Contents Section: Mechanical All sections

Engine Mechanical (H4SO): Diagnosis Subaru Outback BP рестайлинг

Mechanical 11 illustrations ~1579 words

INSPECTION

CAUTIONAfter warming-up, engine becomes very hot. Be careful not to burn yourself during measurement.

Scheme 75

Scheme 75
  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. RELEASING OF FUEL PRESSURE , PROCEDURE, Fuel .>
  4. Remove all spark plugs. REMOVAL , Spark Plug .>
  5. Fully open the throttle valve.
  6. Check the starter motor for satisfactory performance and operation.
  7. Hold the compression gauge tightly against the 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 the starter motor, and read the maximum value on the gauge when the needle of gauge 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: 1,020 - 1,275 kPa (10.4 - 13.0 kgf/cm 2 , 148 - 185 psi) Difference between cylinders: 49 kPa (0.5 kgf/cm 2 , 7 psi), or less

Scheme 76

Scheme 76: INSPECTION
  1. Before checking the idle speed, check the following item: Check the air cleaner element is free from clogging, ignition timing is correct, spark plugs are in good condition, and hoses are connected properly. Check the malfunction indicator light does not illuminate.
  2. Warm-up the engine.
  3. Stop the engine, and turn the ignition switch to OFF.
  4. Connect the Subaru Select Monitor to the data link connector.
  5. Turn the ignition switch to ON and run the Subaru Select Monitor.
  6. Select {Each System Check} in Main Menu.
  7. Select {Engine Control System} in Selection Menu.
  8. Select {Current Data Display & Save} in Engine Control System Diagnosis.
  9. Select {Data Display} in Data Display Menu.
  10. Start the engine, and read the engine idle speed.
  11. Check the idle speed when no-loaded. (Headlight, heater fan, rear defroster, radiator fan, A/C and etc. are OFF) Idle speed [No load and gears in "N" or "P" range]: 650±100 rpm (MT model) 700±100 rpm (AT model)
  12. Check the idle speed when loaded. (Turn the A/C switch to "ON" and operate the compressor for at least one minute before measurement.) Idle speed [A/C "ON" and gears in "N" or "P" range]: 850±100 rpm NOTE: Idle speed cannot be adjusted manually, because the idle speed is automatically adjusted. If the prescribed idle speed cannot be maintained, refer to the General On-board Diagnosis Table under "Engine Control System". BASIC DIAGNOSTIC PROCEDURE . >

Scheme 77

Scheme 77: INSPECTION
  1. Before checking the ignition timing, check the following item: Check the air cleaner element is free from clogging, spark plugs are in good condition, and hoses are connected properly. Check the malfunction indicator light does not illuminate.
  2. Warm-up the engine.
  3. When checking the ignition timing, connect the timing light to the #1 cylinder spark plug cord and illuminate the timing mark with the timing light.
  4. Start the engine and check the ignition timing at idle speed as shown below. Ignition timing [BTDC/rpm]: 10°±8°/650 (MT Model) 15°±8°/700 (AT model) If the timing is not correct, check the ignition control system. BASIC DIAGNOSTIC PROCEDURE . >

Scheme 78

Scheme 78: INSPECTION
  1. Warm-up the engine.
  2. Disconnect the brake vacuum hose from intake manifold, and then install the vacuum gauge.
  3. Keep the engine at idle speed and read the vacuum gauge indication. By observing the gauge needle movement, internal condition of the engine can be diagnosed as described below. Vacuum pressure (at idling, A/C "OFF"): Less than -60.0 kPa (-450 mmHg, -17.72 inHg) INTAKE MANIFOLD VACUUM DIAGNOSIS CHART Diagnosis of engine condition by measurement of intake manifold vacuum Vacuum gauge indication Possible engine condition 1. Needle is steady but lower than normal position. This tendency becomes more evident as engine temperature rises. Air leakage around intake manifold gasket, disconnection or damage of vacuum hose 2. Needle intermittently drops to position lower than normal position. Leakage around cylinder 3. Needle drops suddenly and intermittently from normal position. Sticky valve 4. When engine speed is gradually increased, needle begins to vibrate rapidly at certain speed, and then vibration increases as engine speed increases. Weak or broken valve springs 5. Needle vibrates above and below normal position in narrow range. Defective ignition system

Scheme 79

Scheme 79: INSPECTION

Scheme 80

Scheme 80
  1. Remove the oil pressure switch. REMOVAL , Oil Pressure Switch .>
  2. Connect the oil pressure gauge to cylinder block.
  3. Connect the ground cable to battery.
  4. Start the engine, and measure the oil pressure. Oil pressure: Standard: 98 kPa (1.0 kg/cm 2 , 14 psi) or more at 600 rpm 294 kPa (3.0 kg/cm 2 , 43 psi) or more at 5,000 rpm If the oil pressure is out of specification, check the oil pump, oil filter and lubrication line. INSPECTION , Engine Lubrication System Trouble in General .> If the oil pressure warning light is ON and oil pressure is within specification, check the oil pressure switch. INSPECTION , Engine Lubrication System Trouble in General .> NOTE: Standard value is based on an engine oil temperature of 80°C (176°F).
  5. After measuring the oil pressure, install the oil pressure switch. INSTALLATION , Oil Pressure Switch .> Tightening torque: 25 N.m (2.5 kgf-m, 18.1 ft-lb)
CAUTIONBefore removing the fuel pressure gauge, release the fuel pressure.

Note. Check or replace the fuel pump and fuel delivery line if the fuel pressure is out of the standard.

Scheme 81

Scheme 81
  1. Release the fuel pressure. RELEASING OF FUEL PRESSURE , PROCEDURE, Fuel .>
  2. Disconnect the fuel delivery hose from the fuel damper, and connect the fuel pressure gauge.
  3. Install the fuse of fuel pump to main fuse box.
  4. Start the engine.
  5. Measure the fuel pressure after warming up the engine. Fuel pressure: Standard: 339.5 - 360.5 kPa (3.5 - 3.7 kg/cm 2 , 49 - 52 psi) NOTE: The fuel pressure gauge registers 10 to 20 kPa (0.1 to 0.2 kg/cm 2 , 1 to 3 psi) higher than standard values during high-altitude operations.

Note. Inspection and adjustment of valve clearance should be performed while engine is cold.

Scheme 82

Scheme 82

Scheme 83

Scheme 83

Scheme 84

Scheme 84
  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 the battery.
  6. Remove the timing belt cover (LH).
  7. Remove the fuel injector. REMOVAL , Fuel Injector .>
  8. When inspecting #1 and #3 cylinders: Disconnect the spark plug cords from spark plugs RH side. RH SIDE , REMOVAL, Spark Plug .> Disconnect the PCV hose from the rocker cover (RH). Remove the bolts, then remove the rocker cover (RH).
  9. When inspecting #2 and #4 cylinders: Disconnect the spark plug cords from spark plugs (LH side). LH SIDE , REMOVAL, Spark Plug .> Disconnect the PCV hose from the rocker cover (LH). Remove the bolts, then remove the rocker cover (LH).
  10. Set #1 cylinder piston to top dead center of compression stroke by rotating the crank pulley clockwise using the socket wrench. NOTE: When the arrow mark (A) on cam sprocket (LH) comes exactly to the top, #1 cylinder piston is brought to the top dead center of compression stroke.
  11. Measure #1 cylinder valve clearance by using thickness gauge. NOTE: Insert the thickness gauge (A) in as horizontally as possible with respect to the valve stem end face. Lift up the vehicle and measure the exhaust valve clearances. 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)
  12. If necessary, adjust the valve clearance. ADJUSTMENT, Valve Clearance .>
  13. Measure the valve clearance in #3, #2 and #4 cylinder in the same measurement procedure as #1 cylinder in this order. NOTE: Be sure to set the cylinder pistons to their respective top dead centers on compression stroke before measuring valve clearances. By rotating the crank pulley clockwise every 180° from the state that #1 cylinder piston is on the top dead center of compression stroke, #3, #2 and #4 cylinder pistons come to the top dead center of compression stroke in this order.
  14. After inspection, install the related parts in the reverse order of removal.
  1. Check that pipes, hoses, connectors and clamps are installed firmly.
  2. Check the engine coolant and ATF are at specified levels.
  3. Start the engine and check for exhaust gas, engine coolant, leaks of fuel, etc. Also check for noise and vibrations.

Make sure that no crack or other damages do not exist.

Scheme 85

Scheme 85: PROCEDURE
  1. After removing the engine from body, secure it to ST in the following procedure. ST1 498457000 ENGINE STAND ADAPTER RH ST2 498457100 ENGINE STAND ADAPTER LH ST3 499817100 ENGINE STAND
  2. In this section the procedures described under each index are all connected and stated in order. The procedure for overhauling of the engine will be completed when you go through all steps in the process. Therefore, in this section, to conduct the particular procedure within the flow of a section, you need to go back and conduct the procedure described previously in order to do that particular procedure.
  1. Make sure the V-belt is not worn or otherwise damaged.
  2. Check the tension of the belt. INSPECTION, V-belt .>

Check the cover for damage.

  1. Check the cam sprocket teeth for abnormal wear and scratches.
  2. Make sure there is no free play between cam sprocket and key.
  3. Check the cam sprocket protrusion used for sensor for damage and contamination of foreign matter.
  1. Check the crank sprocket teeth for abnormal wear and scratches.
  2. Make sure there is no free play between crank sprocket and key.
  3. Check the crank sprocket protrusion used for sensor for damage and contamination of foreign matter.

Note. The "RANK" shown in the chart shows the possibilities of the cause of trouble in order from "Very often" to "Rarely".

SymptomsProblem parts etc.Possible causeRANK
1. Engine does not start.
1) Starter does not turn.StarterDefective battery-to-starter harnessB
Defective starter switchC
Defective inhibitor switchC
Defective starterB
BatteryImproper connection of the terminalA
Run-down batteryA
Defective charging systemB
FrictionSeizure of crankshaft and connecting rod bearingC
Seized camshaftC
Seized or stuck piston and cylinderC
2) Initial combustion does not occur.StarterDefective starterC
Engine control system BASIC DIAGNOSTIC PROCEDURE . >A
Fuel lineDefective fuel pump and relayA
Clogged fuel lineB
Lack of or insufficient fuelB
Timing beltDegradation, etc.B
Defective timingB
CompressionIncorrect valve clearanceC
Loosened spark plug or defective gasketC
Loosened cylinder head bolt or defective gasketC
Improper valve sealingC
Defective valve stemC
Worn or broken valve springB
Worn or stuck piston rings, cylinder and pistonC
Incorrect valve timingB
Improper engine oil (low viscosity)B
3) Initial combustion occurs.Engine control system BASIC DIAGNOSTIC PROCEDURE . >A
Intake systemDefective intake manifold gasketB
Defective throttle body gasketB
Fuel lineDefective fuel pump and relayC
Clogged fuel lineC
Lack of or insufficient fuelB
Timing beltDegradation, etc.B
Defective timingB
CompressionIncorrect valve clearanceC
Loosened spark plug or defective gasketC
Loosened cylinder head bolt or defective gasketC
Improper valve sealingC
Defective valve stemC
Worn or broken valve springB
Worn or stuck piston rings, cylinder and pistonC
Incorrect valve timingB
Improper engine oil (low viscosity)B
4) Engine stalls after initial combustion.Engine control system BASIC DIAGNOSTIC PROCEDURE . >A
Intake systemLoosened or cracked intake ductB
Loosened or cracked PCV hoseC
Loosened or cracked vacuum hoseC
Defective intake manifold gasketB
Defective throttle body gasketB
Dirty air cleaner elementC
Fuel lineClogged fuel lineC
Lack of or insufficient fuelB
Timing beltDegradation, etc.B
Defective timingB
CompressionIncorrect valve clearanceC
Loosened spark plug or defective gasketC
Loosened cylinder head bolt or defective gasketC
Improper valve sealingC
Defective valve stemC
Worn or broken valve springB
Worn or stuck piston rings, cylinder and pistonC
Incorrect valve timingB
Improper engine oil (low viscosity)B
2. Rough idle and engine stallEngine control system BASIC DIAGNOSTIC PROCEDURE . >A
Intake systemLoosened or cracked intake ductA
Loosened or cracked PCV hoseA
Loosened or cracked vacuum hoseA
Defective intake manifold gasketB
Defective throttle body gasketB
Defective PCV valveC
Loosened oil filler capB
Dirty air cleaner elementC
Fuel lineDefective fuel pump and relayC
Clogged fuel lineC
Lack of or insufficient fuelB
Timing beltDefective timingC
CompressionIncorrect valve clearanceB
Loosened spark plug or defective gasketB
Loosened cylinder head bolt or defective gasketB
Improper valve sealingB
Defective valve stemC
Worn or broken valve springB
Worn or stuck piston rings, cylinder and pistonB
Incorrect valve timingA
Improper engine oil (low viscosity)B
Lubrication systemIncorrect oil pressureB
Defective rocker cover gasketC
Cooling systemOverheatingC
OthersEvaporative emission control system malfunctionA
Stuck or damaged throttle valveB
3. Low output, hesitation and poor accelerationEngine control system BASIC DIAGNOSTIC PROCEDURE . >A
Intake systemLoosened or cracked intake ductA
Loosened or cracked PCV hoseA
Loosened or cracked vacuum hoseB
Defective intake manifold gasketB
Defective throttle body gasketB
Defective PCV valveB
Loosened oil filler capB
Dirty air cleaner elementA
Fuel lineDefective fuel pump and relayB
Clogged fuel lineB
Lack of or insufficient fuelC
Timing beltDefective timingB
CompressionIncorrect valve clearanceB
Loosened spark plug or defective gasketB
Loosened cylinder head bolt or defective gasketB
Improper valve sealingB
Defective valve stemC
Worn or broken valve springB
Worn or stuck piston rings, cylinder and pistonC
Incorrect valve timingA
Improper engine oil (low viscosity)B
Lubrication systemIncorrect oil pressureB
Cooling systemOverheatingC
Over-coolingC
OthersEvaporative emission control system malfunctionA
4. SurgingEngine control system BASIC DIAGNOSTIC PROCEDURE . >A
Intake systemLoosened or cracked intake ductA
Loosened or cracked PCV hoseA
Loosened or cracked vacuum hoseA
Defective intake manifold gasketB
Defective throttle body gasketB
Defective PCV valveB
Loosened oil filler capB
Dirty air cleaner elementB
Fuel lineDefective fuel pump and relayB
Clogged fuel lineB
Lack of or insufficient fuelC
Timing beltDefective timingB
CompressionIncorrect valve clearanceB
Loosened spark plug or defective gasketC
Loosened cylinder head bolt or defective gasketC
Improper valve sealingC
Defective valve stemC
Worn or broken valve springC
Worn or stuck piston rings, cylinder and pistonC
Incorrect valve timingA
Improper engine oil (low viscosity)B
Cooling systemOverheatingB
OthersEvaporative emission control system malfunctionC
5. Engine does not return to idle.Engine control system BASIC DIAGNOSTIC PROCEDURE . >A
Intake systemLoosened or cracked vacuum hoseA
OthersStuck or damaged throttle valveA
6. Dieseling (Run-on)Engine control system BASIC DIAGNOSTIC PROCEDURE . >A
Cooling systemOverheatingB
OthersEvaporative emission control system malfunctionB
7. After burning in exhaust systemEngine control system BASIC DIAGNOSTIC PROCEDURE . >A
Intake systemLoosened or cracked intake ductC
Loosened or cracked PCV hoseC
Loosened or cracked vacuum hoseB
Defective PCV valveB
Loosened oil filler capC
Timing beltDefective timingB
CompressionIncorrect valve clearanceB
Loosened spark plug or defective gasketC
Loosened cylinder head bolt or defective gasketC
Improper valve sealingB
Defective valve stemC
Worn or broken valve springC
Worn or stuck piston rings, cylinder and pistonC
Incorrect valve timingA
Lubrication systemIncorrect oil pressureC
Cooling systemOver-coolingC
OthersEvaporative emission control system malfunctionC
8. KnockingEngine control system BASIC DIAGNOSTIC PROCEDURE . >A
Intake systemLoosened oil filler capB
Timing beltDefective timingB
CompressionIncorrect valve clearanceC
Incorrect valve timingB
Cooling systemOverheatingA
9. Excessive engine oil consumptionIntake systemLoosened or cracked PCV hoseA
Defective PCV valveB
Loosened oil filler capC
CompressionDefective valve stemA
Worn or stuck piston rings, cylinder and pistonA
Lubrication systemLoosened oil pump attaching bolts and defective gasketB
Defective oil filter sealB
Defective crankshaft oil sealB
Defective rocker cover gasketB
Loosened oil drain plug or defective gasketB
Loosened oil pan fitting bolts or defective oil panB
10. Excessive fuel consumptionEngine control system BASIC DIAGNOSTIC PROCEDURE . >A
Intake systemDirty air cleaner elementA
Timing beltDefective timingB
CompressionIncorrect valve clearanceB
Loosened spark plug or defective gasketC
Loosened cylinder head bolt or defective gasketC
Improper valve sealingB
Defective valve stemC
Worn or broken valve springC
Worn or stuck piston rings, cylinder and pistonB
Incorrect valve timingB
Lubrication systemIncorrect oil pressureC
Cooling systemOver-coolingC
A - Very often B - Sometimes C - Rarely

SYMPTOM POSSIBLE CAUSE

Type of soundConditionPossible cause
Regular clicking soundSound increases as engine speed increases.Valve mechanism is defective. Incorrect valve clearance Worn valve rocker Worn camshaft Broken valve spring
Heavy and dull clankOil pressure is low.Worn crankshaft main bearing Worn connecting rod bearing (large end)
Oil pressure is normal.Damaged engine mounting
High-pitched clank (Spark knock)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 1,000 to 2,000 rpmSound is reduced when fuel injector connector of noisy cylinder is disconnected ( (1) ).Worn crankshaft main bearing Worn connecting rod bearing (large end)
Knocking sound when engine is operating under idling speed and engine is warmSound is reduced when fuel injector connector of noisy cylinder is disconnected ( (1) ).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 disconnected in turn ( (1) ).Worn cam sprocket Worn camshaft journal bore in cylinder head assembly
Squeaky soundInsufficient generator lubrication
Rubbing soundPoor contact of generator brush and rotor
Gear scream when starting engineDefective ignition starter switch Worn gear and starter pinion
Sound like polishing glass with a dry clothLoose drive belt Defective water pump shaft
Hissing soundInsufficient compression Air leakage in air intake system, hose, connection or manifold
Timing belt noiseLoose timing belt Belt contacting with case/adjacent part
Valve noiseIncorrect valve clearance
NOTE: (1) When disconnecting the fuel injector connector, the malfunction indicator light illuminates and DTC is stored in ECM memory. Therefore, perform the Clear Memory Mode OPERATION , Clear Memory Mode .> and Inspection Mode PROCEDURE , Inspection Mode .> after connecting the fuel injector connector.
NOTE
(1) When disconnecting the fuel injector connector, the malfunction indicator light illuminates and DTC is stored in ECM memory. Therefore, perform the Clear Memory Mode OPERATION , Clear Memory Mode .> and Inspection Mode PROCEDURE , Inspection Mode .> after connecting the fuel injector connector.
(1)When disconnecting the fuel injector connector, the malfunction indicator light illuminates and DTC is stored in ECM memory. Therefore, perform the Clear Memory Mode OPERATION , Clear Memory Mode .> and Inspection Mode PROCEDURE , Inspection Mode .> after connecting the fuel injector connector.

CONDITION POSSIBLE CAUSE