LEMON Manuals: Even more car manuals for everyone
Home >> Subaru >> 2017 >> Forester 2.0XT Touring >> Repair and Diagnosis >> Engine Mechanical >> Mechanical >> Engine Mechanical (H4DOTC) >> Engine Trouble in General >> Inspection

Engine Trouble in General: Inspection

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

A - Very often 

B - Sometimes 

C - Rarely 

Symptoms 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 C
Defective starter B
Battery Improper connection of terminal A
Rundown 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
Immobilizer system Ref. to IMMOBILIZER (DIAGNOSTICS)>Basic Diagnostic Procedure . A
  1. 2) Initial combustion does not occur.
 Starter Defective starter C
Engine control system Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Basic Diagnostic Procedure . A
Fuel line Defective fuel pump and relay A
Clogged fuel line C
Lack of fuel or insufficient fuel B
Timing chain Trouble B
Defective timing B
Compression Incorrect cam clearance C
Loosened spark plug or defective gasket C
Loosened cylinder head bolt or defective cylinder head gasket C
Improper valve sealing C
Defective valve stem C
Worn or broken valve spring B
Worn or stuck piston rings, cylinder liner and piston C
Incorrect valve timing B
Improper engine oil (low viscosity) B
  1. 3) Initial combustion occurs.
 Engine control system Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Basic Diagnostic Procedure . 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 fuel or insufficient fuel B
Timing chain Trouble B
Defective timing B
Compression Incorrect cam clearance C
Loosened spark plug or defective gasket C
Loosened cylinder head bolt or defective cylinder head gasket C
Improper valve sealing C
Defective valve stem C
Worn or broken valve spring B
Worn or stuck piston rings, cylinder liner and piston C
Incorrect valve timing B
Improper engine oil (low viscosity) B
  1. 4) Engine stalls after initial combustion.
 Engine control system Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Basic Diagnostic Procedure . 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 fuel or insufficient fuel B
Timing chain Trouble B
Defective timing B
Compression Incorrect cam clearance C
Loosened spark plug or defective gasket C
Loosened cylinder head bolt or defective cylinder head gasket C
Improper valve sealing 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
  1. 2. Rough idle and engine stall
 Engine control system Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Basic Diagnostic Procedure . 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 fuel or insufficient fuel B
Timing chain Defective timing C
Compression Incorrect cam clearance B
Loosened spark plug or defective gasket B
Loosened cylinder head bolt or defective cylinder head gasket B
Improper valve sealing 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 Over-heating C
Other Evaporative emission control system malfunction A
Stuck or damaged throttle valve B
  1. 3. Low output, hesitation and poor acceleration
 Engine control system Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Basic Diagnostic Procedure . 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 fuel or insufficient fuel C
Timing chain Defective timing B
Compression Incorrect cam clearance B
Loosened spark plug or defective gasket B
Loosened cylinder head bolt or defective cylinder head gasket B
Improper valve sealing 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 Over-heating C
Over-cooling C
Other Evaporative emission control system malfunction A
  1. 4. Surging
 Engine control system Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Basic Diagnostic Procedure . 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 fuel or insufficient fuel C
Timing chain Defective timing B
Compression Incorrect cam clearance B
Loosened spark plug or defective gasket C
Loosened cylinder head bolt or defective cylinder head gasket C
Improper valve sealing 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 Over-heating B
Other Evaporative emission control system malfunction C
  1. 5. Engine does not return to idle.
 Engine control system Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Basic Diagnostic Procedure . A
Intake system Loosened or cracked vacuum hose A
Other Stuck or damaged throttle valve A
  1. 6. Dieseling (run-on)
 Engine control system Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Basic Diagnostic Procedure . A
Cooling system Over-heating B
Other Evaporative emission control system malfunction B
  1. 7. After burning in exhaust system
 Engine control system Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Basic Diagnostic Procedure . 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
Timing chain Defective timing B
Compression Incorrect cam clearance B
Loosened spark plug or defective gasket C
Loosened cylinder head bolt or defective cylinder head gasket C
Improper valve sealing 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
Other Evaporative emission control system malfunction C
  1. 8. Knocking
 Engine control system Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Basic Diagnostic Procedure . A
Intake system Loosened oil filler cap B
Timing chain Defective timing B
Compression Incorrect cam clearance C
Incorrect valve timing B
Cooling system Over-heating A
  1. 9. Excessive engine oil consumption
 Intake 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 chain cover attaching bolts and defective gasket B
Defective oil filter gasket B
Defective crankshaft oil seal B
Defective rocker cover gasket B
Loosened oil drain plug or defective gasket B
Loosened oil pan mounting bolt or defective oil pan B
  1. 10. Excessive fuel consumption
 Engine control system Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Basic Diagnostic Procedure . A
Intake system Dirty air cleaner element A
Timing chain Defective timing B
Compression Incorrect cam clearance B
Loosened spark plug or defective gasket C
Loosened cylinder head bolt or defective cylinder gasket C
Improper valve sealing 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
scientia non olet · About LEMON Manuals