448
2008 TUNDRA from Apr. ’08 Prod. (OM 34477U)
Do not leave the engine running in
an area with snow build up, or
where it is snowing. If snowbanks
build up around the vehicle while
the engine is running, exhaust
gases may collect and enter the ve-
hicle. This may lead to death or a
serious health hazard.
When taking a nap in the vehicle,
always turn the engine off. Other-
wise, you may accidentally move
the shift lever or depress the accel-
erator pedal, which could cause an
accident or fire due to engine over-
heating. Additionally, if the vehicle
is parked in a poorly ventilated
area, exhaust gases may collect and
enter the vehicle, leading to death
or a serious health hazard.
Toyota does not recommend occu-
pying the rear cargo area when it
is fitted with a slide in camper,
camper shell or other type cover
while the engine is running. This
caution applies to both driving and
stopped or parked situations with
the engine running. Particular care
should be taken to prevent exhaust
gases from entering camper bodies,
trailers or other enclosures on or
around your vehicle. If exhaust
fumes are detected, open all win-
dows and thoroughly ventilate the
area.FUNCTIONS OF ENGINE OIL
Engine oil has the primary functions of
lubricating and cooling the inside of the
engine, and plays a major role in main-
taining the engine in proper working order.
ENGINE OIL CONSUMPTION
It is normal that an engine should con-
sume 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 pis-
ton 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 tem-
perature exhaust gases also burn the
oil used to lubricate the exhaust valve
stems.
Facts about engine oil
consumption
449
2008 TUNDRA from Apr. ’08 Prod. (OM 34477U)
The amount of engine oil consumed de-
pends on the viscosity of the oil, the
quality of the oil and the conditions the
vehicle is driven under.
More oil is consumed by high −speed driv-
ing and frequent acceleration and decel-
eration.
A new engine consumes more oil, since
its pistons, piston rings and cylinder walls
have not become conditioned.
When judging the amount of oil con-
sumption, note that the oil may become
diluted and make it difficult to judge
the true level accurately.
As an example, if a vehicle is used for
repeated short trips, and consumes a nor-
mal 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 prop-
er vehicle maintenance is to keep the en-
gine oil at the optimum level so that oil
function will not be impaired. Therefore, it
is essential that the oil level be checked
regularly. Toyota recommends that the oil
level be checked every time you refuel
the vehicle.
NOTICE
Failure 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 548 in Section 7
−2.
CY20008a
Your engine is fitted with iridium tipped
spark plugs.
NOTICE
Use only iridium tipped spark plugs.
Do not adjust gaps for engine perfor-
mance smooth driveability.
Iridium tipped spark plugs [4.7
L V8 (2UZ FE) engine]
