Engine Trouble In General - Subaru 2002 IMPREZA Service Manual

Starter Defective battery-to-starter harness
Defective starter switch
Defective inhibitor switch or neutral switch
B
C
C
Run-down battery
Defective charging system
Seizure of crankshaft and connecting rod bearing
Seized camshaft
A
B
C
C
Loosened cylinder head bolts or defective gasket
Improper valve seating
Defective valve stem
C
C
C
I
Improper engine oil (low viscosity)
Engine control system <Ref. to EN(D0HC TURBO)-2, Basic Diagnostic Procedure.>
Intake system Defective intake manifold gasket
Defective throttle bodv aasket
B
A
B
B
Compression
"
Incorrect valve clearance C
Loosened spark plugs or defective gasket C
Loosened cylinder head bolts or defective gasket C
Defective valve stem
Worn or broken valve spring
Worn or stuck piston rinas. cvlinder and piston
C
B
C
ENGINE TROUBLE IN GENERAL
MECHANICAL
21 .Engine Trouble in General
A: INSPECTION
NOTE: A - Very often
"RANK' shown in the chart refers to the possibility
of reason for the trouble in order ("Very often" to
"Rarely")
B
-
Sometimes
C
-
Rarely
PROBLEM PARTS, ETC.
I
POSSIBLE CAUSE
I
RANK
TROUBLE
1. Engine will not start.
1) Starter does not turn.
1
Defective starter I B
I
Poor terminal connection
I A
Battery
Friction
I
Seized or stuck piston and cylinder
I C
~~
2) Initial combustion does
not occur.
Starter
1
Defective starter I C
Engine control system <Ref. to EN(D0HC TURBO)-2, Basic Diagnostic Procedure.>
1
A
Fuel line Defective fuel pump and relay
Lack of or insufficient fuel
I A
I B
I
I
Belt
I
Defective I B
I
Defective timina I B
Compression
I
Incorrect valve clearance
I C
1
Loosened spark plugs or defective gasket
I C
F W o r n G broken valve sprina I B
I
Worn or stuck piston rings, cylinder and piston
I C
I
Incorrect valve timing
I B
3) Initial combustion occur.
~~
Fuel line
I
Defective fuel pump and relay
I C
1
Clogged fuel line
I C
I
Lack of or insufficient fuel
I B
Belt
Defective I B
Defective timina I B
I
Improper valve seating
I C
I.lncorrect v a G timina I B
I
Improper engine oil (low viscosity)
I B
ME(D0HC TURBO)-91