cooling LEXUS RC350 2021 User Guide

2626-3. Do-it-yourself maintenance
Check the radiator, condenser and
intercooler radiator and clear away
any foreign objects.
If any of the above parts are 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.
RC350/RC300 AWD
RC300
■Adding fluid
Make sure to check the fluid type and
prepare the necessary item.
 Fluid type
SAE J1703 or FMVSS No.116 DOT 3
brake fluid
SAE J1704 or FMVSS No.116 DOT 4
brake fluid
Item
Clean funnel
WARNING
■When the engine is hot
Do not remove the engine coolant reser-
voir cap, intercooler coolant reservoir
cap and coolant inlet cap. ( P.325)
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, con-
denser and intercooler radiator
(if equipped)
WARNING
■When the engine is hot
Do not touch the radiator, condenser or
intercooler radiator as they may be hot
and cause serious injuries, such as burns.
Checking and adding the brake
fluid

3227-2. Steps to take in an emergency
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.
 RC350/RC300 AWD
WARNING
●Do not allow children near the battery.
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.
If your vehicle overheats
The following may indicate that
your vehicle is overheating.
 The engine coolant temperature
gauge ( P.66) is in the red zone
or a loss of engine power is expe-
rienced. (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

3237-2. Steps to take in an emergency
7
When trouble arises
Radiator
Cooling fans
If a large amount of coolant leaks, immedi-
ately contact your Lexus dealer.
RC300
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 (“FULL” or “F”)
and low (“LOW” or “L”) lines on the
reservoir.
 Engine (RC350/RC300 AWD) Reservoir cap
“FULL” or “F”
“LOW” or “L”
 Engine (RC300)
Reservoir cap
“FULL” or “F”
“LOW” or “L”
 Intercooler (RC300)
Reservoir cap
“FULL” or “F”
“LOW” or “L”
A
B
A
B
A
B
C
A
B
C
A
B
C

3247-2. Steps to take in an emergency
5Add coolant if necessary.
Water can be used in an emergency if
coolant is unavailable.
Engine (RC350/RC300 AWD)
 Engine (RC300)
 Intercooler (RC300)
6 Start 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.
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.

3257-2. Steps to take in an emergency
7
When trouble arises
WARNING
●RC350/RC300 AWD: While the
engine and radiator are hot, do not
loosen or remove the coolant reser-
voir cap or coolant inlet cap. (The
coolant inlet cap is located under the
engine cover.)
High temperature steam or coolant
could spray out.
●RC300: While the engine and radia-
tors are hot, do not loosen or remove
the coolant reservoir cap, coolant inlet
cap, or intercooler coolant reservoir
cap.
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.

3328-1. Specifications
*: The fluid capacity is a reference quantity. If replacement is necessary, contact your Lexus dealer.
■Spark plug
Cooling system
Capacity*
RC350/RC3
00 AWD10.0 qt. (9.5 L, 8.4 Imp. qt.)
RC300
Gasoline engine
8.5 qt. (8.0 L, 7.0 Imp. qt.)
Intercooler
3.3 qt. (3.1 L, 2.7 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)
RC350/RC300 AWDRC300
MakeDENSO FK20HBR8NGK DILFR7K9G
Gap0.031 in. (0.8 mm)0.035 in. (0.9 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):
12.3 V or higher
If the voltage is lower than the standard value,
charge the battery.
(Voltage is checked 20 minutes after the engine
and all lights are turned off.)
Charging rates5 A max.

386Alphabetical Index
CareExterior ........................................................... 242
Interior ............................................................. 245
Seat belts........................................................ 245
Wheels and wheel ornaments............ 242
Cargo capacity...............................................125
Cargo hooks ................................................. 229
Center Display ............................................... 212
Chains .............................................................. 206
Child restraint system Child seats definition................................... 40
Child seats installation........................ 44, 47
Front passenger occupant classification system ............................................................. 36
Installing a CRS to the front passenger seat ....................................................................42
Installing CRS with LATCH anchors . 48
Installing CRS with top tether strap.....50
Riding with children ..................................... 40
Types of child restraint system installation method ............................................................. 41
Using an anchor bracket .......................... 49
Child safety Airbag precautions.......................................32
Battery precautions ........................ 264, 321
Child restraint system.......................... 40, 41
Heated steering wheel or seat heater precautions................................................ 223
How your child should wear the seat belt ............................................................................ 25
Installing child restraints ............................ 40
Moon roof precautions ............................. 116
Power window lock switch...................... 113
Seat belt extender precautions ............. 25
Seat belt precautions .................................. 40
Trunk precautions .......................................... 91
Cleaning Exterior ........................................................... 242
Interior ............................................................. 245
Radar sensor................................................. 158
Seat belts........................................................ 245
Wheels and wheel ornaments............ 242 Clock ........................................................66, 230
Clock settings ............................................... 230
Coat hooks..................................................... 230
Compass ......................................................... 237
Condenser ..................................................... 262
Console box .................................................. 228
Consumption screen .....................................79
Cooling system............................................. 260
Engine overheating................................... 322
Cornering lights .............................................143 Replacing light bulbs ................................282
Cruise control Dynamic radar cruise control with full-speed range ........................................176
Cup holders ................................................... 228
Current fuel consumption ...........................73
Curtain shield airbags .................................. 28
Customizable features ................................351
D
Daytime running light system ................... 142
Daytime running lights Replacing light bulbs ................................282
Defogger Outside rear view mirrors.......................219
Rear window ..................................................219
Windshield ......................................................219
Differential Front differential oil............. .......................333
Rear differential oil......... ..................... .......333
Dimension ...................................................... 328
Dinghy towing.................................................126
Display Center Display .............................................. 212
Drive information .......................................... 73
LDA (Lane Departure Alert with steering control) ........................................................... 171
Multi-information display ............................ 71
Warning messages.................................. 305
Distance until next engine oil change .... 70
Do-it-yourself maintenance .................... 249
Door courtesy lights ................................... 225