Subaru IMPREZA 2002 Service Manual page 191

Cooling system
Others
Overheating B
Malfunction of evaporative emission control system B
Enaine control svstem <Ref. to EN(SOHC)-2, Basic Diaanostic Procedure.>
A
I
Loosened or cracked vacuum hose
Defective PCV valve
Loosened oil filler cap
Defective timina
B
B
C
B
Improper valve seating
Defective valve stem
Worn or broken valve spring
Worn or stuck Diston rinas, cvlinder and Diston
B
C
C
C
Cooling system
Others
Over cooling C
Malfunction of evaporative emission control system C
Engine control system <Ref. to EN(SOHC)Q, Basic Diagnostic Procedure.>
Intake svstem
I
Loosened oil filler caD
A
B
Overheating
Loosened or cracked PCV hose
Defective PCV valve
A
A
B
Worn or stuck piston rings, cylinder and piston
Loosened oil pump attaching bolts and defective
gasket
Defective oil filter o-rina
A
B
B
Defective rocker cover gasket
Loosened oil drain plug or defective gasket
Loosened oil pan fitting bolts or defective oil pan
B
B
B
ENGINE TROUBLE IN GENERAL
MECHANICAL
PROBLEM PARTS, ETC.
[
POSSIBLE CAUSE
I
RANK
Enaine control svstem <Ref. to ENC3OHC)Q. Basic Diaanostic Procedure.>
I A
TROUBLE
5. Engine does not return to
idle.
.Intake svsxm
I
Loosened or cracked vacuum hose
] A I
\ A I
I
Stuck or damaned throttle valve
Others
I
Accelerator cable out of adjustment
I B
I A
Engine control system <Ref. to EN(SOHC)Q, Basic Diagnostic Procedure.> 6. Dieseling (Run-on)
7. After burning in exhaust
system
Intake system
I
Loosened or cracked intake duct
I C 1
I
Loosened or cracked PCV hose
I C 1
Belt
0
Compression
I
Incorrect valve clearance
1 B 1
I
Loosened spark plugs or defective gasket
I C 1
I
Loosened cylinder head bolts or defective gasket
I
C
I
I
Incorrect valve timing
I A I
Lubrication system
I
Incorrect oil pressure I C 1
8. Knocking
Belt
I
Defective timina 1 B 1
Compression
I
Incorrect valve clearance
I C 1
I
Incorrect valve timing
1 B 1
Cooling system
Intake system 9. Excessive engine oil con-
sumption
I
Loosened oil filler cap
I C 1
Compression
Defective valve stem I A I
Lubrication system
I
Defective crankshaft oil seal
1 B 1
M E( S0HC)-93