Subaru Legacy (2005 year). Manual — part 78

ME(H4SO 2.0)-95

MECHANICAL

Engine Noise

27.Engine Noise

A: INSPECTION

NOTE*)
When disconnecting the fuel injector connector, the malfunction indicator light illuminates and DTC is stored in ECM memory.
Therefore, carry out the clear memory mode <Ref. to EN(H4SO 2.0)(diag)-38, OPERATION, Clear Memory Mode.> <Ref. to
EN(H4SO 2.5)(diag)-40, OPERATION.> and inspection mode <Ref. to EN(H4SO 2.0)(diag)-32, PROCEDURE, Inspection
Mode.> <Ref. to EN(H4SO 2.5)(diag)-2, PROCEDURE.> after connecting the fuel injector connector.

Type of sound

Condition

Possible cause

Regular clicking sound

Sound increases as engine
speed increases.

• Defective valve mechanism
• Incorrect valve clearance
• Worn valve rocker
• Worn camshaft
• Broken valve spring

Heavy and dull clank

Oil pressure is low.

• Worn camshaft main bearing
• Worn connecting rod bearing (large end)

Oil pressure is normal.

Damaged engine mounting

High-pitched clank (Spark
knock)

Sound is noticeable when
accelerating with an overload.

• 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 cyl-
inder is disconnected.
(NOTE*)

• Worn camshaft main bearing
• Worn bearing at crankshaft end of connecting rod

Knocking sound when engine
is operating under idling speed
and engine is warm

Sound is reduced when fuel
injector connector of noisy cyl-
inder 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 dis-
connected in turn. (NOTE*)

• Worn cam sprocket
• Worn camshaft journal bore in cylinder head assembly

Squeaky sound

—

Insufficient generator lubrication

Rubbing sound

—

Defective generator brush and rotor contact

Gear scream when starting
engine

—

• Defective ignition starter switch
• Worn gear and starter pinion

Sound like polishing glass with
a dry cloth

—

• Loose drive belt
• Defective water pump shaft

Hissing sound

—

• Insufficient compression
• Air leakage in air intake system, hoses, connections or mani-
folds

Timing belt noise

—

• Loose timing belt
• Belt contacting with case/adjacent part

Valve tappet noise

—

Incorrect valve clearance

ME(H4SO 2.0)-96

MECHANICAL

Engine Noise

EXHAUST

EX(H4SO 2.0)

Page

1.

General Description . . . . . . . . . . . . . . . . . . . . . 2

2.

Front Exhaust Pipe. . . . . . . . . . . . . . . . . . . . . ..6

3.

Center Exhaust Pipe . . . . . . . . . . . . . . . . . . . . ...9

4.

Rear Exhaust Pipe . . . . . . . . . . . . . . . . . . . . . 10

5.

Muffler . . . . . . . . . . . . . . . . . . . . . . . . . ...12

EX(H4SO 2.0)-2

EXHAUST

General Description

1. General Description

A: COMPONENT

• 2.0 L model

EX-02102

T7

(19)

(20)

(21)

(22)

(19)

(19)

(18)

(17)

(16)

(15)

(14)

(8)

(8)

T3

T1

T2

T5

T1

T4

T4

T1

T1

(13)

(1)

(2)

(7)

T3

T1

(5)

(10)

(23)

(24)

(4)

(11)

(6)

(3)

(9)

(12)

T6