• Ancillary Components Binding
• Intake Air Restriction
• Crossed Spark Plug Wires
• Spark Plugs Fouled
• Fuel System Failure
• Low Fuel Pressure
• Low Cylinder Compression
• Poor Quality or Contaminated Fuel
• Carbon Build-up
• Wrong Spark Plugs (Too High Heat Range)
• Fuel Delivery System
• PCV System
• Fuel Selection Timing
• Cylinder Hot Spots
• Positive Crankcase Ventilation (PCV) System
• Oil Viscosity
• External Leaks
• Improper Oil Dipstick
• Valve Seals
• Cylinder Wall Taper Excessive
• Worn Piston Rings
• Trapped Air
• Worn Drive Belt
• Worn Water Pump
• Stuck Thermostat
• Plugged Radiator (Internal & External)
• Dry Fuel System Running Rich
Exhaust System Concerns
(visible smoke) - Black Smoke
- Blue Smoke
• Ignition System
• Fuel Delivery System
• Sticking Fuel Injector
• High Fuel Pressure
• PCV System
• Worn Piston Rings
• Worn Valve Guides
• Leaky Lines
• Contaminated Fuel
• Excessive Alcohol in Fuel
• Incorrect Octane Rating
• Low Oil Pressure
• Oil Filter Restriction