2015 Lexus IS250 cooling

5068-2. Steps to take in an emergency
IS350/250_U (OM53C50U)
●The needle of the engine coolant temperature gauge (→P. 8 1 ) e n t e r s t h e r e d
zone or a loss of engine power is experienced. (For example, the vehicle
speed does not increase.)
●Steam comes out from under the hood.
Stop the vehicle in a safe place and turn 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.
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,
immediately contact your Lexus
dealer.
If your vehicle overheats
The following may indicate that your vehicle is overheating.
Correction procedures
1
2
3
1
2

5078-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53C50U)
The coolant level is satisfactory if it is
between the “FULL” and “LOW”
lines on the reservoir.Reservoir
“FULL”
“LOW”
Add coolant if necessary.
Water can be used in an emergency if
coolant is unavailable.
Start the engine and turn the air conditioning 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 fans may not operate in freezing temperatures.)
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.
4
1
2
3
5
6
7

5088-2. Steps to take in an emergency
IS350/250_U (OM53C50U)
CAUTION
■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 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.
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 system
Observe the following precautions:
●Avoid contaminating the coolant with foreign matter (such as sand or dust etc.).
●Do not use any coolant additive.
●While the engine and radiator are hot, do not
loosen or remove the coolant reservoir cap
or radiator cap. (The radiator cap is located
under the engine cover.)
High temperature steam or coolant could
spray out.

5169-1. Specifications
IS350/250_U (OM53C50U)
■Spark plug
Cooling system
IS250IS350
Capacity 11.1 qt. (10.5 L, 9.2 Imp. qt.) 9.8 qt. (9.3 L, 8.2 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 organic acid technology
Do not use plain water alone.
Ignition system
Make DENSO FK20HBR11
Gap0.043 in. (1.1 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  12.8 V Fully charged
12.2
 12.4 V Half charged
11.8  12.0 V Discharged
(Check the voltage 20 minutes after the engine and all
lights are turned off.)
Charging rates5 A max.

567Alphabetical index
IS350/250_U (OM53C50U)
Child safety ................................................ 53Airbag precautions .............................. 39
Battery precautions ...............421, 505
Child restraint system ......................... 54
How your child should wear the seat belt .......................................... 32
Installing child restraints.................... 58
Moon roof precautions.................... 144
Power window lock switch ............ 138
Power window precautions .......... 140
Rear door child-protectors ........... 106
Removed electronic key battery precautions.............. 440
Seat belt extender
precautions ...........................................35
Seat belt precautions .......................... 57
Seat heater precautions................. 366
Trunk precautions................................. 112
Child-protectors.................................... 106 Cleaning ....................................... 396, 399
Aluminum wheels .............................. 397
Exterior ...................................................396
Interior ..................................................... 399
Seat belts............................................... 400
Clock .......................................................... 377
Coat hooks ...............................................381
Compass ................................................. 387
Condenser ................................................418
Console box ............................................. 371
Cooling system ....................................... 417 Engine overheating ......................... 506
Cruise control Cruise control ....................................... 192
Dynamic radar crui se control .......196
Cup holders.............................................372
Current fuel consumption ....................87
Curtain shield airbags ............................ 37
Customizable features .......................537