2018 Lexus GS350 engine coolant

4497-2. Steps to take in an emergency
GS350_300_GS F_OM_OM30G34U_(U)
7
When trouble arises
Indicates that the engine coolant temperature is too high A buzzer also sounds.
→ P. 509
(GS350/GS300 only)
Indicates a malfunction in the vehicle’s charging system.
→Immediately stop the vehicle in a safe place and
contact your Lexus dealer. Continuing to drive the
vehicle may be dangerous.
(If equipped)
Indicates that the radar sensor is dirty or covered with
ice A buzzer also sounds.
→ Clean the sensor.
Warning messageDetails/Actions

509
GS350_300_GS F_OM_OM30G34U_(U)
7
When trouble arises
7-2. Steps to take in an emergency
If your vehicle overheats
●The needle of the engine coolant temperature gauge (→P. 86, 92) enters the
red zone or a loss of engine power is experienced. (For example, the vehicle
speed does not increase.)
●“Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” is
shown on the multi-information display.
●Steam is coming from under the hood.
Stop the vehicle in a safe place and tu rn 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 cooling
core (radiator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant leaks,
immediately contact your Lexus
dealer.
The following may indicate that your vehicle is overheating.
Correction procedures
1
2
3
1
2

5107-2. Steps to take in an emergency
GS350_300_GS F_OM_OM30G34U_(U)
The coolant level is satisfactory if it is between the “FULL”/“F” and “LOW”/“L”
lines on the reservoir.
Engine coolant reservoir
“FULL”/“F”
“LOW”/“L”
Coolant inlet cap
Intercooler coolant reservoir4
1
2
3
4
5
GS350GS F
GS300

5117-2. Steps to take in an emergency
GS350_300_GS F_OM_OM30G34U_(U)
7
When trouble arises
Add coolant if necessary.
Water can be used in an emerge ncy if coolant is unavailable.
Start the engine and turn the air conditio ning system on to check that the radi-
ator 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 an d contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the nearest Lexus dealer.
5
GS350GS F
GS300
6
7

5127-2. Steps to take in an emergency
GS350_300_GS F_OM_OM30G34U_(U)
■When adding engine coolant (GS350/GS300)
Add coolant in accordance with the following procedure. Remove caps A and B.
Add engine coolant through the inlet of cap A up to the “[AR/GR] B” line, and then
install cap A.
Add engine coolant through the inlet of cap B until it is full, and then install cap B.
GS300 only: When inst alling cap B, apply coolant to the O-ring on the end of cap B.
Cap A
Cap B
“[AR/GR] B” line (Target fill line)
1
2
3
GS350 GS300
1
2
3

5137-2. Steps to take in an emergency
GS350_300_GS F_OM_OM30G34U_(U)
7
When trouble arises
WARNING
■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 h ood, 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 seri-
ous injury.
●GS350: Do not loosen the coolant inlet cap
or the engine coolant reservoir cap while the
engine and radiator are hot.
High temperature steam or coolant could
spray out.
●GS F: Do not loosen the engine coolant res-
ervoir cap while the engine and radiator are
hot.
High temperature steam or coolant could
spray out.
●GS300: Do not loosen the coolant inlet cap,
the engine coolant rese rvoir cap or the inter-
cooler coolant reservoir cap while the engine
and radiator are hot.
High temperature steam or coolant could
spray out.

5147-2. Steps to take in an emergency
GS350_300_GS F_OM_OM30G34U_(U)
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 foreig n matter (such as sand or dust etc.).
●Do not use any coolant additive.

GS350_300_GS F_OM_OM30G34U_(U)
5258-1. Specifications
8
Vehicle specifications
Cooling system
Capacity
GS3509.9 qt.(9.4 L, 8.3 Imp.qt.)
GS300
Engine coolant
9.5 qt.(9.0 L, 7.9 Imp.qt.)
Intercooler
2.7 qt.(2.6 L, 2.3 Imp.qt.)
GS F11.9 qt. (11.3 L, 9.9 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
GS350GS300GS F
Spark plug
Make
GapDENSO
FK20HBR8
0.031 in. (0.8 mm)NGK
DILFR7K9G
0.04 in. (0.9 mm)DENSO
FK20HBR-J8
0.031 in. (0.8 mm)
NOTICE
■Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust the spark plug gap.