Subaru Legacy 2004 Service Manual page 316

MECHANICAL
Symptom
5. Engine does not return to
idle.
6. Dieseling (Run-on)
7. After burning in exhaust
system
8. Knocking
9. Excessive engine oil con-
sumption
Engine Trouble in General
Problem parts, etc.
Engine control system <Ref. to EN(H4SO 2.0)(diag)-2, Basic Diagnostic Procedure.>
Intake system
Other
Engine control system <Ref. to EN(H4SO 2.0)(diag)-2, Basic Diagnostic Procedure.>
Cooling system
Other
Engine control system <Ref. to EN(H4SO 2.0)(diag)-2, Basic Diagnostic Procedure.>
Intake system
Belt
Compression
Lubrication system
Cooling system
Other
Engine control system <Ref. to EN(H4SO 2.0)(diag)-2, Basic Diagnostic Procedure.>
Intake system
Belt
Compression
Cooling system
Intake system
Compression
Lubrication system
ME(H4SO 2.0)-86
Possible cause
Loosened or cracked vacuum hose
Stuck or damaged throttle valve
Over-heating
Evaporative emission control system malfunction
Loosened or cracked intake duct
Loosened or cracked PCV hose
Loosened or cracked vacuum hose
Defective PCV valve
Loosened oil filler cap
Defective timing
Incorrect valve clearance
Loosened spark plug or defective gasket
Loosened cylinder head bolt or defective gasket
Improper valve sealing
Defective valve stem
Worn or broken valve spring
Worn or stuck piston rings, cylinder and piston
Incorrect valve timing
Incorrect oil pressure
Over-cooling
Evaporative emission control system malfunction
Loosened oil filler cap
Defective timing
Incorrect valve clearance
Incorrect valve timing
Over-heating
Loosened or cracked PCV hose
Defective PCV valve
Loosened oil filler cap
Defective valve stem
Worn or stuck piston rings, cylinder and piston
Loosened oil pump attaching bolts and defective gas-
ket
Defective oil filter seal
Defective crankshaft oil seal
Defective rocker cover gasket
Loosened oil drain plug or defective gasket
Loosened oil pan fitting bolts or defective oil pan
RANK
A
A
A
A
B
B
A
C
C
B
B
C
B
B
C
C
B
C
C
C
A
C
C
C
A
B
B
C
B
A
A
B
C
A
A
B
B
B
B
B
B