1998 Lexus LS400 check engine

MAINTENANCE
216Parking brake
Check that the pedal has the proper travel and that, on a safe incline,
your vehicle is held securely with only the parking brake applied.
Automatic transmission ”Park” mechanism
On a safe incline, check that your vehicle is held securely with the
selector lever in ”P” position and all brakes released.
Engine compartment
Items listed below should be checked from time to time, e.g. each
time when refueling.
Washer fluid
Make sure there is sufficient fluid in the tank. See page 261 for
additional information.
Engine coolant level
Make sure the coolant level is between the Upper and Lower lines
on the seethrough reservoir when the engine is cold. See page 233
for additional information.
Battery
Your Lexus has a maintenance free battery. You do not have to add
distilled water. For longer life of the battery, however, see page 253
for additional information.
Brake fluid level
Make sure the brake fluid level is correct. See page 239 for
additional information.Engine oil level
Check the level on the dipstick with the engine turned off and the
vehicle parked on a level spot. See page 230 for additional
information.
Power steering fluid level
Check the level on the dipstick. The level should be in the ”HOT”
or ”COLD” range depending on the fluid temperature. See page 240
for additional information.
Exhaust system
Look for cracks, holes and loose supports. If you notice any change
in the sound of the exhaust or smell exhaust fumes, have the cause
located and corrected immediately. (See engine exhaust cautions in
Section 31.)

MAINTENANCE
217
DOES YOUR VEHICLE NEED
REPAIRING?
Be on the alert for changes in performance and sounds, and visual
tipoffs that indicate service is needed. Some important clues are:
Engine missing, stumbling, or pinging
Appreciable loss of power
Strange engine noises
A fluid leak under the vehicle (However, water dripping from the
air conditioning after use is normal.)
Change in exhaust sound (This may indicate a dangerous carbon
monoxide leak. Drive with the windows open and have the
exhaust system checked immediately.)
Flatlooking tires, excessive tire squeal when cornering, uneven
tire wear
Vehicle pulls to one side when driving straight on a level road
Strange noises related to suspension movement
Loss of brake effectiveness, spongy feeling brake pedal, pedal
almost touches floors, vehicle pulls to one side when braking
Engine coolant temperature continually higher than normal
If you notice any of these clues, take your vehicle to your Lexus
dealer as soon as possible. It probably needs adjustment or repair.
CAUTION
Do not continue driving with the vehicle unchecked. It could
result in serious vehicle damage and possibly personal injury.

INTRODUCTION
222Remember that battery and ignition cables carry high
currents or voltages. Be careful of accidentally causing a
short circuit.
Before closing the engine hood, check to see that you have not
forgotten any tools, rags, etc.
Do not drive with the air cleaner removed, or excessive engine
wear could result. Also backfiring could cause a fire in the
engine compartment.
Do not overfill automatic transmission fluid, or the
transmission could be damaged.
Be careful not to scratch the glass surface with the wiper
frame.
PARTS AND TOOLS
Here is a list of parts and tools you will need to perform
doityourself maintenance. Remember all Lexus parts are
designed in metric sizes, so your tools must be metric.
Checking the engine oil level
Parts (if level is low):
Use API grade SH, ”EnergyConserving II” or SJ,
”EnergyConserving” multigrade engine oil or ILSAC
multigrade engine oil. For recommended oil viscosity, see page
232.
Tools:
Rag or paper towel
Funnel (only for adding oil)
Checking the engine coolant level
Parts (if level is low):
Ethyleneglycol coolant
Demineralized or distilled water
Tools:
Funnel (only for adding coolant)

SECTION 6 2
224
SERVICE PROCEDURES AND
SPECIFICATIONS
Engine
Specifications 225. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel 227. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Facts about engine oil consumption 229. . . . . . . . . . . . . . . . . . . . . . . . . . .
Used engine oil 230. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the engine oil level 230. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the engine coolant level 233. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Spark plugs 234. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ENGINE
226 COOLING SYSTEM
Capacity
Coolant type
10.8 L (11.4 qt., 10.4 lmp.qt.)
Ethylene glycol coolant (Do not use alcohol type.)
FUEL
Fuel type
Octane rating
Only UNLEADED
91 (Research octane number 96) or higher
IGNITION SYSTEM
Spark plug Make DENSO
NGK
Gap
SK20R11
IFR6A11
1.1 mm (0.043 in.)
ELECTRICAL SYSTEM
Battery Maintenance type battery
Specific gravity reading at 20C (68F):
Charging rates Quick charge
Slow charge
Nonmaintenance battery
Open voltage at 20C (68F):
Charging rates
1.260 Fully charged
1.160 Half charged
1.060 Discharged
15A max.
5A max.
12.7V Fully charged
12.3V Half charged
11.9V Discharged
[Voltage that is checked 20 minutes after the key is removed with
all the lights turned off]
5A max.

ENGINE
229
FACTS ABOUT ENGINE OIL
CONSUMPTION
Functions of engine oil
Engine oil has the primary function of lubricating and cooling the
inside of the engine, and plays a major role in maintaining the engine
in proper working order.
Engine oil consumption
It is normal that an engine should consume some engine oil
during normal engine operation. The causes of oil consumption
in a normal engine are as follows.
Oil is used to lubricate pistons, piston rings and cylinders. A thin
film of oil is left on the cylinder wall when a piston moves
downwards in the cylinder. High negative pressure generated
when the vehicle is decelerating sucks some of this oil into the
combustion chamber. This oil as well as some part of the oil film
left on the cylinder wall is burned by the high temperature
combustion gases during the combustion process.
Oil is also used to lubricate the stems of the intake valves. Some
of this oil is sucked into the combustion chamber together with
the intake air and is burned along with the fuel. High temperature
exhaust gases also burn the oil used to lubricate the exhaust valve
stems.The amount of engine oil consumed depends on the viscosity of
the oil, the quality of the oil and the way the vehicle is driven.
More oil is consumed by highspeed driving and frequent
acceleration and deceleration.
A new engine consumes more oil, since its pistons, piston rings and
cylinder walls have not become conditioned.
When judging the amount of oil consumption, keep in mind that
the oil may have become diluted, making it difficult to judge the
true level accurately.
For example, if a vehicle is used for repeated short trips and
consumes a normal amount of oil, the dipstick may not show any
drop in the oil level at all, even after 1000 km (600 miles) or more.
This is because the oil is gradually becoming diluted with fuel or
moisture, making it appear that the oil level has not changed.
The diluting ingredients evaporate out when the vehicle is then
driven at high speeds, as on an expressway, making it appear that oil
is excessively consumed after driving at high speeds.
Importance of engine oil level check
One of the most important points in proper vehicle maintenance is
to keep the engine oil at the optimum level so that oil function will
not be impaired. Therefore, it is essential that the oil level be
checked regularly. Lexus recommends that the oil level be checked
every time you refuel the vehicle.
NOTICE

ENGINE
230Failure to check the oil level regularly could lead to serious
engine trouble due to insufficient oil.
For detailed information on oil level check, see ”Checking the
engine oil level” on page 230.
USED ENGINE OIL
CAUTION
Used engine oil contains potentially harmful contaminants
which may cause skin disorders such as inflammation or
skin cancer, so care should be taken to avoid prolonged and
repeated contact with it. To remove used engine oil from
your skin, wash thoroughly with soap and water.
Do not leave used oil within the reach of children.
Dispose of used oil and used oil filters only in a safe and
acceptable manner. Do not dispose of used oil and used oil
filters in household trash, in sewers or onto the ground.
Call your Lexus dealer or a service station for information
concerning recycling or disposal.
CHECKING THE ENGINE OIL
LEVEL
62L004-4
With the engine at operating temperature and turned off, check
the oil level on the dipstick.
1. To get a true reading, the vehicle should be on a level spot. After
turning off the engine, wait a few minutes for the oil to drain back
into the bottom of the engine.
2. Pull out the dipstick, and wipe it clean with a rag.
3. Reinsert the dipstick and push it in as far as it will go, or the
reading will not be correct.

ENGINE
231
62L002-1
1
Add oil 2
O.K. 3
Too full
4. Pull the dipstick out and look at the oil level on the end. If it is
between the full line (
5
) and the low line ( 4
), it is O.K.
62L003-3
If the oil level is below or only slightly above the low line, add
engine oil of the same type as already in the engine.Remove the oil filler cap and add engine oil a little at a time, checking
the dipstick. The approximate quantity of oil needed to fill between
the low line and the full line on the dipstick is indicated below for
reference.
When the level reaches within the correct range, return the filler cap
and turn the cap clockwise until you hear a click.
Oil quantity. L (qt., lmp. qt.) 1.5 (1.6, 1.3)
NOTICE
Avoid overfilling, or the engine could be damaged. Check the oil
level on the dipstick once again after adding the oil.