2007 Lexus GS450h radiator

359
4-2. Maintenance
4
Maintenance and care
General maintenance
Engine compartment
Luggage compartment
ItemsCheck points
Brake fluid• At the correct level? (P. 3 7 8 )
Engine/inverter coolant• At the correct level? ( P. 3 76 )
Engine oil• At the correct level? ( P. 3 7 1 )
Exhaust system• No fumes or strange sounds?
Radiator/condenser/hoses• Not blocked with foreign matter? 
( P. 3 7 7 )
Wa s h e r f l u i d• At the correct level? ( P. 3 8 2 )
ItemsCheck points
12 volt battery• Maintenance-free ( P. 3 7 9 )
Listed below are the general maintenance items that should be performed
at the intervals specified in the “Warranty and Services Guide/Owner’s
Manual Supplement”. It is recommend ed that any problem you notice
should be brought to the attention of your Lexus dealer or qualified service
shop for advice.

364
4-3. Do-it-yourself maintenance
CAUTION
The engine compartment contains many mechanisms and fluids that may move sud-
denly, become hot, or become electrically energized. To avoid death or serious injury.
■When working on the engine compartment:
●Keep hands, clothing, and tools away from the moving fan and engine drive belt.
●Be careful not to touch the engine, inverter, radiator, exhaust manifold, etc. right
after driving as they may be hot. Oil and other fluids may also be hot.
●Do not leave anything that may burn easily , such as paper or rags, in the engine
compartment.
●Do not smoke, cause sparks or expose an open flame to fuel or the battery. Fuel
and battery fumes are flammable.
●Be extremely cautious when working on the battery. It contains poisonous and
corrosive sulfuric acid.
ItemsPa r t s a n d t o o l s
Engine oil level ( P. 3 7 1 )
• “Toyota Genuine Motor Oil” or
equivalent
• Rag or paper towel, funnel (used
only for adding engine oil)
Fuses ( P. 4 0 3 )• Fuse with same amperage rating as
original
Headlight aim ( P. 4 1 9 )• Phillips-head screwdriver
Radiator and condenser (P. 377)
Tire inflation pressure ( P. 393)• Tire pressure gauge
• Compressed air source
Wa s h e r f l u i d ( P. 3 8 2 )
• Water washer fluid containing anti-
freeze (for winter use)
•Funnel

365
4-3. Do-it-yourself maintenance
4
Maintenance and care
CAUTION
■When working near the electric cooling fan or radiator grille
Be sure the power switch is “OFF”.
With the power switch in “IG-ON” mode, the electric cooling fan may automati-
cally start to run if the air conditioning is on and/or the coolant temperature is high. 
(  P. 377)
■Safety glasses
Wear safety glasses to prevent flying or fall ing material, fluid spray, etc. from getting
in the eyes.
NOTICE
■If you remove the air cleaner filter
Driving with the air cleaner filter removed may cause excessive engine wear due to
dirt in the air. Also a backfire could cause a fire in the engine compartment.

369
4-3. Do-it-yourself maintenance
4
Maintenance and care
Engine compartment
■12 volt battery
P. 3 7 9
Engine oil level dipstick 
( P. 371)
Engine oil filler cap 
( P. 3 7 2 )
Brake fluid reservoir (P. 3 7 8 )
Fuse box ( P. 403)Washer fluid tank 
( P. 382)
Gasoline engine/inverter 
coolant reservoir ( P. 3 76 )
Electric cooling fans
Condenser ( P. 377)
Radiator ( P. 377)

376
4-3. Do-it-yourself maintenance
CoolantThe coolant level is satisfactory if it is between the “FULL” and “LOW”
lines on the reservoir when the hybrid system is cold.
Reservoir cap
“FULL”
“LOW”
If the level is on or below the
“LOW” line, add coolant up to the
“FULL” line.
■If the coolant level drops within a short time after replenishing
Visually check the radiator, hoses, reservoir cap, radiator cap, drain cock and water
pump. 
If you cannot find a leak, have your Lexus dealer pressure test the cap and check for
leaks in the cooling system.
■Coolant selection
Only use “Toyota Super Long Life Coolant” or 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 mixture of 50% coolant and 50%
deionized water. (Enabled: -31F [-35 C])
Canada: “Toyota Super Long Life Coolant” is a mixture of 55% coolant and 45% deionized water. (Enabled: -44 F [-42C])
For more details about engine/inverter coolant, contact your Lexus dealer.

377
4-3. Do-it-yourself maintenance
4
Maintenance and care
Radiator and condenserCheck the radiator and condenser and clear any foreign objects. 
If either of the above parts are extremely dirty or you are not sure of their
condition, have your vehicle checked by your Lexus dealer.
CAUTION
■When the coolant may be hot
Do not remove the radiator cap. 
The cooling system may be under pressure and may spray hot coolant if the cap is
removed, causing burns or other injuries.
NOTICE
■When adding the coolant
Coolant is neither plain water not straight antifreeze. The correct mixture of water
and anti freeze 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 damage to parts or paint.
CAUTION
■The radiator and condenser may be hot after driving
To prevent burns, do not touch the radiator or condenser after driving.

480
5-2. Steps to take in an emergency
If your vehicle overheats
■Electric motor (traction motor) and inverter
If the message “HYBRID SYSTEM OVERHEAT” is displayed on the
multi-information display.
■ Gasoline engine
If the needle of the engine co olant temperature gauge enters the
red zone, the gasoline engine has probably overheated.
Observe the following steps:
Stop the vehicle in a safe place and turn off the automatic air
conditioning system.
Check to see if steam is coming out from under the hood.
If you see steam: 
Stop the hybrid system and carefully lift the hood.
If you do not see steam: Leave the hybrid system running and carefully lift the hood.
Remove the engine compartment cover. ( P. 370)
Check to see if the cooling fan is operating.
If the fan is operating: 
Wait until the engine coolant temperature gauge begins to
fall and then stop the hybrid system.
If the fan is not operating: 
Stop the hybrid system immed iately and call your local
Lexus dealer.
After the hybrid system has
cooled down sufficiently, check
the coolant level and inspect the
radiator core (radiator) for any
leaks.
STEP1
STEP2
STEP3
STEP4
STEP5

5
When trouble arises
481
5-2. Steps to take in an emergency
■Overheating
In the following situations, your vehicle may be overheating.
●The message “HYBRID SYSTEM OVERHEAT” is displayed on the multi-infor-
mation display.
●The engine coolant temperature gauge enters the red zone or a loss of power is
experienced.
●Steam is coming from under the hood.
CAUTION
■To prevent an accident or injury when in specting under the hood of your vehicle
●Keep hands and clothing away from the fan and engine drive belt while the hybrid
system is running.
●Do not loosen the radiator cap while the hybrid system and radiator are hot. 
Serious injury, such as burns, may resu lt from hot coolant and steam released
under pressure.
Add coolant if required.
Water can be used in an emer-
gency measure if coolant is
unavailable. ( P. 4 9 0 )
Have the vehicle checked at your nearest Lexus dealer as soon as pos-
sible.
STEP6