2009 SUBARU TRIBECA Spark plug

ME(H6DO)-83
Engine Trouble in General
MECHANICAL
28.Engine Trouble in General
A: INSPECTION
NOTE:
The “RANK” shown in the chart shows the possibilities of the cause of trouble in order from “most likely” to
“rarely”.
A — Most likely
B — Sometimes
C — Rarely
Symptom 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 inhibitor switch or neutral switch C
Defective starter B
Battery Improper connection of terminal A
Run-down battery A
Defective charging system B
Fr iction Seizure of crankshaft and connecting rod bear ing C
Seized camshaft C
Seized or stuck piston and cylinder C
2) Initial combustion does
not occur.
Starter Defective starter C
Engine control system A
Fuel line Defective fuel pump and relay A
Lack of or insufficient fuel B
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
Wor n or broken valve spr ing B
Wor n or stuck piston r ings, cylinder and piston C
Incorrect valve timing B
Improper engine oil (low viscosity) B
Tr o u b l e o f t a p p e t C
Tr o u b l e o f t a p p e t . I n c a s e n o i s e o c c u r s w i t h v a l v e m o v -
ing. Or the harness involved to oil switching solenoid
valve, variable valve lift diagnosis oil pressure switch
and variable valve lift has trouble in a past.
B

ME(H6DO)-84
Engine Trouble in General
MECHANICAL
3) Initial combustion occurs. Engine control system 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 or insufficient fuel B
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
Wor n or broken valve spr ing B
Wor n or stuck piston r ings, cylinder and piston C
Incorrect valve timing B
Improper engine oil (low viscosity) B
Tr o u b l e o f t a p p e t C
Tr o u b l e o f t a p p e t . I n c a s e n o i s e o c c u r s w i t h v a l v e m o v -
ing. Or the harness involved to oil switching solenoid
valve, variable valve lift diagnosis oil pressure switch
and variable valve lift has trouble in a past.
B
4) Engine stalls after initial
combustion.
Engine control system 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 or insufficient fuel B
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
Wor n or broken valve spr ing B
Wor n or stuck piston r ings, cylinder and piston C
Incorrect valve timing B
Improper engine oil (low viscosity) B
Tr o u b l e o f t a p p e t C
Tr o u b l e o f t a p p e t . I n c a s e n o i s e o c c u r s w i t h v a l v e m o v -
ing. Or the harness involved to oil switching solenoid
valve, variable valve lift diagnosis oil pressure switch
and variable valve lift has trouble in a past.
B
Symptom Problem parts etc. Possible cause RANK

ME(H6DO)-85
Engine Trouble in General
MECHANICAL
2. Rough idle and engine
stall
Engine control system 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 or insufficient fuel B
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
Wor n or broken valve spr ing B
Wor n or stuck piston r ings, cylinder and piston B
Incorrect valve timing A
Improper engine oil (low viscosity) B
Tr o u b l e o f t a p p e t C
Tr o u b l e o f t a p p e t . I n c a s e n o i s e o c c u r s w i t h v a l v e m o v -
ing. Or the harness involved to oil switching solenoid
valve, variable valve lift diagnosis oil pressure switch
and variable valve lift has trouble in a past.
B
Lubrication system Incorrect oil pressure B
Defective rocker cover gasket C
Cooling system Over-heating C
Others Evaporative emission control system malfunction A
Stuck or damaged throttle valve B
Symptom Problem parts etc. Possible cause RANK

ME(H6DO)-86
Engine Trouble in General
MECHANICAL
3. Low output, hesitation and
poor acceleration
Engine control system 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 or insufficient fuel C
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
Wor n or broken valve spr ing B
Wor n or stuck piston r ings, cylinder and piston C
Incorrect valve timing A
Improper engine oil (low viscosity) B
Tr o u b l e o f t a p p e t C
Tr o u b l e o f t a p p e t . I n c a s e n o i s e o c c u r s w i t h v a l v e m o v -
ing. Or the harness involved to oil switching solenoid
valve, variable valve lift diagnosis oil pressure switch
and variable valve lift has trouble in a past.
B
Lubrication system Incorrect oil pressure B
Cooling system Over-heating C
Over-cooling C
Others Evaporative emission control system malfunction A
Symptom Problem parts etc. Possible cause RANK

ME(H6DO)-87
Engine Trouble in General
MECHANICAL
4. Surging Engine control system 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 or insufficient fuel C
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
Wor n or broken valve spr ing C
Wor n or stuck piston r ings, cylinder and piston C
Incorrect valve timing A
Improper engine oil (low viscosity) B
Tr o u b l e o f t a p p e t C
Tr o u b l e o f t a p p e t . I n c a s e n o i s e o c c u r s w i t h v a l v e m o v -
ing. Or the harness involved to oil switching solenoid
valve, variable valve lift diagnosis oil pressure switch
and variable valve lift has trouble in a past.
B
Cooling system Over-heating B
Others Evaporative emission control system malfunction C
5. Engine does not return to
idle.
Engine control system A
Intake system Loosened or cracked vacuum hose A
Others Stuck or damaged throttle valve A
6. Dieseling (Run-on) Engine control system A
Cooling system Over-heating B
Others Evaporative emission control system malfunction B
Symptom Problem parts etc. Possible cause RANK

ME(H6DO)-88
Engine Trouble in General
MECHANICAL
7. After burning in exhaust
system
Engine control system 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
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
Wor n or broken valve spr ing C
Wor n or stuck piston r ings, cylinder and piston C
Incorrect valve timing A
Tr o u b l e o f t a p p e t C
Tr o u b l e o f t a p p e t . I n c a s e n o i s e o c c u r s w i t h v a l v e m o v -
ing. Or the harness involved to oil switching solenoid
valve, variable valve lift diagnosis oil pressure switch
and variable valve lift has trouble in a past.
B
Lubrication system Incorrect oil pressure C
Cooling system Over-cooling C
Others Evaporative emission control system malfunction C
8. Knocking Engine control system A
Intake system Loosened oil filler cap B
Chain Defective timing B
Compression Incorrect valve clearance C
Incorrect valve timing B
Tr o u b l e o f t a p p e t C
Tr o u b l e o f t a p p e t . I n c a s e n o i s e o c c u r s w i t h v a l v e m o v -
ing. Or the harness involved to oil switching solenoid
valve, variable valve lift diagnosis oil pressure switch
and variable valve lift has trouble in a past.
B
Cooling system Over-heating A
9. Excessive engine oil con-
sumption
Intake system Loosened or cracked PCV hose A
Defective PCV valve B
Loosened oil filler cap C
Compression Defective valve stem A
Wor n or stuck piston r ings, cylinder and piston A
Lubrication system Loosened oil pump attaching bolts and defective gas-
ket
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
Symptom Problem parts etc. Possible cause RANK

ME(H6DO)-89
Engine Trouble in General
MECHANICAL
10. Excessive fuel consump-
tion
Engine control system A
Intake system Dirty air cleaner element A
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
Wor n or broken valve spr ing C
Wor n or stuck piston r ings, cylinder and piston B
Incorrect valve timing B
Tr o u b l e o f t a p p e t C
Tr o u b l e o f t a p p e t . I n c a s e n o i s e o c c u r s w i t h v a l v e m o v -
ing. Or the harness involved to oil switching solenoid
valve, variable valve lift diagnosis oil pressure switch
and variable valve lift has trouble in a past.
B
Lubrication system Incorrect oil pressure C
Cooling system Over-cooling C
Symptom Problem parts etc. Possible cause RANK

ME(H6DO)-90
Engine Noise
MECHANICAL
29.Engine Noise
A: INSPECTION
(NOTE*)
When disconnecting the fuel injector connector, the malfunction indicator light illuminates and DTC is stored in ECM memory.
Therefore, carry out the clear memory mode and inspection
mode after connecting the fuel injector connector.
Ty p e o f s o u n d C o n d i t i o n P o s s i b l e c a u s e
Regular clicking soundSound increases as engine
speed increases.
•Valve mechanism is defective.
•Incorrect valve clearance
•Worn valve rocker
•Worn camshaft
•Broken valve spring
•Trouble of tappet
Heavy and dull clankOil pressure is low.•Worn camshaft main bearing
•Worn connecting rod bearing (large end)
Oil pressure is normal. Damaged engine mounting
High-pitched clank
Sound is noticeable when
accelerating with an overload
condition.
•Ignition timing advanced
•Accumulation of carbon inside combustion chamber
•Wrong spark plug
•Improper gasoline
Clank when engine speed is
between 1,000 and 2,000
rpms.
Sound is reduced when fuel
injector connector of noisy cyl-
inder is disconnected.
(NOTE*)
•Worn crankshaft main bearing
•Worn bearing at crankshaft end of connecting rod
Knocking sound when engine
is operating under idling speed
and engine is warm
Sound is reduced when fuel
injector connector of noisy cyl-
inder is disconnected.
(NOTE*)
•Worn cylinder liner and piston ring
•Broken or stuck piston ring
•Worn piston pin and hole at piston end of connecting rod
Sound is not reduced if each
fuel injector connector is dis-
connected in turn. (NOTE*)
•Unusually worn valve lifter
•Worn cam gear
•Worn camshaft journal bore in crankcase
Squeaky sound — • Insufficient generator lubrication
Rubbing sound — • Poor contact of generator brush and rotor
Gear scream when starting
engine—•Defective ignition starter switch
•Worn gear and starter pinion
Sound like polishing glass with
a dry cloth—•Loose drive belt
•Defective water pump shaft
Hissing sound —•Insufficient compression
•Air leakage in air intake system, hose, connection or manifold
Timing belt noise —•Loose timing belt
•Belt contacting with case/adjacent part
Va l ve t a p p e t n o i s e —•Incorrect valve clearance
•Trouble of tappet