2020 Lexus GS350 cooling

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GS350_GS F_OM_OM30J07U_(U)6-3. Do-it-yourself maintenance
The coolant level is satisfactory if it
is between the “FULL”/“F” and “LOW”/“L”
lines on the reservoir when the engine is cold.
■Engine coolant reservoir
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the “LOW” lin e, add coolant up to the “FULL” line.
(  P. 509)
■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 coolant, contact your Lexus dealer.
■If the coolant level drops within a short time of replenishing
Visually check the radiator, hoses, engine coolant reservoir caps, drain cock and water
pump.
If you cannot find a leak, have your Lexus de aler test the cap and check for leaks in the
cooling system.
Coolant
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GS350GS F

GS350_GS F_OM_OM30J07U_(U)
3896-3. Do-it-yourself maintenance
6
Maintenance and care
Check the radiator and condenser and clear away any foreign objects.
If either of the above parts is extremely dirty or you are not sure of their condi-
tion, have your vehicle inspected by your Lexus dealer.
WARNING
■When the engine is hot
Do not remove the engine coolant reservoir cap or the coolant inlet cap. ( P. 512)
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.
Radiator and condenser
WARNING
■When the engine is hot
Do not touch the radiator or condenser as they may be hot and cause serious injuries,
such as burns.

5087-2. Steps to take in an emergency
GS350_GS F_OM_OM30J07U_(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.

509
GS350_GS F_OM_OM30J07U_(U)
7
When trouble arises
7-2. Steps to take in an emergency
If your vehicle overheats
●The needle of the engine coolant temperature gauge (P. 92, 98) 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 is coming 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, inspect the hoses and cooling
core (radiator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant leaks,
immediately contact your Lexus
dealer.
The following may indicate that your vehicle is overheating.
Correction procedures
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5107-2. Steps to take in an emergency
GS350_GS F_OM_OM30J07U_(U)
The coolant level is satisfactory if it is between the “FULL”/“F” and “LOW”/“L”
lines on the reservoir.
Engine coolant reservoir
“FULL”/“F”
“LOW”/“L”
Coolant inlet cap
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 fans may not operate in freezing temperatures.)
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GS350GS F
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GS350GS F
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5127-2. Steps to take in an emergency
GS350_GS F_OM_OM30J07U_(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.
●GS350: Do not loosen the coolant inlet capor the engine coolant reservoir cap while the
engine and radiator are hot.
High temperature steam or coolant could
spray out.
●GS F: Do not loosen the engine coolant res-
ervoir cap while the engine and radiator are
hot.
High temperature steam or coolant could
spray out.

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GS350_GS F_OM_OM30J07U_(U)8-1. Specifications
Cooling system
CapacityGS3509.9 qt.(9.4 L, 8.3 Imp.qt.)
GS F11.9 qt. (11.3 L, 9.9 Imp.qt.)
Coolant typeUse 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
GS350GS F
Spark plug
Make
GapDENSO
FK20HBR8
0.031 in. (0.8 mm)DENSO
FK20HBR-J8
0.031 in. (0.8 mm)
NOTICE
■Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust the spark plug gap.

580Alphabetical index
GS350_GS F_OM_OM30J07U_(U)
Child restraint system............................ 59Booster seats, definition ....................59
Booster seats, installation.................. 67
Convertible seats, definition ............59
Convertible seats, installation .........65
Front passenger occupant classification system ......................... 52
Infant seats, definition ..........................59
Infant seats, installation .......................65
Installing CRS with LATCH anchors ..................... 64
Installing CRS with seat belts ..........65
Installing CRS with top tether strap .........................68
Child safety ................................................ 58 Airbag precautions .............................. 44
Battery precautions .............392, 508
Child restraint system .........................59
How your child should wear the seat belt ................................. 37, 38
Installing child restraints..................... 63
Moon roof precautions.................... 186
Power window lock switch .............. 181
Power window precautions .......... 183
Rear door child-protectors ........... 146
Removed electronic key battery precautions.................412
Seat belt comfort guide ..................... 37
Seat belt extender precautions ......40
Seat belt precautions .......................... 62
Seat heater precautions.................. 332
Trunk precautions............................... 152 Child-protectors .................................... 146
Cleaning ....................................... 362, 367
Aluminum wheels .............................. 363
Exterior ................................................... 362
Interior ..................................................... 367
Seat belts................................................368
Clock................................................. 93, 347
Coat hooks ............................................. 352
Condenser.............................................. 389
Console box ............................................. 341
Console box light ................................... 341
Consumption screen ............................ 134
Cooling system ..................................... 388 Engine overheating ......................... 509
Consumption screen ............................ 133
Cruise control Cruise control ..................................... 278
Dynamic radar cruise control with full-speed range ................... 266
Cup holders.............................................342
Curtain shield airbags ............................ 42
Customizable features .......................542
Daytime running light system...........223
Defogger Front windshield................................. 324
Outside rear view mirrors ............ 324
Rear window........................................ 324
Differential Front differential ................................. 523
Rear differential................................... 524
D