Honda Civic manuals

Subaru Legacy Service Manual: Engine trouble in general inspection

Subaru Legacy Service Manual / Mechanical(h6do) / Engine trouble in general inspection

NOTE:

The “RANK” shown in the chart shows the possibilities of the cause of trouble in order from “Very often” to “Rarely”.

A — Very often

B — Sometimes

C — Rarely

Symptoms

Problem parts etc.

Possible cause

RANK

1. Engine does not start.

1) Starter does not turn.

Starter

Defective battery-to-starter harness

B

Defective starter switch

C

Defective relay

C

Defective inhibitor switch

C

Defective starter

B

Battery

Improper connection of terminal

A

Run-down battery

A

Defective charging system

B

Friction

Seizure of crankshaft and connecting rod bearing

C

Seized camshaft

C

Seized or stuck piston and cylinder

C

2) Initial combustion does not occur.

Starter

Defective starter

C

Engine control system Basic Diagnostic Procedure

A

Fuel line

Defective fuel pump and relay

A

Clogged fuel line

C

Lack of fuel or insufficient fuel

B

Timing chain

Trouble

B

Defective timing

B

Compression

Incorrect valve clearance

C

Loosened spark plug or defective gasket

C

Loosened cylinder head bolt or defective gasket

C

Improper valve sealing

C

Defective valve stem

C

Worn or broken valve spring

B

Worn or stuck piston rings, cylinder and piston

C

Incorrect valve timing

B

Improper engine oil (low viscosity)

B

3) Initial combustion occurs.

Engine control system Basic Diagnostic Procedure

A

Intake system

Defective intake manifold gasket

B

Defective throttle body gasket

B

Fuel line

Defective fuel pump and relay

C

Clogged fuel line

C

Lack of fuel or insufficient fuel

B

Timing chain

Trouble

B

Defective timing

B

Compression

Incorrect valve clearance

C

Loosened spark plug or defective gasket

C

Loosened cylinder head bolt or defective gasket

C

Improper valve sealing

C

Defective valve stem

C

Worn or broken valve spring

B

Worn or stuck piston rings, cylinder and piston

C

Incorrect valve timing

B

Improper engine oil (low viscosity)

B

4) Engine stalls after initial combustion.

Engine control system Basic Diagnostic Procedure

A

Intake system

Loosened or cracked intake duct

B

Loosened or cracked PCV hose

C

Loosened or cracked vacuum hose

C

Defective intake manifold gasket

B

Defective throttle body gasket

B

Dirty air cleaner element

C

Fuel line

Clogged fuel line

C

Lack of fuel or insufficient fuel

B

Timing chain

Trouble

B

Defective timing

B

Compression

Incorrect valve clearance

C

Loosened spark plug or defective gasket

C

Loosened cylinder head bolt or defective gasket

C

Improper valve sealing

C

Defective valve stem

C

Worn or broken valve spring

B

Worn or stuck piston rings, cylinder and piston

C

Incorrect valve timing

B

Improper engine oil (low viscosity)

B

2. Rough idle and engine stall

Engine control system Basic Diagnostic Procedure

A

Intake system

Loosened or cracked intake duct

A

Loosened or cracked PCV hose

A

Loosened or cracked vacuum hose

A

Defective intake manifold gasket

B

Defective throttle body gasket

B

Defective PCV valve

C

Loosened oil filler cap

B

Dirty air cleaner element

C

Fuel line

Defective fuel pump and relay

C

Clogged fuel line

C

Lack of fuel or insufficient fuel

B

Timing chain

Defective timing

C

Compression

Incorrect valve clearance

B

Loosened spark plug or defective gasket

B

Loosened cylinder head bolt or defective gasket

B

Improper valve sealing

B

Defective valve stem

C

Worn or broken valve spring

B

Worn or stuck piston rings, cylinder and piston

B

Incorrect valve timing

A

Improper engine oil (low viscosity)

B

Lubrication system

Incorrect oil pressure

B

Defective rocker cover gasket

C

Cooling system

Over-heating

C

Other

Evaporative emission control system malfunction

A

Stuck or damaged throttle valve

B

3. Low output, hesitation and poor acceleration

Engine control system Basic Diagnostic Procedure

A

Intake system

Loosened or cracked intake duct

A

Loosened or cracked PCV hose

A

Loosened or cracked vacuum hose

B

Defective intake manifold gasket

B

Defective throttle body gasket

B

Defective PCV valve

B

Loosened oil filler cap

B

Dirty air cleaner element

A

Fuel line

Defective fuel pump and relay

B

Clogged fuel line

B

Lack of fuel or insufficient fuel

C

Timing chain

Defective timing

B

Compression

Incorrect valve clearance

B

Loosened spark plug or defective gasket

B

Loosened cylinder head bolt or defective gasket

B

Improper valve sealing

B

Defective valve stem

C

Worn or broken valve spring

B

Worn or stuck piston rings, cylinder and piston

C

Incorrect valve timing

A

Improper engine oil (low viscosity)

B

Lubrication system

Incorrect oil pressure

B

Defective rocker cover gasket

C

Cooling system

Over-heating

C

Over-cooling

C

Other

Evaporative emission control system malfunction

A

4. Surging

Engine control system Basic Diagnostic Procedure

A

Intake system

Loosened or cracked intake duct

A

Loosened or cracked PCV hose

A

Loosened or cracked vacuum hose

A

Defective intake manifold gasket

B

Defective throttle body gasket

B

Defective PCV valve

B

Loosened oil filler cap

B

Dirty air cleaner element

B

Fuel line

Defective fuel pump and relay

B

Clogged fuel line

B

Lack of fuel or insufficient fuel

C

Timing chain

Defective timing

B

Compression

Incorrect valve clearance

B

Loosened spark plug or defective gasket

C

Loosened cylinder head bolt or defective gasket

C

Improper valve sealing

C

Defective valve stem

C

Worn or broken valve spring

C

Worn or stuck piston rings, cylinder and piston

C

Incorrect valve timing

A

Improper engine oil (low viscosity)

B

Cooling system

Over-heating

B

Other

Evaporative emission control system malfunction

C

5. Engine does not return to idle.

Engine control system Basic Diagnostic Procedure

A

Intake system

Loosened or cracked vacuum hose

A

Other

Stuck or damaged throttle valve

A

6. Dieseling (run-on)

Engine control system Basic Diagnostic Procedure

A

Cooling system

Over-heating

B

Other

Evaporative emission control system malfunction

B

7. After burning in exhaust system

Engine control system Basic Diagnostic Procedure

A

Intake system

Loosened or cracked intake duct

C

Loosened or cracked PCV hose

C

Loosened or cracked vacuum hose

B

Defective PCV valve

B

Loosened oil filler cap

C

Timing chain

Defective timing

B

Compression

Incorrect valve clearance

B

Loosened spark plug or defective gasket

C

Loosened cylinder head bolt or defective gasket

C

Improper valve sealing

B

Defective valve stem

C

Worn or broken valve spring

C

Worn or stuck piston rings, cylinder and piston

C

Incorrect valve timing

A

Lubrication system

Incorrect oil pressure

C

Cooling system

Over-cooling

C

Other

Evaporative emission control system malfunction

C

8. Knocking

Engine control system Basic Diagnostic Procedure

A

Intake system

Loosened oil filler cap

B

Timing chain

Defective timing

B

Compression

Incorrect valve clearance

C

Incorrect valve timing

B

Cooling system

Over-heating

A

9. Excessive engine oil consumption

Intake system

Loosened or cracked PCV hose

A

Defective PCV valve

B

Loosened oil filler cap

C

Compression

Defective valve stem

A

Worn or stuck piston rings, cylinder and piston

A

Lubrication system

Loosened oil pump attaching bolts and defective gasket

B

Defective oil filter O-ring

B

Defective crankshaft oil seal

B

Defective rocker cover gasket

B

Loosened oil drain plug or defective gasket

B

Loosened oil pan fitting bolts or defective oil pan

B

10. Excessive fuel consumption

Engine control system Basic Diagnostic Procedure

A

Intake system

Dirty air cleaner element

A

Timing chain

Defective timing

B

Compression

Incorrect valve clearance

B

Loosened spark plug or defective gasket

C

Loosened cylinder head bolt or defective gasket

C

Improper valve sealing

B

Defective valve stem

C

Worn or broken valve spring

C

Worn or stuck piston rings, cylinder and piston

B

Incorrect valve timing

B

Lubrication system

Incorrect oil pressure

C

Cooling system

Over-cooling

C

Engine oil pressure inspection
1. Disconnect the ground terminal from battery sensor. NOTE2. Remove the oil pressure switch from the oil pan upper. Oil Pressure Switch > REMOVAL3. Attach the oil pressure gauge to the oil pan uppe ...

Fuel pressure inspection
1. Remove the collector cover.(1) Carefully pull up the rear of collector cover at two positions (A).(2) Carefully pull up the front of collector cover at two positions (B) while moving it forward.2. ...

Other materials:

Front seat heater (if equipped)
Front seat heater switch  HIGH mode indicator  MID mode indicator  LOW mode indicator  Driver's side  Front passenger's side Press the front seat heater switch. Each time you press the switch, the mode will change as follows. When LOW mode is select ...

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