2007 Lexus GS450h engine coolant

5
When trouble arises
435
5-1. Essential information
If you think something is wrong
If you notice any of the following symptoms, your vehicle probably needs
adjustment or repair. Contact your Lexus dealer as soon as possible.
■ Visible symptoms
●Fluid leaks under the vehicle 
(Water dripping from the air conditioning after use is normal.)
● Flat-looking tires or uneven tire wear
● Engine coolant temper ature gauge needle continually points
higher than normal
■ Audible symptoms
●Changes in exhaust sound
● Excessive tire squeal when cornering
● Strange noises related to the suspension system
● Pinging or other noises related to the hybrid system
■ Operational symptoms
●Engine missing, stumbling or running rough
● 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, sp ongy feeling, pedal almost touches
the floor

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

490
6-1. Specifications
Cooling system
Ignition system
Capacity
Gasoline engine
Inverter9.8 qt. (9.3 L, 8.1 lmp.qt.)
3.0 qt. (2.9 L, 2.5 lmp.qt.)
Coolant type
Use either of the following:• “Toyota Super Long Life Coolant”
• Similar high-quality ethylene glycol-based non-sili-cate, non-amine, non-nitrite, and non-borate cool-
ant with long-life organic acid technology
Do not use plain water alone.
Spark plug
Make DENSO 
NGKFK20HBR11 
ILFR6D11T
Gap0.043 in. (1.1 mm)
NOTICE
■Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust gap when tuning engine.

503
6-1. Specifications
6
Vehicle specifications
Warning: The temperature grades for this tire are established for a tire that
is properly inflated and not overloaded.
Excessive speed, underinflation, or excess ive loading, either separately or in
combination, can cause heat build up and possible tire failure.
Glossary of tire terminology
Tire related termMeaning
Cold tire inflation pres-
sureTire pressure when the vehicle has been parked for
three hours or more, or has not been driven more
than 1 mile or 1.5 km under that condition
Maximum inflation pres-
sureThe maximum cold inflated pressure to which a tire
may be inflated, shown on the sidewall of the tire
Recommended inflation
pressureCold tire inflation pressure recommended by a man-
ufacturer
Accessory weight
The combined weight (in excess of those standard
items which may be replaced) of transmission, power
steering, power brakes, power windows, power seats,
radio and heater, to the extent that these items are
available as factory-installed equipment (whether
installed or not)
Curb weight
The weight of a motor vehicle with standard equip-
ment, including the maximum capacity of fuel, oil and
coolant, and if so equipped, air conditioning and
additional weight optional engine
Maximum loaded vehicle
weight
The sum of: 
(a) Curb weight 
(b) Accessory weight 
(c) Vehicle capacity weight 
(d) Production options weight
Normal occupant weight150 lb. (68 kg) times the number of occupants speci-
fied in the second column of Table 1
* that follows

520
Alphabetical index
Emergency, in case ofIf a warning light turns on ..............438
If a warning message is 
displayed ............................................ 444
If the hybrid system will not 
start.......................................................... 471
If the shift lever cannot be  shifted from P ....................................472
If the 12 volt battery is 
discharged ....................................... 476
If you have a flat tire .............. 460, 461
If you lose your keys......................... 473
If you think something is 
wrong ................................................... 435
If your vehicle becomes stuck.....483
If your vehicle needs to be 
towed ................................................... 428
If your vehicle overheats ............... 480
When the electronic key battery 
is discharged .................................... 474
Energy monitor............................................ 6
Engine Compartment .....................................369
Hood........................................................366
How to start the hybrid system ... 103
If the hybrid system will not 
start.......................................................... 471
Overheating........................................ 480
Power switch ........................................ 103
Engine compartment cover .............370
Engine coolant temperature 
gauge......................................................... 112
Engine/inverter coolant Capacity .................................................490
Checking ............................................... 376
Preparing and checking before winter ...................................... 176 Engine oil
Capacity ................................................ 489
Checking................................................. 371
Preparing and checking 
before winter...................................... 176
Engine oil maintenance data ........... 374
EPS (Electric Power Steering) .........164
Event data recorder ............................ 436
First-aid kit storage belt ..................... 327
Floor mats ................................................ 326
Fluid Brake ....................................................... 378
Washer................................................... 382
Fog lights Switch ........................................................ 125
Wattage ................................................. 494
Foot light .................................................. 304
Front passenger occupant 
classification system ............................. 77
Front passenger's seat belt 
reminder light ..................................... 440
Front seats Adjustment ...............................................33
Driving position memory ..................35
Front turn signal lights Wattage ................................................. 494
Fuel Capacity ................................................ 488
Fuel gauge ................................................ 112
Gas station information ................. 528
Information ........................................... 495
Refueling ................................................... 55
Messages .............................................. 456
Fuel filler door ........................................... 55
Fuses .......................................................... 403
F

526
What to do if...
What to do if...
A tire puncturesP. 4 6 0 /461If you have a flat tire
The hybrid system does not start
P. 5 9Hybrid vehicle immobilizer system
P. 4 7 1If the hybrid system will not start
P. 4 76If the 12 volt battery is discharged
The shift lever cannot be 
moved outP. 4 7 2If the shift lever cannot be shifted 
from “P”
The engine coolant temperature
gauge enters the red zone
Steam can be seen coming 
from under the hood
P. 4 8 0If your vehicle overheats
The key is lostP. 4 7 3If you lose your keys
The battery runs outP. 4 76If the 12 volt battery is discharged
The doors cannot be lockedP. 2 5Doors
The horn begins to soundP. 6 1Alarm
The vehicle is stuck in mud or
sandP. 4 8 3If the vehicle becomes stuck