2021 LEXUS RX350 cooling

3596-3. Do-it-yourself maintenance
6
Maintenance and care
Washer fluid tank (P.364)
Engine oil filler cap ( P.360)
Engine oil level dipstick ( P.359)
Engine coolant reservoir ( P.361)
Battery ( P.363)
Brake fluid reservoir ( P.362)
Fuse box ( P.381)
Radiator ( P.362)
Condenser ( P.362)
Electric cooling fans
With the engine at operating tempera-
ture and turned off, check the oil level
on the dipstick.
■Checking the engine oil
1 Park the vehicle on level ground.
After warming up the engine and
turning off the engine, wait more
Engine compartment
Components
A
B
C
D
E
F
G
H
I
J
Checking and adding the engine
oil

3626-3. Do-it-yourself maintenance
water. (Minimum temperature: -31°F
[-35°C])
Canada:
“Toyota Super Long Life Coolant” is a mix-
ture of 55% coolant and 45% deionized
water. (Minimum temperature: -44°F
[-42°C])
For more details about coolant, contact
your Lexus dealer.
■If the coolant level drops within a short
time of replenishing
Visually check the radiator, hoses, engine
coolant reservoir cap, drain cock and water
pump.
If you cannot find a leak, have your Lexus
dealer test the cap and check for leaks in
the cooling system.
Check the radiator and condenser and
clear away any foreign objects. If either of the above parts is extremely
dirty or you are not sure of their condi-
tion, have your vehicle inspected by
your Lexus dealer.
■Checking fluid level
The brake fluid level should be
between the “MAX” and “MIN” lines
on the tank.
■Adding fluid
Make sure to check the fluid type and
prepare the necessary item.
 Fluid type
FMVSS No.116 DOT 3 or SAE J1703
brake fluid
Item
Clean funnel
■Brake fluid can absorb moisture from
the air
Excess moisture in the brake fluid can cause
a dangerous loss of braking efficiency. Use
WARNING
■When the engine is hot
Do not remove the engine coolant reser-
voir cap and radiator cap.
The cooling system may be under pres-
sure and may spray hot coolant if the cap
is removed, causing serious injuries, such
as burns.
NOTICE
■When adding coolant
Coolant is neither plain water nor
straight antifreeze. The correct mixture
of water and antifreeze must be used to
provide proper lubrication, corrosion
protection and cooling. Be sure to read
the antifreeze or coolant label.
■If you spill coolant
Be sure to wash it off with water to pre-
vent it from damagi ng parts or paint.
Checking the radiator and con-
denser
WARNING
■When the engine is hot
Do not touch the radiator or condenser
as they may be hot and cause serious
injuries, such as burns.
Checking and adding the brake
fluid

4367-2. Steps to take in an emergency
WARNING
●Make sure each jumper cable is con-
nected to the correct terminal and that
it is not unintentionally in contact with
any other than the intended terminal.
●Do not allow the other end of the
jumper cable connected to the “+” ter-
minal to come into contact with any
other parts or metal surfaces in the
area, such as brackets or unpainted
metal.
●Do not allow the + and - clamps of the
jumper cables to come into contact
with each other.
●Do not smoke, use matches, cigarette
lighters or allow open flame near the
battery.
■Battery precautions
The battery contains poisonous and cor-
rosive acidic electrolyte, while related
parts contain lead and lead compounds.
Observe the following precautions when
handling the battery:
●When working with the battery, always
wear safety glasses and take care not
to allow any battery fluids (acid) to
come into contact with skin, clothing
or the vehicle body.
●Do not lean over the battery.
●In the event that battery fluid comes
into contact with the skin or eyes,
immediately wash the affected area
with water and seek medical attention.
Place a wet sponge or cloth over the
affected area until medical attention
can be received.
●Always wash your hands after handling
the battery support, terminals, and
other battery-related parts.
●Do not allow children near the battery.
■When replacing the battery
●When the vent plug and indicator are
close to the hold down clamp, the bat-
tery fluid (sulfuric acid) may leak.
●For information regarding battery
replacement, contact your Lexus
dealer.
NOTICE
■When handling jumper cables
When connecting the jumper cables,
ensure that they do not become entan-
gled in the cooling fans or engine drive
belt.

4377-2. Steps to take in an emergency
7
When trouble arises
1Stop the vehicle in a safe place and
turn off the air conditioning system,
and then stop the engine.
2 If you see steam:
Carefully lift the hood after the
steam subsides.
If you do not see steam:
Carefully lift the hood.
3 After the engine has cooled down
sufficiently, inspect the hoses and radiator core (radiator) for any
leaks.
Radiator
Cooling fans
If a large amount of coolant leaks, immedi-
ately contact your Lexus dealer.
4
The coolant level is satisfactory if it
is between the “FULL” and “LOW”
lines on the reservoir.
Reservoir
“FULL” line
“LOW” line
Radiator cap
5 Add coolant if necessary.
Water can be used in an emergency if
If your vehicle overheats
The following may indicate that
your vehicle is overheating.
The needle of the engine coolant
temperature gauge ( P.77)
enters the red zone, or a loss of
engine power is experienced.
(For example, the vehicle speed
does not increase.)
 “Engine Coolant Temp High Stop
in a Safe Place See Owner’s
Manual” is shown on the
multi-information display.
 Steam comes out from under the
hood.
Correction procedures
A
B
A
B
C
D

4387-2. Steps to take in an emergency
coolant is unavailable.
6Start the engine and turn the air
conditioning system on to check
that the radiator cooling fans oper-
ate and to check for coolant leaks
from the radiator or hoses.
The fans operate when the air conditioning
system is turned on immediately after a
cold start. Confirm that the fans are oper-
ating by checking the fan sound and air
flow. If it is difficult to check these, turn the
air conditioning system on and off repeat-
edly.
(The fans may not oper ate in freezing tem-
peratures.)
7 If the fans are not operating:
Stop the engine immediately and
contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the
nearest Lexus dealer.
8 Check if “Engine Coolant Temp
High Stop in a Safe Place See
Owner's Manual” is shown on the
multi-information display.
If the message does not disappear:
Stop the engine and contact your Lexus
dealer.
If the message is not displayed:
Have the vehicle inspected at the nearest Lexus dealer.
WARNING
■When inspecting under the hood of
your vehicle
Observe the following precautions.
Failure to do so may result in serious
injury such as burns.
●If steam is seen coming from under the
hood, do not open the hood until the
steam has subsided. The engine com-
partment may be very hot.
●Keep hands and clothing (especially a
tie, a scarf or a muffler) away from the
fans and belts.
Failure to do so may cause the hands
or clothing to be caught, resulting in
serious injury.
●Do not loosen the radiator cap and the
coolant reservoir cap while the engine
and radiator are hot.
High temperature steam or coolant
could spray out.
NOTICE
■When adding engine coolant
Add coolant slowly after the engine has
cooled down sufficiently. Adding cool
coolant to a hot engine too quickly can
cause damage to the engine.
■To prevent damage to the cooling sys-
tem
Observe the following precautions:
●Avoid contaminating the coolant with
foreign matter (such as sand or dust,
etc.).
●Do not use any coolant additive.

4468-1. Specifications
*: The coolant capacity is a reference quantity.If replacement is necessary, contact your Lexus dealer.
Cooling system
Capacity*
RX350 (Vehicles without towing package)
9.5 qt. (9.0 L, 7.9 Imp. qt.)
RX350 (Vehicles with towing package)
10.5 qt. (9.9 L, 8.7 Imp. qt.)
RX350L
13.1 qt. (12.4 L, 11 Imp. qt.)
Coolant type
Use either of the following:
 “Toyota Super Long Life Coolant”
 Similar high-quality ethylene glycol-based non-silicate,
non-amine, non-nitrite, and non-borate coolant with
long-life hybrid orga nic acid technology
Do not use plain water alone.
Ignition system (spark plug)
MakeDENSO FK20HBR8
Gap0.03 in. (0.8 mm)
NOTICE
■Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust the spark plug gap.
Electrical system (battery)
Open voltage at 68°F (20°C):
12.6 V or higher: Fully charged
12.2  12.4 V: Half charged
12.0 V or lower: Discharged
(Turn the engine switch off and turn on the head-
lights for 20 to 30 seconds.)
Charging rates5 A max.

494Alphabetical Index
Bottle holders..................................................316
BrakeBrake hold...................................................... 186
Fluid ...................................................... 362, 447
Parking brake ............................................... 183
Warning light ...............................................403
Brake assist .....................................................274
Break-in tips.................................................... 155
Brightness control Instrument panel light control ................80
BSM (Blind Spot Monitor)....................... 236
Buzzer Hands off steering wheel warning (LTA)......................................................................... 223
C
Care Exterior ........................................................... 344
Interior ............................................................. 347
Seat belts........................................................ 347
Wheels and wheel ornaments............ 344
Cargo capacity.....................................159, 162
Cargo hooks ................................................... 317
Cargo net hooks ............................................ 317
Center Display .............................................288
Chains ................................................................281
Child restraint system Fixed with a LATCH system .................. 54
Fixed with a seat belt...................................50
Front passenger occupant classification system ............................................................. 39
Points to remember .................................... 45
Riding with children ..................................... 45
Types of child restraint system installation method ........................................................... 46
Using an anchor bracket .......................... 57
Child safety Airbag precautions...................................... 36
Battery precautions ......................364, 436
Child restraint system................................. 46
Heated steering wheel and seat heater precautions................................................306 How your child should wear the seat belt
............................................................................. 27
Moon roof precautions............................ 148
Panoramic moon roof precautions ..... 151
Power back door precautions ............. 103
Power window lock switch .................... 146
Power window precautions .................. 145
Rear door child-protectors ................... 102
Seat belt extender precautions.............. 27
Seat belt precautions .................................. 45
Child-protectors............................................102
Cleaning Exterior............................................................ 344
Interior ............................................................. 347
Radar sensor ................................................203
Seat belts ........................................................ 347
Wheels and wheel ornaments ............344
Clock ..........................................................77, 331
Coat hooks.......................................................331
Coin box............................................................316
Compass ......................................................... 340
Condenser ..................................................... 362
Console box ....................................................314
Consumption screen .................................... 92
Cooling system...............................................361 Engine overheating................................... 437
Cornering lights ............................................ 190 Replacing light bulbs ............................... 385
Cruise control Dynamic radar cruise control with full-speed range ...................................... 227
Cup holders .....................................................315
Current fuel consumption .......................... 82
Curtain shield airbags .................................. 30
Customizable features ................................461
D
Daytime running light system .................. 188
Defogger Outside rear view mirrors..................... 294
Rear window ................................................ 294
Windshield .................................................... 294