2020 Lexus IS350 cooling

4737-3. Do-it-yourself maintenance
7
Maintenance and care
IS350 AWD/IS350/IS300 AWD/IS300_U
IS350 AWD/IS350/IS300 AWD
Engine compartment
Fuse boxes (P. 504)
Battery ( P. 482)
Engine oil level dipstick (P. 475)
Engine coolant reservoir (P. 478)
Engine oil filler cap ( P. 476)Brake fluid reservoir (
P. 481)
Washer fluid tank ( P. 484)
Electric cooling fans
Condenser ( P. 480)
Radiator ( P. 480)1
2
3
4
5
6
7
8
9
10

4747-3. Do-it-yourself maintenance
IS350 AWD/IS350/IS300 AWD/IS300_U
IS300
Fuse boxes ( P. 504)
Battery ( P. 482)
Intercooler
Engine oil level dipstick (P. 475)
Engine oil filler cap ( P. 476)
Engine coolant reservoir (P. 478) Brake fluid reservoir (
P. 481)
Washer fluid tank ( P. 484)
Electric cooling fans
Condenser ( P. 480)
Intercooler radiator ( P. 478)
Radiator ( P. 480)
Intercooler coolant reservoir (P. 478)1
2
3
4
5
6
7
8
9
10
11
12
13

4797-3. Do-it-yourself maintenance
7
Maintenance and care
IS350 AWD/IS350/IS300 AWD/IS300_U
■Coolant selection
Only use “Toyota Super Long Life Coolant” or a similar high quality ethylene glycol
based non-silicate, non-amine, non-nitrite, and non-borate coolant with long-life hybrid
organic acid technology.
U.S.A.:
“Toyota Super Long Life Coolant” is a mixt ure of 50% coolant and 50% deionized water.
(Minimum temperature: -31 F [-35 C])
Canada:
“Toyota Super Long Life Cool ant” is a mixture of 55% coolant and 45% deionized water.
(Minimum temperature: -44 F [-42C])
For more details about engine coolant, contact your Lexus dealer.
■If the coolant level drops within a short time of replenishing
Visually check the radiator, hoses, engine coolant reservoir cap, drain cock and water
pump.
If you cannot find a leak, have your Lexus dealer test the cap and check for leaks in the
cooling system.
WARNING
■When the engine is hot
Do not remove the engine coolant reservoir cap, intercooler coolant reservoir cap
(IS300), or coolant inlet cap. ( P. 582)
The cooling system may be under pressure 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 cool-
ing. Be sure to read the antifreeze or coolant label.
■If you spill coolant
Be sure to wash it off with water to prevent it from damaging parts or paint.

5788-2. Steps to take in an emergency
IS350 AWD/IS350/IS300 AWD/IS300_U
WARNING
■Avoiding battery fires or explosions
Observe the following precautions to prevent accidentally igniting the flammable gas
that may be emitted from the battery:
●Make sure each jumper cable is connected to the correct terminal and that it is not
unintentionally in contact with any other than the intended terminal.
●Do not allow the other end of the jumper cab le connected to the “+” terminal to come
into contact with any other parts or metal surfaces in the area, such as brackets or
unpainted metal.
●Do not allow the + and - clamps of the jumper cables to come in to contact with each
other.
●Do not smoke, use matches, cigarette lighters or allow open flame near the battery.
■Battery precautions
The battery contains poisonous and corrosive acidic electrolyte, while related parts
contain lead and lead compounds. Observ e the following precautions when handling
the battery:
●When working with the battery, always wear safety glasses and take care not to allow
any battery fluids (acid) to come into cont act with skin, clothing or the vehicle body.
●Do not lean over the battery.
●In the event that battery fluid comes into contact with the skin or eyes, immediately
wash the affected area with water and seek medical attention.
Place a wet sponge or cloth over the affected area until medical attention can be
received.
●Always wash your hands afte r handling the battery support, terminals, and other bat-
tery-related parts.
●Do not allow childre n near the battery.
NOTICE
■When handling jumper cables
When connecting the jumper cables, ensure that they do not become entangled in the
cooling fans or engine drive belt.

5798-2. Steps to take in an emergency
8
When trouble arises
IS350 AWD/IS350/IS300 AWD/IS300_U
●The needle of the engine coolant temperature gauge (P. 89) enters 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.
After the engine has cooled down
sufficiently, insp ect 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

5818-2. Steps to take in an emergency
8
When trouble arises
IS350 AWD/IS350/IS300 AWD/IS300_U
Add coolant if necessary.
Water can be used in an emergency 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 fans 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.
Check if “Engine Coolant Temp High St op in a Safe Place See Owner’s Man-
ual” is shown on the multi-information display.
If the message does not disappear:
Stop the engine and contact your Lexus dealer.
If the message is not displayed:
Have the vehicle inspected at the nearest Lexus dealer.
5
Engine (IS350 AWD/IS350/
IS300 AWD)Engine (IS300)
Intercooler (IS300)
6
7
8

5828-2. Steps to take in an emergency
IS350 AWD/IS350/IS300 AWD/IS300_U
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.
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 foreig n matter (such as sand or dust etc.).
●Do not use any coolant additive.
●IS350 AWD/IS350/IS300 AWD: Do notloosen the coolant inlet cap or coolant reser-
voir cap while the engine and radiator are hot.
(The coolant inlet cap is located under the
engine cover.)
High temperature steam or coolant could
spray out.
●IS300: Do not loosen the coolant inlet cap,
coolant reservoir cap, or intercooler reser-
voir cap while the engine and radiator are hot.
High temperature steam or coolant could
spray out.

5929-1. Specifications
IS350 AWD/IS350/IS300 AWD/IS300_U
*: The fluid capacity is a reference quantity. If replacement is necessary, contact your Lexus dealer.
Cooling system
Capacity*
IS350 AWD/
IS350/IS300
AWD 9.9 qt. (9.4 L, 8.3 Imp. qt.)
IS300
Engine
8.2 qt. (7.8 L, 6.9 Imp. qt.)
Intercooler
3.2 qt. (3.0 L, 2.6 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 tech-
nology
Do not use plain water alone.
Ignition system (Spark plug)
IS350 AWD/IS350/ IS300 AWDIS300
Make DENSO FK20HBR8 NGK 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
(Check the voltage 20 minutes after the engine and all
lights are turned off.)
If the voltage is lower than the standard value, charge
the battery.
Charging rates5 A max.