2008 Lexus IS250 cooling

288
4-3. Do-it-yourself maintenance
08_IS350/250_U_(L/O_0708)
CAUTION
■When working near the electric cooling fan or radiator grille:
Be sure the “ENGINE START STOP” switch is OFF.
With the “ENGINE START STOP” switch in IGNITION ON mode, the electric
cooling fan may automatically start to run if the air conditioning is on and/or the
coolant temperature is high.
(
→P. 3 0 1 )
■Safety glasses
Wear safety glasses to prevent flying or falling material, fluid spray, etc. from getting
in the eyes.
NOTICE
■If you remove the air cleaner:
Driving with the air filter removed may cause excessive engine wear due to dirt in
the air. Also a backfire could cause a fire in the engine compartment.

292
4-3. Do-it-yourself maintenance
08_IS350/250_U_(L/O_0708)
Engine compartment
IS350
Battery (→P. 302)
Engine oil level dipstick (→P. 295)
Engine oil filler cap (→P. 295)
Brake fluid reservoir (→P. 301)
Fuse boxes ( →P. 327)Washer fluid tank
(→P. 305)
Electric cooling fans
Condenser ( →P. 3 0 1 )
Radiator ( →P. 3 0 1 )
Engine coolant reservoir (→P. 299)

293
4-3. Do-it-yourself maintenance
4
Maintenance and care
08_IS350/250_U_(L/O_0708)
IS250
Battery (→P. 302)
Engine oil level dipstick (→P. 295)
Engine oil filler cap (→P. 295)
Brake fluid reservoir (→P. 301)
Fuse boxes ( →P. 327)Washer fluid tank
(→P. 305)
Electric cooling fans
Condenser ( →P. 3 0 1 )
Radiator ( →P. 3 0 1 )
Engine coolant reservoir (→P. 299)

300
4-3. Do-it-yourself maintenance
08_IS350/250_U_(L/O_0708)
■If the coolant level drops within a short time after replenishing
Visually check the radiator, hoses, engine coolant filler 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 coolant, contact your Lexus dealer.
CAUTION
■When the engine is 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 engine 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 damaging parts or paint.

332
4-3. Do-it-yourself maintenance
08_IS350/250_U_(L/O_0708)
FuseAmpereCircuit
10E/G-B60 AFR CTRL-B, ETCS, ALT-S, steering
lock system, exhaust system
11DIESEL GLW80 A
12ABS150 AVSC, VDIM
13RH J/B-B30 APower door lock system, smart access
system with push-button start
14MAIN30 AHeadlight low beams
15STARTER30 ASmart access system with push-button
start
16LH J/B-B30 APower door lock system, SECURITY
17P/ I - B60 A
Multiport fuel injection system/
sequential multiport fuel injection sys-
tem
18EPS80 APo w e r s t e e r i n g
19ALT150 A
LH J/B-AM, E/G-AM, GLW PLG2,
HEATER, FAN1, FAN2, DEFOG,
ABS2, RH J/B-AM, GLW PLG1,
LH J/B-B, RH J/B-B
20GLW PLG150 APTC heater
21RH J/B-AM80 A
OBD, STOP SW, TI&TE, FR P/SEAT
RH, RAD NO.3, ECU-IG RH,
RH-IG, FR S/HTR RH, ACC, CIG,
PWR OUTLET
22ABS230 AVSC
23DEFOG50 ARear window defogger
24FA N 240 AElectric cooling fans
25FA N 140 AElectric cooling fans
26HEATER50 AAir conditioning system

5
When trouble arises
399
5-2. Steps to take in an emergency
08_IS350/250_U_(L/O_0708)
CAUTION
■Battery precautions
The battery contains poisonous and corrosive acidic electrolyte, while related parts
contain lead and lead compounds. Observe the following precautions when han-
dling the battery.
●When working with the battery, always wear safety glasses and take care not to
allow any battery fluids (acid) to come into contact with skin, clothing or the vehi-
cle body.
●Do not lean over the battery
●In the event that battery fluid comes into contact with the skin or eyes, immedi-
ately 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 after handling the battery support, terminals, and other
battery-related parts.
●Do not allow children near the battery.
NOTICE
■To prevent damaging the vehicle
Do not pull- or push-start the vehicle, because the three-way catalytic converter
may overheat and become a fire hazard.
■When handling jumper cables
Be careful that the jumper cables do not become tangled in the cooling fan or any
of the belts when connecting or disconnecting them.

400
5-2. Steps to take in an emergency
08_IS350/250_U_(L/O_0708)
If your vehicle overheats
If your engine overheats:
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 engine and carefully lift the hood.
If you do not see steam: Leave the engine running and carefully lift the hood.
Remove the engine compartment cover. ( →P. 2 9 4 )
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 cluster) begins to fall and then stop the engine.
If the fan is not operating: Stop the engine immediately and call your local Lexus
dealer.
After the engine has cooled
down sufficiently, check the
engine coolant level and inspect
the radiator core (radiator) for
any leaks.STEP1
STEP2
STEP3
STEP4
STEP5

411
6-1. Specifications
6
Vehicle specifications
08_IS350/250_U_(L/O_0708)
Cooling system
Ignition system
Capacity9.6 q t.
(9.1 L, 8.0 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 hybrid organic acid technology
Do not use plain water alone.
Spark plug
Make
GapDENSO FK20HBR11
0.043 in. (1.1 mm)
NOTICE
■Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust gap when tuning engine.