Ford Mustang (1999-2004) Service Manual: Symptom Chart

Condition Possible Sources Action
  • Difficult starting
  • Damaged ignition system.
  • Damaged fuel system.
  • Damaged starting system.
  • Damaged charging system/battery.
  • Burnt valve.
  • Worn piston.
  • Worn piston rings.
  • Damaged head gasket
  • Damaged cooling system.
  • Refer to the appropriate section in Group 303 for the procedure.

    REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.

  • Refer to the appropriate section in Group 303 for the procedure.

    REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual

  • Refer to the appropriate section in Group 303 for the procedure. REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual
  • INSTALL a new valve.
  • INSTALL a new piston.
  • INSTALL new piston rings.
  • REPAIR or INSTALL a new cylinder block
  • INSTALL a new head gasket.
  • Refer to the appropriate section in Group 303 for the procedure.

    REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.
  • Poor idling
  • Vacuum leaks.
  • Malfunctioning or damaged ignition system.
  • Malfunctioning or damaged fuel system.
  • Damaged valve tappet or lash adjuster.
  • Damaged valve tappet guide or lash adjuster.
  • Incorrect valve-tovalve seat contact
  • Damaged head gasket
  • Refer to the appropriate section in Group 303 for the procedure.

    REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.

  • Refer to the appropriate section in Group 303 for the procedure.

    REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.

  • Refer to the appropriate section in Group 303 for the procedure.

    REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual

  • INSTALL a new valve tappet or lash adjuster
  • INSTALL a new valve tappet guide or valve tappet
  • REPAIR or INSTALL a new valve or valve seat.
  • INSTALL a new head gasket.
  • Abnormal combustion
  • Malfunctioning or damaged fuel system.
  • Malfunctioning or damaged ignition system.
  • Malfunctioning or damaged air intake system.
  • Damaged valve tappet or lash adjuster.
  • Damaged valve tappet guide or valve tappet.
  • Burnt or sticking valve.
  • Weak or broken valve spring.
  • Carbon accumulation in combustion chamber
  • Refer to the appropriate section in Group 303 for the procedure.

    REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.

  • Refer to the appropriate section in Group 303 for the procedure.

    REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.

  • Refer to the appropriate section in Group 303 for the procedure.

    REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.

  • INSTALL a new valve tappet or lash adjuster.
  • INSTALL a new valve tappet guide or valve tappet.
  • REPAIR or INSTALL a new valve.
  • INSTALL a new valve spring.
  • ELIMINATE carbon buildup.
  • Excessive oil consumption
  • Leaking oil.
  • Malfunctioning PCV system
  • Worn valve stem seal.
  • Worn valve stem or valve guide.
  • Sticking piston rings.
  • Worn piston ring groove.
  • Worn piston or cylinder
  • REPAIR oil leakage.
  • REPAIR or INSTALL new necessary components
  • INSTALL a new valve stem seal.
  • INSTALL a new valve and valve guide.
  • REPAIR or INSTALL new piston rings.
  • INSTALL a new piston and piston pin
  • REPAIR or INSTALL a new piston or cylinder block
  • Engine noise
  • Leaking exhaust system
  • Incorrect drive belt tension.
  • Malfunctioning generator bearing
  • Malfunctioning water pump bearing.
  • Malfunctioning or damaged cooling system.
  • Malfunctioning or damaged fuel system.
  • Loose timing chain/belt (6268).
  • Damaged timing chain tensioner (6L266).
  • Excessive main bearing clearance.
  • Seized or heat damaged crankshaft main bearing.
  • Excessive crankshaft end play.
  • Excessive connecting rod bearing clearance.
  • Heat damaged connecting rod bearing (6211).
  • Damaged connecting rod bushing (6207).
  • Worn cylinder.
  • Worn piston (6108) or piston pin (6135).
  • Damaged piston rings.
  • Bent connecting rod.
  • Malfunctioning valve tappet (6500) or lash adjuster.
  • Excessive valve tappet or lash adjuster clearance.
  • Broken valve spring (6513).
  • Excessive valve guide clearance.
  • REPAIR exhaust leakage.
  • Refer to the appropriate section in Group 414 for the procedure.
  • Refer to the appropriate section in Group 303 for the procedure.

    REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.

  • ADJUST or INSTALL a new timing chain/belt.
  • INSTALL a new timing chain tensioner
  • ADJUST clearance or INSTALL a new crankshaft main bearing (6333).
  • INSTALL a new crankshaft main bearing.
  • INSTALL a new thrust bearing or crankshaft (6303).
  • INSTALL a new connecting rod bearing or connecting rod (6200).
  • INSTALL a new connecting rod bearing.
  • INSTALL a new connecting rod bushing.
  • REPAIR or INSTALL a new cylinder block (6010).
  • INSTALL a new piston or piston pin.
  • INSTALL new piston rings
  • INSTALL a new connecting rod.
  • INSTALL a new valve tappet or lash adjuster.
  • ADJUST clearance or INSTALL a new valve tappet guide or valve tappet.
  • INSTALL a new valve spring.
  • ADJUST clearance or INSTALL a new valve guide (6510) or valve.
  • Insufficient power
  • Malfunctioning or damaged ignition system.
  • Malfunctioning or damaged fuel system.
  • Malfunctioning or damaged air intake system.
  • Damaged or plugged exhaust system.
  • Incorrect tire size.
  • Dragging brakes.
  • Slipping transmission.
  • Malfunctioning valve tappet or lash adjuster.
  • Damaged valve tappet guide or valve tappet.
  • Compression leakage at valve seat.
  • Seized valve stem.
  • Weak or broken valve spring
  • Worn or damaged camshaft.
  • Damaged head gasket (6051).
  • Cracked or distorted cylinder head
  • Damaged, worn or sticking piston ring (s).
  • Worn or damaged piston.
  • Refer to the appropriate section in Group 303 for the procedure.

    REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual

  • Refer to the appropriate section in Group 303 for the procedure.

    REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.

  • Refer to the appropriate section in Group 303 for the procedure.

    REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.

  • INSPECT exhaust system.
  • Refer to the appropriate section in Group 307 for the procedure.
  • INSTALL a new valve tappet or lash adjuster
  • INSTALL a new valve tappet guide or valve tappet.
  • REPAIR or INSTALL a new valve, valve seat or cylinder head (6049).
  • INSTALL a new valve.
  • INSTALL a new valve spring.
  • INSTALL a new camshaft.
  • INSTALL a new head gasket.
  • INSTALL a new cylinder head.
  • REPAIR or INSTALL a new piston ring(s).
  • INSTALL a new piston and piston pin.
    Inspection and Verification
    1. Verify the customer concern by operating the engine to duplicate the condition. 2. Visually inspect for obvious signs of mechanical damage. Refer to the following chart. Visual Inspection Ch ...

    Component Tests
    Engine Oil Leaks NOTE: When diagnosing engine oil leaks, the source and location of the leak must be positively identified prior to repair. Prior to carrying out this procedure, clean all sealin ...

    Other materials:

    Cleaning the engine
    Engines are more efficient when they are clean because grease and dirt buildup keep the engine warmer than normal. When washing: • Take care when using a power washer to clean the engine. The high-pressure fluid could penetrate the sealed parts and cause da ...

    Air Bag Supplemental Restraint System (SRS) (Diagnosis and Testing)
    Refer to Wiring Diagrams Cell 46 , Air Bag for schematic and connector information. Special Tool(s) Diagnostic Tool, Restraint System 418-F088 (105-R0012) Restraint System Diagnostic Tool Warning WARNING: This tool is for restraint system se ...

    Piston - Pin Diameter
    1. Measure the piston pin diameter in two directions at the points shown. Verify the diameter is within specification. Refer to the appropriate section in Group for the procedure. If out of specification, install new components as necessary. Refer ...