2004 SUBARU FORESTER check engine

EN(H4SO)-256
ENGINE (DIAGNOSTIC)
General Diagnostic Table
*1: Check ignition coil & ignitor ASSY and spark plug.
*2: Indicate the symptom occurring only in cold temperatures.
*3: Ensure the secure installation.
*4: Check fuel injector, fuel pressure regulator and fuel filter.
*5: Inspect air leak in air intake system.
*6: Adjust the accelerator cable.
2. AUTOMATIC TRANSMISSION
NOTE:
Check general diagnostics table with non-conformity symptom for automatic transmission. 4AT(H4SO)-2, Basic Diagnostic Procedure.>
6. Surging1) Intake manifold pressure sensor
2) Intake air temperature sensor
3) Manifold absolute pressure sensor
4) Engine coolant temperature sensor (*2)
5) Crankshaft position sensor (*3)
6) Camshaft position sensor (*3)
7) Fuel injection parts (*4)
8) Throttle position sensor
9) Fuel pump and fuel pump relay
7. Spark knock1) Intake manifold pressure sensor
2) Intake air temperature sensor
3) Manifold absolute pressure sensor
4) Engine coolant temperature sensor
5) Knock sensor
6) Fuel injection parts (*4)
7) Fuel pump and fuel pump relay
8. After burning in exhaust system1) Intake manifold pressure sensor
2) Intake air temperature sensor
3) Manifold absolute pressure sensor
4) Engine coolant temperature sensor (*2)
5) Fuel injection parts (*4)
6) Fuel pump and fuel pump relay Symptom Problem parts

IN(H4DOTC)-15
INTAKE (INDUCTION)
Resonator Chamber
8. Resonator Chamber
A: REMOVAL
1) Set the vehicle on a lift.
2) Remove the air intake duct. IN(H4DOTC)-8, REMOVAL, Air Intake Duct.>
3) Remove the air cleaner lower case. IN(H4DOTC)-7, REMOVAL, Air Cleaner.>
4) Remove the resonator chamber mounting bolt
on the right of engine compartment.
5) Remove the front right tire, and lift the vehicle.
6) Remove the front mudguard RH.
7) Remove the resonator chamber from the inside
front fender.
B: INSTALLATION
Install in the reverse order of removal.
Tightening torque:
7.5 N
⋅m (0.76 kgf-m, 5.5 ft-lb)
C: INSPECTION
Inspect for cracks and loose connections. Check
that no foreign objects are mixed in the resonator
chamber.
IN-00025
IN-00026
IN-00026
IN-00025

ME(H4DOTC)-22
MECHANICAL
General Description
C: CAUTION
 Wear working clothing, including a cap, protec-
tive goggles, and protective shoes during opera-
tion.
 Remove contamination including dirt and corro-
sion before removal, installation or disassembly.
 Keep the disassembled parts in order and pro-
tect them from dust or dirt.
 Before removal, installation or disassembly, be
sure to clarify the failure. Avoid unnecessary re-
moval, installation, disassembly, and replacement.
 Be careful not to burn yourself, because each
part in the vehicle is hot after running.
 Be sure to tighten fasteners including bolts and
nuts to the specified torque.
 Place shop jacks or rigid racks at the specified
points.
 Before disconnecting electrical connectors of
sensors or units, be sure to disconnect the ground
cable from battery.
 All parts should be thoroughly cleaned, paying
special attention to the engine oil passages, pis-
tons and bearings.
 Rotating parts and sliding parts such as piston,
bearing and gear should be coated with oil prior to
assembly.
 Be careful not to let oil, grease or coolant contact
the timing belt, clutch disc and flywheel.
 All removed parts, if to be reused, should be re-
installed in the original positions and directions.
 Bolts, nuts and washers should be replaced with
new ones as required.
 Even if necessary inspections have been made
in advance, proceed with assembly work while
making rechecks.
 Remove or install the engine in an area where
chain hoists, lifting devices, etc. are available for
ready use.
 Be sure not to damage coated surfaces of body
panels with tools or stain seats and windows with
coolant or oil. Place a cover over fenders, as re-
quired, for protection.
 Prior to starting work, prepare the following:
Service tools, clean cloth, containers to catch cool-
ant and oil, wire ropes, chain hoist, transmission
jacks, etc.
 Lift-up or lower the vehicle when necessary.
Make sure to support the correct positions.

ME(H4DOTC)-31
MECHANICAL
Compression
2. Compression
A: INSPECTION
CAUTION:
After warming-up, engine becomes very hot. Be
careful not to burn yourself during measure-
ment.
1) After warming-up the engine, turn the ignition
switch to OFF.
2) Make sure that the battery is fully charged.
3) Release the fuel pressure. FU(H4DOTC)-54, RELEASING OF FUEL PRES-
SURE, OPERATION, Fuel.>
4) Remove all the spark plugs. IG(H4DOTC)-5, REMOVAL, Spark Plug.>
5) Fully open the throttle valve.
6) Check the starter motor for satisfactory perfor-
mance and operation.
7) Hold the compression gauge tight against spark
plug hole.
NOTE:
When using a screw-in type compression gauge,
the screw (put into cylinder head spark plug hole)
should be less than 18 mm (0.71 in) long.
8) Crank the engine by means of starter motor, and
then read the maximum value on the gauge when
the pointer is steady.9) Perform at least two measurements per cylinder,
and make sure that the values are correct.
Compression (350 rpm and fully open throttle):
Standard
981 — 1,177 kPa (10 — 12 kgf/cm
2, 142 —
171 psi)
Limit
882 kPa (9.0 kgf/cm
2, 128 psi)
Difference between cylinders
Less than 49 kPa (0.5 kgf/cm
2, 7 psi)
ME-00007

ME(H4DOTC)-32
MECHANICAL
Idle Speed
3. Idle Speed
A: INSPECTION
1. USING SUBARU SELECT MONITOR
1) Before checking the idle speed, check the fol-
lowing:
(1) Ensure the air cleaner element is free from
clogging, ignition timing is correct, spark plugs
are in good condition, and that the hoses are
connected 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) Insert the cartridge to Subaru Select Monitor.
5) Connect the Subaru Select Monitor to data link
connector.
6) Turn the ignition switch to ON, and Subaru Se-
lect Monitor switch to ON.
7) Select the {2. Each System Check} in Main
Menu.
8) Select the {Engine Control System} in Selection
Menu.
9) Select the {1. Current Data Display & Save} in
Engine Control System Diagnosis.
10) Select the {1.12 Data Display} in Data Display
Menu.
11) Start the engine, and then read the engine idle
speed.
12) 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 neutral]:
700
±100 rpm
13) Check the idle speed when loaded. (Turn the
air conditioning switch to “ON” and operate the
compressor for at least 1 minute before measure-
ment.)
Idle speed [A/C “ON”, no load and gears in neu-
tral]:
A/C Refrigerant pressure (LOW)
MT: 725
±100 rpm
AT: 750
±100 rpm
A/C Refrigerant pressure (HIGH)
MT: 800
±100 rpm
AT: 825
±100 rpm
NOTE:
As idle speed is controlled by the automatic adjust-
ment type, it can not be adjusted manually. If the
idle speed is out of specifications, refer to General
On-board Diagnosis Table under “Engine Control
System”. tics Procedure.>

ME(H4DOTC)-33
MECHANICAL
Ignition Timing
4. Ignition Timing
A: INSPECTION
1. USING SUBARU SELECT MONITOR
1) Before checking the ignition timing speed, check
the following:
(1) Ensure the air cleaner element is free from
clogging, spark plugs are in good condition, and
that hoses are connected 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) Insert the cartridge to Subaru Select Monitor.
5) Connect the Subaru Select Monitor to data link
connector.
6) Turn the ignition switch to ON, and Subaru Se-
lect Monitor switch to ON.
7) Select the {2. Each System Check} in Main
Menu.
8) Select the {Engine Control System} in Selection
Menu.
9) Select the {1. Current Data Display & Save} in
Engine Control System Diagnosis.
10) Select the {1.12 Data Display} in Data Display
Menu.
11) Start the engine and check the ignition timing at
idle speed.
Ignition timing [BTDC/rpm]:
2.0 L model
12
°±10°/700
2.5 L model
17
°±10°/700
If the timing is not correct, check the ignition control
system. Refer to Engine Control System. EN(H4DOTC)-2, Basic Diagnostics Procedure.>

ME(H4DOTC)-35
MECHANICAL
Engine Oil Pressure
6. Engine Oil Pressure
A: INSPECTION
1) Remove the oil pressure switch from engine cyl-
inder block. Pressure Switch.>
2) Connect the oil pressure gauge hose to cylinder
block.
3) Connect the battery ground cable to battery.
4) Start the engine, and then measure the oil pres-
sure.
Oil pressure:
98 kPa (1.0 kg/cm
2, 14 psi) or more at 800 rpm
294 kPa (3.0 kg/cm2, 43 psi) or more at 5,000
rpm
 If the oil pressure is out of specification, check oil
pump, oil filter and lubrication line. LU(H4SO)-24, INSPECTION, Engine Lubrication
System Trouble in General.>
 If the oil pressure warning light is turned ON and
oil pressure is in specification, replace the oil pres-
sure switch. Engine Lubrication System Trouble in General.>
NOTE:
The specified data is based on an engine oil tem-
perature of 80°C (176°F).
5) After measuring the oil pressure, install the oil
pressure switch. LATION, Oil Pressure Switch.>
Tightening torque:
25 N
⋅m (2.5 kgf-m, 18.1 ft-lb)
FU-00009
ME-00009

ME(H4DOTC)-36
MECHANICAL
Fuel Pressure
7. Fuel Pressure
A: INSPECTION
CAUTION:
Before removing the fuel pressure gauge, re-
lease the fuel pressure.
NOTE:
If out of specification, check or replace the pressure
regulator and pressure regulator vacuum hose.
1) Release the fuel pressure. FU(H4DOTC)-54, RELEASING OF FUEL PRES-
SURE, OPERATION, Fuel.>
2) Open the fuel filler flap lid, and then remove the
fuel filler cap.
3) Disconnect the fuel delivery hoses from fuel fil-
ter, and then connect the fuel pressure gauge.
4) Connect the connector of fuel pump relay.
5) Start the engine.6) Measure the fuel pressure while disconnecting
the pressure regulator vacuum hose from intake
manifold.
Fuel pressure:
Standard; 284 — 314 kPa (2.9 — 3.2 kgf/cm2,
41 — 46 psi)
7) After connecting the pressure regulator vacuum
hose, measure the fuel pressure.
Fuel pressure:
Standard; 230 — 260 kPa (2.35 — 2.65 kgf/
cm
2, 33 — 38 psi)
NOTE:
The fuel pressure gauge registers 10 to 20 kPa (0.1
to 0.2 kgf/cm
2, 1 to 3 psi) higher than standard val-
ues during high-altitude operations.
ME-00010
FU-00262
ME-00011
ME-00011