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An engine is the part which creates the power of the vehicle. When an engine is broken, the vehicle stops operating. Therefore, maintenance of the engine is necessary.
These are the aspects of maintenance related to the engine.
Importance of engine oil change
If the engine oil is not changed
The reason why engine oil amount decreases
Engine oil decreases little by little even under normal conditions, as small fraction of oil burns are mixed with the fuel after lubricating. (Oil consumption)
Engine Oil Filter
What is an engine oil filter?
This is the part that removes the carbon, sludge and metal particles in the engine oil.
If the engine oil filter is not replaced:
If the filter is clogged, oil cannot flow through the filter. Then the relief valve opens and sends the dirty oil into the engine.
Cooling & Heater System
What is the cooling system?
This system keeps the temperature of the engine constant. Also, the hot coolant warms the air to adjust the passenger compartment temperature.
If the coolant leaks...
Not only does it cause overheating, but also it damages the engine itself.
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What is a radiator cap?
It allows the coolant to stay at a constant pressure to keep the boiling point of the coolant above 100�C. Also, it improves the cooling performance by making the temperature difference between the coolant and the air greater.
The pressure valve opens at high pressure to deliver the coolant to the reservoir tank. On the other hand, the vacuum valve opens at decreased pressure to draw the coolant back in from the reservoir tank.
Importance of radiator cap inspection
If it does not function properly, it causes overheating.
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What is coolant?
Replace the engine coolant according to the distance driven or amount of time because it is difficult to judge the level of deterioration just by looking at the surface.
Types of Toyota Coolants
Use the coolant mixed with water. However it freezes easily if it is not used in the appropriate concentration. Use the TLLC concentration appropriate for each region. Refer to the Owner's Manual for the appropriate concentration of TLL.
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What is a drive belt?
Drive belt drives the auxiliary mechanisms such as the alternator, power steering pum, and water pump.
If drive belt is damaged
Air Cleaner Element
Roles of air cleaner element
Removes dust, sand, etc. to clean the intake air to the engine.
If the air cleaner element becomes clogged...
The engine power output falls and fuel economy becomes worse as the amount of air taken into the engine decreases
What is valve clearance?
It ensures the proper timing of valve opening and closing even if each part expands because of heat.
Excessive valve clearance
It causes the symptoms such as abnormal noise from the engine (tappet noise).
Insufficient valve clearance
It causes symptoms such as slight engine vibration
Inspection/Adjustment interval (Not Applicable for engine w/ scheme type of valve Mech.)
Timing Belt (Chain)
What is a timing belt?
It transfers the rotational movement of the crankshaft to the camshafts in order for the valves to properly operate.
Importance of changing timing belt
It hardens due to the heat of the engine, and this can lead to cracking or causing the teeth to shear off because of the rubber material.
If timing belt breaks
The timing of the valve opening and closing is out of sync, and the engine stops operating. The piston interferes with the valves, and the valves bend.
What is a spark plug?
It sends sparks to ignite the air-fuel mixture which is compressed for burning.
Importance of replacement spark plug
If the spark plugs are not replaced
By the corner of the electrode wearing, a plug gap spreads out, the fuel economy becomes worse, and the power output falls.
What is a fuel filter?
It removes small impurities contained in the fuel through the filter.
If a fuel filter is not replaced?
When the filter is clogged, fuel volume decreases. Then problems occur, such as the loss of power output at high speeds, then a larger volume of fuel is required
The interval should be 1/2 if impure fuel is used
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What is a battery?
It plays these roles:
If battery is not inspected
Danger of short circuit
Fuel Tank Cap
What is a fuel tank cap?
It is a cap for the fuel tank.
Importance of inspecting the fuel tank cap
In the fuel tank, some fuel vaporizes, containing a large volume of poisonous HCs (Hydrocarbons).
PCV (Positive Crankcase Ventilation) Valve
What is a PCV valve?
It is one of the control devices for the Emission Control, and re-burns the blow-by gas.
Importance of inspection of PCV valve
If the PCV valve is clogged, the blow-by gas is not taken into the intake manifold, and is released into the air. It also mixes with the engine oil and deteriorates the quality of oil.
Inspection intervalInspection: every 20,000km (12,000 miles) or 1 year
This contains a large amount of unburned gas (HC), which blows from the gap between the piston ring and the cylinder wall out to the crankcase.back to top
What is a charcoal canister?
This device prevents evaporated gas from the fuel tank from escaping into the atmosphere.
Importance of inspection of charcoal canister
When the check valve sticks, it stops operating correctly. Then the evaporated gas is released into the atmosphere
Inspection: every 40,000km (24,000 miles) or 2 years
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What is an idle mixture?
The air-fuel mixture is adjusted during idling to keep engine operation stable.
If idle mixture is wrong
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Maintained by I.T. Division, Toyota Otis, Inc.