engine coolant LEXUS RCF 2018 Owner's Manual

528 7-2. Steps to take in an emergency
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)The coolant level is satisfactory if it is between the full (“FULL” or “F”) and low
(“LOW” or “L”) lines on the reservoir.
Reservoir cap
“FULL” or “F”
“LOW” or “L” 4
1
2
3
Engine (RC350/RC300 AWD) 
Engine (RC300)
Engine (RC F) 
Intercooler (RC300)

5297-2. Steps to take in an emergency
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U) 7
When trouble arises Add coolant if necessary. Water can be used in an emerge ncy if coolant is unavailable.
Start the engine and turn the air conditio ning system on to check that the radi-
ator cooling fans operate 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 operating by checking the fan sound and air flow.
If it is difficult to check these, turn the air conditioning system on and off repeatedly.
(The fan may not operate in freezing temperatures.)
If the fans are not operating:
Stop the engine immediately an d contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the nearest Lexus dealer. 5 
Engine (RC350/RC300 AWD) 
Engine (RC300)
Engine (RC F) 
Intercooler (RC300)
6
7

530 7-2. Steps to take in an emergency
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)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 h ood, do not open the hood until the steam
has subsided. The engine compartment 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 seri-
ous injury. ●
RC350/RC300 AWD: While the engine
and radiator are hot, do not loosen or remove
the coolant reservoir 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 radiators are
hot, do not loosen or remove the coolant res-
ervoir cap, coolant inlet cap, or intercooler
coolant reservoir cap.
High temperature steam or coolant could
spray out.
●
RC F: While the engine and radiator are hot,
do not loosen or remove the coolant reser-
voir cap.
High temperature steam or coolant could
spray out.

5317-2. Steps to take in an emergency
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U) 7
When trouble arises NOTICE ■
When adding engine coolant
Add coolant slowly after the engine has cool ed down sufficiently. Adding cool coolant
to a hot engine too quickly can cause damage to the engine. ■
To prevent damage to the cooling system
Observe the following precautions: ●
Avoid contaminating the coolant with foreig n matter (such as sand or dust etc.).●
Do not use any coolant additive.

544 8-1. Specifications
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)* : The fluid capacity is a reference quantity.
If replacement is necessary, contact your Lexus dealer.
■
Spark plugCooling system Capacity
* RC350/
RC300
AWD 10.0 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.)
RC F 12.2 qt. (11.5 L, 10.1 Imp. qt.)
Coolant type Use either of the following:
• “Toyota Super Long Life Coolant”
• Similar high-quality ethylene glycol-based non-sili-
cate, non-amine, non-nitrite, and non-borate coolant
with long-life hybrid organic acid technology
Do not use plain water alone.
Ignition system RC350/RC300
AWD RC300 RC F
Make DENSO
FK20HBR8 NGK
DILFR7K9G DENSO
FK20HBR-J8
Gap 0.031 in. (0.8 mm) 0.035 in. (0.9 mm) 0.031 in. (0.8 mm)
NOTICE ■
Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust the spark plug gap.

564 8-1. Specifications
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)Glossary of tire terminology Tire related term Meaning
Cold tire inflation pressure Tire pressure when the vehicle has been parked for
three hours or more, or has no t been driven more than 1
mile or 1.5 km un der that condition
Maximum inflation pres-
sure The maximum cold inflated pr essure to which a tire may
be inflated, shown on the sidewall of the tire
Recommended inflation
pressure Cold tire inflation pressure recommended by a manu-
facturer
Accessory weight The combined weight (in exce ss of those standard items
which may be replaced) of automatic transmission,
power steering, power brakes, power windows, power
seats, radio and heater, to the extent that these items are
available as factory-installed equipment (whether
installed or not)
Curb weight The weight of a motor vehicle with standard equipment,
including the maximum capacity of fuel, oil and coolant,
and if so equipped, air co nditioning and additional
weight optional engine
Maximum loaded vehicle
weight The sum of:
(a) Curb weight
(b) Accessory weight
(c) Vehicle capacity weight
(d) Production options weight
Normal occupant weight 150 lb. (68 kg) times the numb er of occupants specified
in the second column of Table 1
* that follows
Occupant distribution Distribution of occupants in a vehicle as specified in the
third column of Table 1
* below
Production options weight The combined weight of in stalled regular production
options weighing over 5 lb. (2.3 kg) in excess of the
standard items which they re place, not previously con-
sidered in curb weight or accessory weight, including
heavy duty brakes, ride leve lers, roof rack, heavy duty
battery, and special trim
Rim A metal support for a tire or a tire and tube assembly
upon which the tire beads are seated

621Alphabetical index
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)Emergency, in case of
If a warning buzzer sounds...........453
If a warning light turns on...............453
If a warning message
is displayed ....................................... 460
If the electronic key
does not operate properly ......... 518
If the engine will not start................. 516
If the vehicle battery is
discharged ......................................... 522
If you have a flat tire .............489, 502
If you think something
is wrong................................................ 451
If your vehicle becomes stuck .....532
If your vehicle has to be
stopped in an emergency ..........443
If your vehicle needs
to be towed ....................................... 444
If your vehicle overheats ................526
Engine ....................................................... 539
ACCESSORY mode..................... 208
Compartment......................................397
Engine switch .......................................207
Hood ........................................................393
How to start the engine ..................207
Identification number ...................... 538
If the engine will not start................. 516
Ignition switch (engine switch)....207
Overheating .........................................526 Engine coolant ...................................... 404
Capacity................................................. 544
Checking ............................................... 404
Preparing and checking
before winter ........................320, 320
Engine coolant temperature
gauge ..................................................91, 96
Engine immobilizer system .................. 79
Engine oil ................................................. 400
Capacity.................................................540
Checking .............................................. 400
Preparing and checking
before winter ........................320, 320
Engine oil maintenance data ........... 403
Engine oil temperature gauge............96
Engine switch ..........................................207
Enhanced VSC ....................................... 312
EPS (Electric Power Steering) ......... 313
Warning light ....................................... 454
Event data recorder (EDR)................... 10
Expert mode ............................................ 316

623Alphabetical index
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)Garage door opener .......................... 359
Gauges ................................................. 91, 96
Glove box ................................................. 351
Glove box light ....................................... 351
Head restraints ......................................... 171
Headlight cleaner................................. 233
Headlights ............................................... 225
Automatic High Beam
system ..................................................228
Light switch ........................................... 225
Replacing light bulbs ........................439
Heaters
Air conditioning system ..................333
Heated steering wheel ....................344
Outside rear view mirrors ............ 338
Seat heaters ..........................................345
Hill-start assist control ..........................312
Hood .......................................................... 393
Open ........................................................393
Hooks
Cargo hooks ....................................... 353
Coat hooks .......................................... 358
Retaining hooks (floor mat) .............30
Horn ............................................................. 175 I/M test ..................................................... 390
Identification
Engine .....................................................538
Vehicle .................................................... 537
Ignition switch (engine switch) ........207
Illuminated entry system ................... 348
Immobilizer system ................................. 79
Indicators .....................................................87
Initialization
Maintenance ........................... 385, 403
Meter .................................................. 111, 129
Moon roof ...............................................187
Multi-information display.......... 111, 129
Power windows................................... 183
Tire pressure
warning system ................................. 413
Initiators (tire pressure
warning system) .................................. 418
Inside rear view mirror......................... 176
Instrument panel light
control ............................................ 94, 100
Intercooler .............................................. 406
Intercooler coolant.............................. 404
Capacity................................................. 544
Checking ...............................................405
Preparing and checking
before winter ........................320, 320
Interior lights .......................................... 348
Intuitive parking assist ........................ 280G
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