Subaru Impreza 2003 Service Manual page 307

TROUBLE
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, Basic Diagnostic Procedure.> or <Ref. to
EN(H4SOw/oOBD)-2, Basic Diagnostic Procedure.>
• Intake system
• Others
• Engine control system <Ref. to EN(H4SO)-2, Basic Diagnostic Procedure.> or <Ref. to
EN(H4SOw/oOBD)-2, Basic Diagnostic Procedure.>
• Cooling system
• Others
• Engine control system <Ref. to EN(H4SO)-2, Basic Diagnostic Procedure.> or <Ref. to
EN(H4SOw/oOBD)-2, Basic Diagnostic Procedure.>
• Intake system
• Belt
• Compression
• Lubrication system
• Cooling system
• Others
• Engine control system <Ref. to EN(H4SO)-2, Basic Diagnostic Procedure.> or <Ref. to
EN(H4SOw/oOBD)-2, Basic Diagnostic Procedure.>
• Intake system
• Belt
• Compression
• Cooling system
• Intake system
• Compression
• Lubrication system
ME(H4SO)-95
POSSIBLE CAUSE
• Loosened or cracked vacuum hose
• Stuck or damaged throttle valve
• Accelerator cable out of adjustment
• Overheating
• Malfunction of evaporative emission control system
• 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 plugs or defective gasket
• Loosened cylinder head bolts or defective gasket
• Improper valve seating
• Defective valve stem
• Worn or broken valve spring
• Worn or stuck piston rings, cylinder and piston
• Incorrect valve timing
• Incorrect oil pressure
• Over cooling
• Malfunction of evaporative emission control system
• Loosened oil filler cap
• Defective timing
• Incorrect valve clearance
• Incorrect valve timing
• Overheating
• 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
gasket
• 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
MECHANICAL
RANK
A
A
A
B
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