|
Type of sound |
Condition |
Possible cause |
|
Regular clicking sound |
Sound increases as engine speed increases. |
• Valve mechanism is defective. • Incorrect valve clearance • Worn valve rocker • Worn camshaft • Broken valve spring |
|
Heavy and dull clank |
Oil pressure is low. |
• Worn crankshaft main bearing • Worn connecting rod bearing (large end) |
|
Oil pressure is normal. |
• Damaged engine mounting • Loosened flywheel mounting bolt | |
|
High-pitched clank (Spark knock) |
Sound is noticeable when accelerating with an overload condition. |
• Ignition timing advanced • Accumulation of carbon inside combustion chamber • Wrong spark plug • Improper gasoline |
|
Clank when engine speed is 1,000 to 2,000 rpm |
Sound is reduced when fuel injector connector of noisy cylinder is disconnected. (NOTE*) |
• Worn crankshaft main bearing • Worn connecting rod bearing (large end) |
|
Knocking sound when engine is operating under idling speed and engine is warm |
Sound is reduced when fuel injector connector of noisy cylinder is disconnected. (NOTE*) |
• Worn cylinder liner and piston ring • Broken or stuck piston ring • Worn piston pin and hole at piston end of connecting rod |
|
Sound is not reduced if each fuel injector connector is disconnected in turn. (NOTE*) |
• Worn cam sprocket • Worn camshaft journal bore in cylinder head | |
|
Squeaky sound |
— |
Insufficient generator lubrication |
|
Rubbing sound |
— |
Poor contact of generator brush and rotor |
|
Gear scream when starting engine |
— |
• Defective ignition starter switch • Worn gear and starter pinion |
|
Sound like polishing glass with a dry cloth |
— |
• Loose V-belt • Defective water pump shaft |
|
Hissing sound |
— |
• Insufficient compression • Air leakage in air intake system, hose, connection or manifold |
|
Timing belt noise |
— |
• Loose timing belt • Belt contacting with case/adjacent part |
|
Valve noise |
— |
Incorrect valve clearance |
NOTE*)
When disconnecting the fuel injector connector, the malfunction indicator light illuminates and DTC is stored in ECM memory.
Therefore, after connecting the fuel injector connector, execute Clear Memory Mode and Inspection Mode. 
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