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HOMESERVICE MANUALSSUBARU2005OUTBACK I, STANDARDREPAIR AND DIAGNOSISENGINE MECHANICALTIMING BELTENGINE MECHANICAL (H4SO)ENGINE TROUBLE IN GENERALINSPECTION

2005 Subaru Outback i, Standard

Engine Trouble in General: Inspection

2005 Subaru Outback i, StandardSECTION Inspection

NOTE: "RANK" shown in DIAGNOSTIC REFERENCE ENGINE TROUBLE refers to the possibility of reason for the trouble in order ("Very often" to "Rarely")

DIAGNOSTIC REFERENCE ENGINE TROUBLE

Symptom

Problem parts, etc.

Possible cause

RANK

1. Engine does not start.

a) Starter does not turn.

Starter

Defective battery-to-starter harness

⁽²⁾

Defective starter switch

⁽³⁾

Defective inhibitor switch

⁽³⁾

Defective starter

⁽²⁾

Battery

Poor terminal connection

⁽¹⁾

Run-down battery

⁽¹⁾

Defective charging system

⁽²⁾

Friction

Seizure of crankshaft and connecting rod bearing

⁽³⁾

Seized camshaft

⁽³⁾

Seized or stuck piston and cylinder

⁽³⁾

b) Initial combustion does not occur.

Starter

Defective starter

⁽³⁾

Engine control system < Ref. to BASIC DIAGNOSTIC PROCEDURE . >

⁽¹⁾

Fuel line

Defective fuel pump and relay

⁽¹⁾

Lack of or insufficient fuel

⁽²⁾

Belt

Trouble

⁽²⁾

Defective timing

⁽²⁾

Compression

Incorrect valve clearance

⁽³⁾

Loosened spark plug or defective gasket

⁽³⁾

Loosened cylinder head bolt or defective gasket

⁽³⁾

Improper valve sealing

⁽³⁾

Defective valve stem

⁽³⁾

Worn or broken valve spring

⁽²⁾

Worn or stuck piston rings, cylinder and piston

⁽³⁾

Incorrect valve timing

⁽²⁾

Improper engine oil (low viscosity)

⁽²⁾

c) Initial combustion occurs.

Engine control system < Ref. to BASIC DIAGNOSTIC PROCEDURE . >

⁽¹⁾

Intake system

Defective intake manifold gasket

⁽²⁾

Defective throttle body gasket

⁽²⁾

Fuel line

Defective fuel pump and relay

⁽³⁾

Clogged fuel line

⁽³⁾

Lack of or insufficient fuel

⁽²⁾

Belt

Trouble

⁽²⁾

Defective timing

⁽²⁾

Compression

Incorrect valve clearance

⁽³⁾

Loosened spark plug or defective gasket

⁽³⁾

Loosened cylinder head bolt or defective gasket

⁽³⁾

Improper valve sealing

⁽³⁾

Defective valve stem

⁽³⁾

Worn or broken valve spring

⁽²⁾

Worn or stuck piston rings, cylinder and piston

⁽³⁾

Incorrect valve timing

⁽²⁾

Improper engine oil (low viscosity)

⁽²⁾

d) Engine stalls after initial combustion.

Engine control system < Ref. to BASIC DIAGNOSTIC PROCEDURE . >

⁽¹⁾

Intake system

Loosened or cracked intake duct

⁽²⁾

Loosened or cracked PCV hose

⁽³⁾

Loosened or cracked vacuum hose

⁽³⁾

Defective intake manifold gasket

⁽²⁾

Defective throttle body gasket

⁽²⁾

Dirty air cleaner element

⁽³⁾

Fuel line

Clogged fuel line

⁽³⁾

Lack of or insufficient fuel

⁽²⁾

Belt

Trouble

⁽²⁾

Defective timing

⁽²⁾

Compression

Incorrect valve clearance

⁽³⁾

Loosened spark plug or defective gasket

⁽³⁾

Loosened cylinder head bolt or defective gasket

⁽³⁾

Improper valve sealing

⁽³⁾

Defective valve stem

⁽³⁾

Worn or broken valve spring

⁽²⁾

Worn or stuck piston rings, cylinder and piston

⁽³⁾

Incorrect valve timing

⁽²⁾

Improper engine oil (low viscosity)

⁽²⁾

2. Rough idle and engine stall

Engine control system < Ref. to BASIC DIAGNOSTIC PROCEDURE . >

⁽¹⁾

Intake system

Loosened or cracked intake duct

⁽¹⁾

Loosened or cracked PCV hose

⁽¹⁾

Loosened or cracked vacuum hose

⁽¹⁾

Defective intake manifold gasket

⁽²⁾

Defective throttle body gasket

⁽²⁾

Defective PCV valve

⁽³⁾

Loosened oil filler cap

⁽²⁾

Dirty air cleaner element

⁽³⁾

Fuel line

Defective fuel pump and relay

⁽³⁾

Clogged fuel line

⁽³⁾

Lack of or insufficient fuel

⁽²⁾

Belt

Defective timing

⁽³⁾

Compression

Incorrect valve clearance

⁽²⁾

Loosened spark plug or defective gasket

⁽²⁾

Loosened cylinder head bolt or defective gasket

⁽²⁾

Improper valve sealing

⁽²⁾

Defective valve stem

⁽³⁾

Worn or broken valve spring

⁽²⁾

Worn or stuck piston rings, cylinder and piston

⁽²⁾

Incorrect valve timing

⁽¹⁾

Improper engine oil (low viscosity)

⁽²⁾

Lubrication system

Incorrect oil pressure

⁽²⁾

Defective rocker cover gasket

⁽³⁾

Cooling system

Over-heating

⁽³⁾

Other

Evaporative emission control system malfunction

⁽¹⁾

Stuck or damaged throttle valve

⁽²⁾

3. Low output, hesitation and poor acceleration

Engine control system < Ref. to BASIC DIAGNOSTIC PROCEDURE . >

⁽¹⁾

Intake system

Loosened or cracked intake duct

⁽¹⁾

Loosened or cracked PCV hose

⁽¹⁾

Loosened or cracked vacuum hose

⁽²⁾

Defective intake manifold gasket

⁽²⁾

Defective throttle body gasket

⁽²⁾

Defective PCV valve

⁽²⁾

Loosened oil filler cap

⁽²⁾

Dirty air cleaner element

⁽¹⁾

Fuel line

Defective fuel pump and relay

⁽²⁾

Clogged fuel line

⁽²⁾

Lack of or insufficient fuel

⁽³⁾

Belt

Defective timing

⁽²⁾

Compression

Incorrect valve clearance

⁽²⁾

Loosened spark plug or defective gasket

⁽²⁾

Loosened cylinder head bolt or defective gasket

⁽²⁾

Improper valve sealing

⁽²⁾

Defective valve stem

⁽³⁾

Worn or broken valve spring

⁽²⁾

Worn or stuck piston rings, cylinder and piston

⁽³⁾

Incorrect valve timing

⁽¹⁾

Improper engine oil (low viscosity)

⁽²⁾

Lubrication system

Incorrect oil pressure

⁽²⁾

Cooling system

Over-heating

⁽³⁾

Over-cooling

⁽³⁾

Other

Evaporative emission control system malfunction

⁽¹⁾

4. Surging

Engine control system < Ref. to BASIC DIAGNOSTIC PROCEDURE . >

⁽¹⁾

Intake system

Loosened or cracked intake duct

⁽¹⁾

Loosened or cracked PCV hose

⁽¹⁾

Loosened or cracked vacuum hose

⁽¹⁾

Defective intake manifold gasket

⁽²⁾

Defective throttle body gasket

⁽²⁾

Defective PCV valve

⁽²⁾

Loosened oil filler cap

⁽²⁾

Dirty air cleaner element

⁽²⁾

Fuel line

Defective fuel pump and relay

⁽²⁾

Clogged fuel line

⁽²⁾

Lack of or insufficient fuel

⁽³⁾

Belt

Defective timing

⁽²⁾

Compression

Incorrect valve clearance

⁽²⁾

Loosened spark plug or defective gasket

⁽³⁾

Loosened cylinder head bolt or defective gasket

⁽³⁾

Improper valve sealing

⁽³⁾

Defective valve stem

⁽³⁾

Worn or broken valve spring

⁽³⁾

Worn or stuck piston rings, cylinder and piston

⁽³⁾

Incorrect valve timing

⁽¹⁾

Improper engine oil (low viscosity)

⁽²⁾

Cooling system

Over-heating

⁽²⁾

Other

Evaporative emission control system malfunction

⁽³⁾

5. Engine does not return to idle.

Engine control system < Ref. to BASIC DIAGNOSTIC PROCEDURE . >

⁽¹⁾

Intake system

Loosened or cracked vacuum hose

⁽¹⁾

Other

Stuck or damaged throttle valve

⁽¹⁾

6. Dieseling (Run-on)

Engine control system < Ref. to BASIC DIAGNOSTIC PROCEDURE . >

⁽¹⁾

Cooling system

Over-heating

⁽²⁾

Other

Evaporative emission control system malfunction

⁽²⁾

7. After burning in exhaust system

Engine control system < Ref. to BASIC DIAGNOSTIC PROCEDURE . >

⁽¹⁾

Intake system

Loosened or cracked intake duct

⁽³⁾

Loosened or cracked PCV hose

⁽³⁾

Loosened or cracked vacuum hose

⁽²⁾

Defective PCV valve

⁽²⁾

Loosened oil filler cap

⁽³⁾

Belt

Defective timing

⁽²⁾

Compression

Incorrect valve clearance

⁽²⁾

Loosened spark plug or defective gasket

⁽³⁾

Loosened cylinder head bolt or defective gasket

⁽³⁾

Improper valve sealing

⁽²⁾

Defective valve stem

⁽³⁾

Worn or broken valve spring

⁽³⁾

Worn or stuck piston rings, cylinder and piston

⁽³⁾

Incorrect valve timing

⁽¹⁾

Lubrication system

Incorrect oil pressure

⁽³⁾

Cooling system

Over-cooling

⁽³⁾

Other

Evaporative emission control system malfunction

⁽³⁾

8. Knocking

Engine control system < Ref. to BASIC DIAGNOSTIC PROCEDURE . >

⁽¹⁾

Intake system

Loosened oil filler cap

⁽²⁾

Belt

Defective timing

⁽²⁾

Compression

Incorrect valve clearance

⁽³⁾

Incorrect valve timing

⁽²⁾

Cooling system

Over-heating

⁽¹⁾

9. Excessive engine oil consumption

Intake system

Loosened or cracked PCV hose

⁽¹⁾

Defective PCV valve

⁽²⁾

Loosened oil filler cap

⁽³⁾

Compression

Defective valve stem

⁽¹⁾

Worn or stuck piston rings, cylinder and piston

⁽¹⁾

Lubrication system

Loosened oil pump attaching bolts and defective gasket

⁽²⁾

Defective oil filter seal

⁽²⁾

Defective crankshaft oil seal

⁽²⁾

Defective rocker cover gasket

⁽²⁾

Loosened oil drain plug or defective gasket

⁽²⁾

Loosened oil pan fitting bolts or defective oil pan

⁽²⁾

10. Excessive fuel consumption

Engine control system < Ref. to BASIC DIAGNOSTIC PROCEDURE . >

⁽¹⁾

Intake system

Dirty air cleaner element

⁽¹⁾

Belt

Defective timing

⁽²⁾

Compression

Incorrect valve clearance

⁽²⁾

Loosened spark plug or defective gasket

⁽³⁾

Loosened cylinder head bolt or defective gasket

⁽³⁾

Improper valve sealing

⁽²⁾

Defective valve stem

⁽³⁾

Worn or broken valve spring

⁽³⁾

Worn or stuck piston rings, cylinder and piston

⁽²⁾

Incorrect valve timing

⁽²⁾

Lubrication system

Incorrect oil pressure

⁽³⁾

Cooling system

Over-cooling

⁽³⁾

⁽¹⁾	Very often

⁽²⁾

Sometimes

⁽³⁾

Rarely

RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.