| Regular clicking sound |
Sound increases as engine speed increases. |
- Valve mechanism is defective.
- Incorrect cam clearance
- Worn camshaft
- Broken valve spring
- Defective valve shim
|
| Heavy and dull clank |
Oil pressure is low. |
- Worn crankshaft bearing
- Worn connecting rod bearing
|
| Oil pressure is normal. |
- Loosened flywheel mounting bolt
- Damaged engine mounting
|
| High-pitched clank |
Sound is noticeable when accelerating with an overload condition. |
- Ignition timing advanced
- Accumulation of carbon inside combustion chamber
- Wrong heat range of spark plug
- Improper octane value gasoline
|
| Clank when engine speed is between 1, 000 and 2, 000 rpms. |
Sound is reduced when the fuel injector connector of the noisy cylinder is disconnected. |
- Worn crankshaft bearing
- Worn connecting rod bearing
|
| Knocking sound when engine is operating under idling speed and engine is warm |
Sound is reduced when the fuel injector connector of the noisy cylinder is disconnected. |
- Worn cylinder liner and piston ring
- Broken or stuck piston ring
- Worn piston pin and piton pin hole of piston
|
| Sound is not reduced if each fuel injector connector is disconnected in turn. |
- Unusually worn valve rocker
- Unusually worn valve shim
- Worn cam sprocket
- Worn journal of cam carrier and camshaft cap
|
| Squeaky sound |
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- Insufficient generator lubrication
|
| Rubbing sound |
- |
- Poor contact of generator brush and rotor
|
| Gear scream when starting engine |
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- Defective ignition starter switch
- Worn gear and starter pinion
|
| Sound like polishing glass with a dry cloth |
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- Defective automatic belt tensioner adjuster assembly (Loose V-belt)
- Defective water pump shaft
|
| Hissing sound |
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- Insufficient compression
- Air leakage in air intake system, hose, connection or manifold
|
| Timing chain noise |
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- Loose timing chain
- Timing chain contacting with adjacent part
|
| Valve noise |
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