2018 LEXUS RCF cooling

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

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.

619Alphabetical index
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)Cleaning......................................... 376, 381
Aluminum wheels .............................. 377
Exterior....................................................376
Interior ...................................................... 381
Seat belts ............................................... 382
Clock ......................................................... 355
Coat hooks..............................................358
Compass .................................................. 366
Condenser .............................................. 406
Console box ............................................ 351
Cooling system ..................................... 404
Engine overheating...........................526
Cruise control
Dynamic radar cruise control..... 268
Cup holders ............................................ 352
Current fuel consumption ....... 108, 122
Curtain shield airbags ........................... 40
Customizable features ....................... 569 Daytime running light system...........226
Defogger
Outside rear view mirrors ............338
Rear window........................................338
Windshield............................................338
Differential
Front differential .................................545
Rear differential................................... 546
Dimension ............................................... 536
Dinghy towing ....................................... 206
Display
Drive information...................... 108, 122
Dynamic radar cruise control .....268
LDA (Lane Departure Alert
with steering control) ................... 265
Multi-information display....... 103, 118
Warning message.............................460
Distance ...........................................108, 122
Do-it-yourself maintenance............... 391
Door courtesy lights
Location ................................................. 347
Door lock
Doors.........................................................145
Smart access system with
push-button start ..............................156
Wireless remote control..................140 D