2018 LEXUS RCF engine coolant

4517-2. Steps to take in an emergency
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U) 7
When trouble arises ●
Fluid leaks under the vehicle.
(Water dripping from the air co nditioning after use is normal.)●
Flat-looking tires or uneven tire wear ●
Engine coolant temperature gauge cont inually points higher than normal.●
Changes in exhaust sound ●
Excessive tire squeal when cornering ●
Strange noises related to the suspension system ●
Pinging or other noises related to the engine ●
Engine missing, stumbling or running roughly ●
Appreciable loss of power ●
Vehicle pulls heavily to one side when braking ●
Vehicle pulls heavily to one side when driving on a level road ●
Loss of brake effectiveness, spongy f eeling, pedal almost touches the floorIf you think something is wrong If you notice any of the following symptoms, your vehicle probably needs
adjustment or repair. Contact your Lexus dealer as soon as possible.
Visible symptoms
Audible symptoms
Operational symptoms

4677-2. Steps to take in an emergency
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U) 7
When trouble arises Indicates a malfunction in:
• The SRS airbag system;
• The front passenger occupant classification system; or
• The seat belt pretensioner system
A buzzer also sounds.
 Have the vehicle inspected by your Lexus dealer.
Indicates a malfunction in:
• The ABS; or
• The brake assist system
A buzzer also sounds.
 Have the vehicle inspected by your Lexus dealer.
Indicates that the engine coolant temperature is too high
A buzzer also sounds.
 P. 526Warning message Details/Actions(U.S.A.) (Canada)

526 7-2. Steps to take in an emergency
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)●
The engine coolant temperature gauge (  P. 91, 96) is in 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.
Stop the vehicle in a safe place and tu rn off the air conditioning system, and
then stop the engine.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.If your vehicle overheats The following may indicate that your vehicle is overheating.
Correction procedures 1
2

5277-2. Steps to take in an emergency
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U) 7
When trouble arises After the engine has cooled down suff iciently, inspect th e hoses and radiator
core (radiator) for any leaks.
Radiator
Cooling fans If a large amount of coolant leaks, immediately contact your Lexus dealer. 3
1
2
RC350/RC300 AWD 
RC300
RC F

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.