . . . . . . . 316
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 317
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . 317
Park Brake and P (Park) Mechanism Check . . . . . . . . . . 317
Wiper Blade Replacement . . . . 318
Glass Replacement . . . . . . . . . . 319
Windshield Replacement . . . . . 319
Gas Strut(s) . . . . . . . . . . . . . . . . . . 319
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 320
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 321
Halogen Bulbs . . . . . . . . . . . . . . . . 321
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . . . . . . . 321
LED Lighting . . . . . . . . . . . . . . . . . 321
Headlamps . . . . . . . . . . . . . . . . . . . 321
Fog Lamps . . . . . . . . . . . . . . . . . . . 322
Front Turn Signal Lamps . . . . . 322 Taillamps, Turn Signal,
Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . . . 322
License Plate Lamp . . . . . . . . . . 324
Electrical System
Electrical System Overload . . . 324
Fuses and Circuit Breakers . . . 325
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 325
Instrument Panel Fuse Block (Left) . . . . . . . . . . . . . . . . . 330
Instrument Panel Fuse Block (Right) . . . . . . . . . . . . . . . . . . . . . . 333
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 335
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 336
All-Season Tires . . . . . . . . . . . . . . 337
Winter Tires . . . . . . . . . . . . . . . . . . 337
Low-Profile Tires . . . . . . . . . . . . . 338
All-Terrain Tires . . . . . . . . . . . . . . . 338
Tire Sidewall Labeling . . . . . . . . 338
Tire Designations . . . . . . . . . . . . . 339
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . 340
Tire Pressure . . . . . . . . . . . . . . . . . 343
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . 344

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349385) - 2018 - crc - 11/3/17
306 Vehicle Care
1. Coolant Surge Tank
2. Coolant Surge TankPressure Cap
3. Engine Electric Cooling Fans
{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 is designed to
remain in the vehicle for 5 years or
240 000 (150,000 mi), whichever
occurs first.
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 0309.
What to Use
{Warning
Plain water, or other liquids such
as alcohol, can boil before the
proper coolant mixture will. With
plain water or 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 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant. This mixture:
. Gives freezing protection down
to−37 °C (−34 °F), outside
temperature
. Gives boiling protection up to
129 °C (265 °F), engine
temperature
. Protects against rust and
corrosion
. Will not damage aluminum parts

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349385) - 2018 - crc - 11/3/17
Vehicle Care 309
By this time, the coolant level
inside the coolant surge tank
may be lower. If the level is
lower, add more of the proper
mixture to the coolant surge
tank until the level reaches the
full cold mark.
5. Replace the pressure cap tightly.
6. Verify coolant level after the engine is shut off and the
coolant is cold. If necessary,
repeat coolant fill procedure
Steps 1–6.
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
For a heavy-duty Suburban, see the
Suburban Heavy-Duty Package
supplement.
Caution
Running the engine without
coolant may cause damage or a
fire. Vehicle damage would not be
covered by the vehicle warranty.
The vehicle has several indicators
to warn of engine overheating.
There is a coolant temperature
gauge in the vehicle's instrument
cluster. See Engine Coolant
Temperature Gauge 0149.
In addition, there are ENGINE
OVERHEATED STOP ENGINE,
ENGINE OVERHEATED IDLE
ENGINE, and ENGINE POWER IS
REDUCED messages in the Driver
Information Center (DIC).
If the decision is made not to lift the
hood when this warning appears,
get service help right away.
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface. Check to see if the engine cooling
fan(s) are running. If the engine is
overheating, the fans should be
running. If they are not, do not
continue to run the engine. 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 Compartment
{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
(Continued)

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349385) - 2018 - crc - 11/3/17
336 Vehicle Care
RelaysUsage
1 Rear window defogger
16 Liftgate
17 Liftglass
18 Rear fog lamp
20 Heated mirrorWheels and Tires
Tires
Every new GM vehicle has
high-quality tires made by a
leading tire manufacturer. See
the warranty manual for
information regarding the tire
warranty and where to get
service. For additional
information refer to the tire
manufacturer.
{Warning
.Poorly maintained and
improperly used tires are
dangerous.
.Overloading the tires can
cause overheating as a
result of too much
flexing. There could be a
blowout and a serious
crash. See Vehicle Load
Limits 0212.
(Continued)
Warning (Continued)
.Underinflated tires pose
the same danger as
overloaded tires. The
resulting crash could
cause serious injury.
Check all tires frequently
to maintain the
recommended pressure.
Tire pressure should be
checked when the tires
are cold.
.Overinflated tires are
more likely to be cut,
punctured, or broken by
a sudden impact —such
as when hitting a pothole.
Keep tires at the
recommended pressure.
.Worn or old tires can
cause a crash. If the
tread is badly worn,
replace them.
(Continued)

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349385) - 2018 - crc - 11/3/17
Vehicle Care 343
Vehicle Maximum Load on the
Tire
:Load on an individual tire
due to curb weight, accessory
weight, occupant weight, and
cargo weight.
Vehicle Placard
:A label
permanently attached to a
vehicle showing the vehicle
capacity weight and the original
equipment tire size and
recommended inflation pressure.
See “Tire and Loading
Information Label” underVehicle
Load Limits 0212.
Tire Pressure
Tires need the correct amount of
air pressure to operate
effectively. Caution
Neither tire underinflation nor
overinflation is good.
Underinflated tires, or tires
that do not have enough air,
can result in:
.Tire overloading and
overheating which could
lead to a blowout.
.Premature or
irregular wear.
.Poor handling.
.Reduced fuel economy.
Overinflated tires, or tires that
have too much air, can
result in:
.Unusual wear.
.Poor handling.
.Rough ride.
.Needless damage from
road hazards. The Tire and Loading
Information label on the vehicle
indicates the original equipment
tires and the correct cold tire
inflation pressures. The
recommended pressure is the
minimum air pressure needed to
support the vehicle's maximum
load carrying capacity.
For additional information
regarding how much weight the
vehicle can carry, and an
example of the Tire and Loading
Information label, see
Vehicle
Load Limits 0212. How the
vehicle is loaded affects vehicle
handling and ride comfort. Never
load the vehicle with more
weight than it was designed to
carry.
When to Check
Check the tires once a month
or more.