2008 LEXUS RX400H coolant

323
4-3. Do-it-yourself maintenance
4
Maintenance and care
RX400h_U
CoolantThe coolant level is satisfactory if it is between the FULL and LOW lines
on the reservoir when the hybrid system is cold. Engine coolant reservoir Reser voir cap
Full (upper line)
Low (lower line)
If the level is on or below the LOW
line, add coolant up to the FULL
line.
Power control unit coolant reservoir

324
4-3. Do-it-yourself maintenance
RX400h_U
■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 coolant, contact 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 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 damaging parts or paint.

5
When trouble arises
385
5-1. Essential information
RX400h_U
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 temperature 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

424
5-2. Steps to take in an emergency
RX400h_U
If your vehicle overheats
■Electric motor (traction motor) and inverter
If the message WATER TEMP is displayed on the multi-information
display.
■ Gasoline engine
If the needle of the engine coolant 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. Carefully lift the hood after the
steam subsides and then restart the hybrid system.
If you do not see steam: Leave the hybrid system running and carefully lift the hood.
Check to see if the cooling fan is operating.
If the fan is operating: Wait until the temperature of the engine (shown on the
instrument cluste r) begins to fall and then stop the hybrid
system.
If the fan is not operating: Stop the hybrid system immediately and call your local
Lexus dealer.
After the hybrid system has
cooled down sufficiently, check
the engine coolant level and
inspect the radiator core (radia-
tor) for any leaks.
STEP1
STEP2
STEP3
STEP4

5
When trouble arises
425
5-2. Steps to take in an emergency
RX400h_U
■Overheating
If you observe the following, your vehicle may be overheating.
●The message WATER TEMP is displayed on the multi-information 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 inspecting under the hood of your vehicle
●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, causing serious
injury such as burns.
●Keep hands and clothing away from the fan and other belts while the hybrid sys-
tem is running.
●Do not loosen the radiator cap while the hybrid system and radiator are hot.
Serious injury, such as burns, may result from hot coolant and steam released
under pressure.
Add engine coolant if required.
Water can be used in an emer-
gency measure if engine coolant
is unavailable. (→P. 4 3 5 )
Have the vehicle checked at your nearest Lexus dealer as soon as pos-
sible.
STEP5

426
5-2. Steps to take in an emergency
RX400h_U
NOTICE
■When adding engine coolant
Wait until the engine has cooled down before adding engine coolant.
When adding coolant, do so slowly. Adding cool coolant to a hot engine too quickly
can cause damage to the hybrid system.

435
6-1. Specifications
6
Vehicle specifications
RX400h_U
Cooling system
Ignition system
Capacity
Gasoline engine
power control unit10.9 qt. (10.3 L, 9.0 Imp.qt.)
3.6 qt. (3.4 L, 3.0 Imp.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
NGK
Gap
SK20R11
IFR6A11
0.043 in. (1.1 mm)
NOTICE
■Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust gap when tuning the gasoline
engine.

451
6-1. Specifications
6
Vehicle specifications
RX400h_U
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 automatic transmis-
sion, 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