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Home >> Subaru >> 2021 >> Crosstrek Base, Standard Trans >> Repair and Diagnosis >> Engine Mechanical >> Mechanical >> Engine Mechanical System >> Engine Noise >> Inspection

Engine Noise: Inspection

Type of sound Condition Possible cause
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 noise when engine speed is (1, 000 - 2, 000 r/min) Sound is reduced when the fuel injector of the noisy cylinder is stopped.(1)
  • 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 of the noisy cylinder is stopped.(1)
  • 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 is stopped in turn.(1)
  • Unusually worn valve rocker
  • Unusually worn valve shim
  • Worn cam sprocket
  • Worn journal of cam carrier and camshaft cap
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 -
  • Defective V-belt tensioner assembly (loose V-belt)
  • Defective water pump shaft
Hissing sound -
  • Insufficient compression
  • Air leakage in air intake system, hose, connection or manifold
Timing chain noise -
  • Loose timing chain
  • Timing chain contacting with adjacent part
Valve noise -
  • Incorrect cam clearance
(1) Fuel injector can be stopped using the Subaru Select Monitor.

2.0 L gasoline engine model: 

Ref. to ENGINE (DIAGNOSTICS) (H4DO 2.0 (EXCEPT FOR HEV))>ACTIVE TEST>OPERATION .

2.5 L model: 

Ref. to ENGINE (DIAGNOSTICS) (H4DO 2.5)>ACTIVE TEST>OPERATION .

Hybrid model: 

Ref. to ENGINE (DIAGNOSTICS) (H4DO(HEV))>ACTIVE TEST>OPERATION .

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