Page 454 of 688
4546-3. Do-it-yourself maintenance
GS350_250_OM_OM30E16E_(EE)
Engine compartment
For right-hand drive vehicles:
The battery and the fuse box in front of the battery are located on the opposite side
of the engine compartment.
Fuse boxes (→P. 4 9 2 )
Battery ( →P. 4 6 1 )
Engine oil level dipstick (→ P. 4 5 6 )
Engine coolant reservoir (→ P. 4 5 9 ) Engine oil filler cap (
→P. 4 5 7 )
Washer fluid tank ( →P. 465)
Electric cooling fans
Condenser ( →P. 4 6 1 )
Radiator ( →P. 4 6 1 )1
2
3
4
5
6
7
8
9
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Page 459 of 688

459 6-3. Do-it-yourself maintenance
6
Maintenance and care
GS350_250_OM_OM30E16E_(EE)
The coolant level is satisfactory if it is between the “FULL” and “LOW”
lines on the reservoir when the engine is cold.Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the “LOW”
line, add coolant up to the “FULL” line.
(→ P. 6 2 5 )
■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.
“Toyota Super Long Life Coolant” is a mixture of 50% coolant and 50% deionized
water. (Minimum temperature: -35 °C [-31 °F])
For more details about engine coolant, contact any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
■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 any authorized Lexus dealer or repairer, or another
duly qualified and equipped professional, test the cap and check for leaks in the
cooling system.
Engine coolant
1
2
3
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Page 460 of 688
4606-3. Do-it-yourself maintenance
GS350_250_OM_OM30E16E_(EE)
CAUTION
■When the engine is hot
Do not remove the engine coolant reservoir cap or the coolant inlet cap. (→P. 6 2 5 )
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 cooling. 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.
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Page 542 of 688

5427-2. Steps to take in an emergency
GS350_250_OM_OM30E16E_(EE)
If you think something is wrong
●Fluid leaks under the vehicle.
(Water dripping from the air conditioning after use is normal.)
●Flat-looking tires or uneven tire wear
●Engine coolant temperature gauge needle continually 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 feeling, pedal almost touches the
floor
If you notice any of the following symptoms, your vehicle probably
needs adjustment or repair. Contact any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional as soon as
possible.
Visible symptoms
Audible symptoms
Operational symptoms
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Page 625 of 688

625
7
7-2. Steps to take in an emergency
When trouble arises
GS350_250_OM_OM30E16E_(EE)
If your vehicle overheats
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 any autho-
rized Lexus dealer or repairer, or
another duly qualified and
equipped professional.
The following may indicate that your vehicle is overheating.
●The needle of the engine coolant temperature gauge ( →P. 99)
enters the red zone or a loss of engine power is experienced. (For
example, the vehicle speed does not increase.)
●Steam is coming from under the hood.
Correction procedures
1
2
3
1
2
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6267-2. Steps to take in an emergency
GS350_250_OM_OM30E16E_(EE)
The coolant level is satisfactory if it is between the “FULL” and “LOW”
lines on the reservoir.Reservoir“FULL”
“LOW”
Coolant inlet cap
Add coolant if necessary.
Water can be used in an emergency if
coolant is unavailable.
Start the engine and turn the air co nditioning system on to check that
the radiator 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 any authorized Lexus dealer
or repairer, or another duly qualified and equipped professional.
If the fans are operating:
Have the vehicle inspected at the nearest any authorized Lexus dealer
or repairer, or another duly qualified and equipped professional.
4
1
2
3
4
5
6
7
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6277-2. Steps to take in an emergency
7
When trouble arises
GS350_250_OM_OM30E16E_(EE)
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 serious 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 additives.
●Do not loosen the coolant inlet cap or the
coolant reservoir cap while the engine and
radiator are hot.
High temperature steam or coolant could
spray out.
GS350_250_OM_OM30E16E_(EE).book Page 627 Tuesday, July 8, 2014 7:11 PM
Page 642 of 688
6428-1. Specifications
GS350_250_OM_OM30E16E_(EE)
Cooling system
GS250
GS350Left-hand drive
vehiclesRight-hand
drive vehicles
Capacity10.9 L (11.5 qt.,
9.6 I m p . q t . )11.0 L (11.6 qt.,
9.7 I m p.q t.)9.7 L ( 1 0. 3 q t . ,
8.5 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
Spark plug
Make
GapDENSO FK20HBR11
1.1 mm (0.043 in.)
NOTICE
■Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust the spark plug gap.
GS350_250_OM_OM30E16E_(EE).book Page 642 Tuesday, July 8, 201 4 7:11 PM