2004 SUBARU FORESTER spark plugs

ME(H4SO)-26
MECHANICAL
Idle Speed
3. Idle Speed
A: INSPECTION
1) Before checking idle speed, check the following:
(1) Ensure the air cleaner element is free from
clogging, ignition timing is correct, spark plugs
are in good condition, and the hoses are con-
nected properly.
(2) Ensure the malfunction indicator light does
not illuminate.
2) Warm-up the engine.
3) Stop the engine, and then turn the ignition switch
to OFF.
4) When using the Subaru Select Monitor, refer to
the following. TOOL, PREPARATION TOOL, General Descrip-
tion.>
(1) Insert the cartridge to Subaru Select Moni-
tor.
(2) Connect the Subaru Select Monitor to data
link connector.
(3) Turn the ignition switch to ON, and Subaru
Select Monitor switch to ON.
(4) Select the {Each System Check} in Main
Menu.
(5) Select the {Engine Control System} in Se-
lection Menu.
(6) Select the {Current Data Display & Save} in
Engine Control System Diagnosis.
(7) Select the {Data Display} in Data Display
Menu.
(8) Start the engine, and then read the engine
idle speed.
5) When using the tachometer (Secondary pick-up
type).
(1) Attach the pick-up clip to No. 1 cylinder
spark plug cord.(2) Start the engine, and then read the engine
idle speed.
NOTE:
 When using the OBD-II general scan tool, care-
fully read its operation manual.
 This ignition system provides simultaneous igni-
tion for #1 and #2 plugs. It must be noted that some
tachometers may register twice that of actual en-
gine speed.
6) Check the idle speed when unloaded. (With
headlights, heater fan, rear defroster, radiator fan,
air conditioning, etc. OFF)
Idle speed [No load and gears in “N” or “P”
range]:
650
±100 rpm
7) Check the idle speed when loaded. (Turn the air
conditioning switch to “ON” and operate the com-
pressor for at least 1 minute before measurement.)
Idle speed [A/C “ON”, no load and gears in “N”
or “P” range]:
850
±100 rpm
NOTE:
Idle speed can not be adjusted manually, because
the idle speed is automatically adjusted.
If the specified idle speed can not be maintained,
refer to General On-board Diagnosis Table under
“Engine Control System”. Basic Diagnostics Procedure.>
ME-00325
ME-00193

ME(H4SO)-31
MECHANICAL
Valve Clearance
8. Valve Clearance
A: INSPECTION
NOTE:
Inspection and adjustment of the valve clearance
should be performed while engine is cold.
1) Set the vehicle on a lift.
2) Lift-up the vehicle.
3) Remove the under cover.
4) Lower the vehicle.
5) Disconnect the ground cable from battery.
6) Remove the belt cover (LH).
7) When inspecting the #1 and #3 cylinders:
(1) Disconnect the spark plug cords from spark
plugs RH side. REMOVAL, Spark Plug.>
(2) Disconnect the PCV hose from rocker cover
(RH).
(3) Remove the bolts, and then remove the
rocker cover (RH).
8) When inspecting the #2 and #4 cylinders:
(1) Disconnect the spark plug cords from spark
plugs (LH Side) REMOVAL, Spark Plug.>
(2) Disconnect the PCV hose from rocker cover
(LH).
(3) Remove the bolts, and then remove the
rocker cover (LH).
9) Set the #1 cylinder piston to top dead center of
compression stroke by rotating crank pulley clock-
wise using a socket wrench.NOTE:
When arrow mark (A) on the cam sprocket (LH)
comes exactly to the top, #1 cylinder piston is
brought to the top dead center of compression
stroke.
10) Measure the #1 cylinder valve clearance by us-
ing thickness gauge.
CAUTION:
 Insert the thickness gauge (A) in as horizon-
tal a direction as possible with respect to the
valve stem end face.
 Measure the exhaust valve clearances while
lifting-up the vehicle.
Valve clearance (Standard):
Intake;
0.20
±0.04 mm (0.0079±0.0016 in)
Exhaust;
0.25
±0.04 mm (0.0098±0.0016 in)
11) If necessary, adjust the valve clearance. to ME(H4SO)-32, ADJUSTMENT, Valve Clear-
ance.>
12) Similar to measurement procedures used for
#1 cylinder, measure the #2, #3 and #4 cylinder
valve clearances.
NOTE:
 Be sure to set the cylinder pistons to their re-
spective top dead centers on compression stroke
before measuring valve clearances.
FU-00009
ME-00199
ME-00200
(A)
ME-00201
(A)

ME(H4SO)-91
MECHANICAL
Engine Trouble in General
22.Engine Trouble in General
A: INSPECTION
NOTE:
“RANK” shown in the chart refer to the possibility of reason for the trouble in order (“Very often” to “Rarely”)
A — Very often
B — Sometimes
C — Rarely
TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK
1. Engine will 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 Poor terminal connection A
Run-down battery A
Defective charging system B
Friction Seizure of crankshaft and connecting rod bearing 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
Belt Defective B
Defective timing B
Compression Incorrect valve clearance C
Loosened spark plugs or defective gasket C
Loosened cylinder head bolts or defective gasket C
Improper valve seating C
Defective valve stem C
Worn or broken valve spring B
Worn or stuck piston rings, cylinder and piston C
Incorrect valve timing B
Improper engine oil (low viscosity) B
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
Belt Defective B
Defective timing B
Compression Incorrect valve clearance C
Loosened spark plugs or defective gasket C
Loosened cylinder head bolts or defective gasket C
Improper valve seating C
Defective valve stem C
Worn or broken valve spring B
Worn or stuck piston rings, cylinder and piston C
Incorrect valve timing B
Improper engine oil (low viscosity) B

ME(H4SO)-92
MECHANICAL
Engine Trouble in General
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
Belt Defective B
Defective timing B
Compression Incorrect valve clearance C
Loosened spark plugs or defective gasket C
Loosened cylinder head bolts or defective gasket C
Improper valve seating C
Defective valve stem C
Worn or broken valve spring B
Worn or stuck piston rings, cylinder and piston C
Incorrect valve timing B
Improper engine oil (low viscosity) B
2. Rough idle and engine
stallEngine 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
Belt Defective timing C
Compression Incorrect valve clearance B
Loosened spark plugs or defective gasket B
Loosened cylinder head bolts or defective gasket B
Improper valve seating B
Defective valve stem C
Worn or broken valve spring B
Worn or stuck piston rings, cylinder and piston B
Incorrect valve timing A
Improper engine oil (low viscosity) B
Lubrication system Incorrect oil pressure B
Defective rocker cover gasket C
Cooling system Overheating C
Others Malfunction of evaporative emission control system A
Stuck or damaged throttle valve B
Accelerator cable out of adjustment C TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK

ME(H4SO)-93
MECHANICAL
Engine Trouble in General
3. Low output, hesitation and
poor accelerationEngine 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
Belt Defective timing B
Compression Incorrect valve clearance B
Loosened spark plugs or defective gasket B
Loosened cylinder head bolts or defective gasket B
Improper valve seating B
Defective valve stem C
Worn or broken valve spring B
Worn or stuck piston rings, cylinder and piston C
Incorrect valve timing A
Improper engine oil (low viscosity) B
Lubrication system Incorrect oil pressure B
Cooling system Overheating C
Over cooling C
Others Malfunction of evaporative emission control system A
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
Belt Defective timing B
Compression Incorrect valve clearance B
Loosened spark plugs or defective gasket C
Loosened cylinder head bolts or defective gasket C
Improper valve seating C
Defective valve stem C
Worn or broken valve spring C
Worn or stuck piston rings, cylinder and piston C
Incorrect valve timing A
Improper engine oil (low viscosity) B
Cooling system Overheating B
Others Malfunction of evaporative emission control system C TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK

ME(H4SO)-94
MECHANICAL
Engine Trouble in General
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
Accelerator cable out of adjustment B
6. Dieseling (Run-on) Engine control system A
Cooling system Overheating B
Others Malfunction of evaporative emission control system B
7. After burning in exhaust
systemEngine 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
Belt Defective timing B
Compression Incorrect valve clearance B
Loosened spark plugs or defective gasket C
Loosened cylinder head bolts or defective gasket C
Improper valve seating B
Defective valve stem C
Worn or broken valve spring C
Worn or stuck piston rings, cylinder and piston C
Incorrect valve timing A
Lubrication system Incorrect oil pressure C
Cooling system Over cooling C
Others Malfunction of evaporative emission control system C
8. Knocking Engine control system A
Intake system Loosened oil filler cap B
Belt Defective timing B
Compression Incorrect valve clearance C
Incorrect valve timing B
Cooling system Overheating A
9. Excessive engine oil con-
sumptionIntake system Loosened or cracked PCV hose A
Defective PCV valve B
Loosened oil filler cap C
Compression Defective valve stem A
Worn or stuck piston rings, cylinder and piston A
Lubrication system Loosened oil pump attaching bolts and defective gas-
ketB
Defective oil filter seal 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 TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK

ME(H4SO)-95
MECHANICAL
Engine Trouble in General
10. Excessive fuel consump-
tionEngine control system A
Intake system Dirty air cleaner element A
Belt Defective timing B
Compression Incorrect valve clearance B
Loosened spark plugs or defective gasket C
Loosened cylinder head bolts or defective gasket C
Improper valve seating B
Defective valve stem C
Worn or broken valve spring C
Worn or stuck piston rings, cylinder and piston B
Incorrect valve timing B
Lubrication system Incorrect oil pressure C
Cooling system Over cooling C
Others Accelerator cable out of adjustment B TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK

IG(H4SO)-5
IGNITION
Spark Plug
2. Spark Plug
A: REMOVAL
CAUTION:
All spark plugs installed on an engine, must be
of the same heat range.
1. RH SIDE
1) Disconnect the ground cable from battery.
2) Remove the air cleaner case. 8, REMOVAL, Resonator Chamber.>
3) Remove the spark plug cords by pulling boot, not
the cord itself.
4) Remove the spark plugs with spark plug sock-
ets.
2. LH SIDE
1) Disconnect the ground cable from battery.
2) Disconnect the washer motor connector.
3) Disconnect the rear window glass washer hose
from washer motor, then plug connection with a
suitable cap.
4) Remove the two bolts which hold washer tank,
then take the tank away from the working area.
5) Remove the spark plugs cord by pulling boot, not
the cord itself.
Spark plug
CHAMPION: RC10YC4
NGK: BKR5E-11 (Alternate)
FU-00009
IG-00017
IG-00018
FU-00009
IG-00019
IG-00020
IG-00021