Symptom Chart - Engine Performance
WARNING: This page is about a different car, the 2018 Ford F-550 Super Duty, 2018 Ford F-450 Super Duty, 2018 Ford F-350 Super Duty, and 2018 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
| Symptom | Possible Sources | Action |
|---|---|---|
| Difficult starting | Inoperative or damaged ignition system Air or vacuum leak Inoperative or damaged fuel system Inoperative or damaged starting system |
Refer to the appropriate Engine article for the procedure and refer to OEM Electrical Wiring Diagram Introduction . |
| Damaged charging system/ battery | REFER to: Charging System - 6.2L V8/6.8L Triton-30V - V10 . TEST the system for normal operation after the repair. | |
| Low oil pressure | CARRY OUT the oil pressure test. | |
| Burnt valve | INSTALL a new cylinder head. TEST the system for normal operation after the repair. | |
| Worn piston | INSTALL a new piston. TEST the system for normal operation after the repair. | |
| Worn piston rings | INSTALL new piston rings. TEST the system for normal operation after the repair. | |
| Worn cylinder | INSTALL a new cylinder block. TEST the system for normal operation after the repair. | |
| Damaged head gasket | INSTALL a new cylinder head gasket. TEST the system for normal operation after the repair. | |
| Inoperative or damaged cooling system | Refer to the appropriate Engine article for the procedure. | |
| Fail-safe cooling invoked (if equipped) | Refer to OEM Electrical Wiring Diagram Introduction . | |
| Poor idling | Vacuum leaks Inoperative or damaged EGR system |
Refer to the appropriate Engine article for the procedure and refer to OEM Electrical Wiring Diagram Introduction . |
| Inoperative or damaged ignition system | Refer to the appropriate Engine article for the procedure. | |
| Inoperative or damaged cooling system Inoperative or damaged fuel system |
Refer to the appropriate Engine article for the procedure. | |
| Fail-safe cooling invoked (if equipped) | Refer to OEM Electrical Wiring Diagram Introduction . | |
| Damaged hydraulic lash adjuster | INSTALL a new hydraulic lash adjuster. TEST the system for normal operation after the repair. | |
| Damaged rocker arm | INSTALL new components as necessary. TEST the system for normal operation after the repair. | |
| Incorrect valve-to-valve seat contact | INSTALL a new cylinder head. TEST the system for normal operation after the repair. | |
| Damaged head gasket | INSTALL a new cylinder head gasket. TEST the system for normal operation after the repair. | |
| Low oil pressure | CARRY OUT the oil pressure test. | |
| Engine runs rough | Inoperative or damaged fuel system Air or vacuum leaks EGR system fault Inoperative or damaged cooling system Inoperative or damaged ignition system |
Refer to the appropriate Engine article for the procedure. |
| Fail-safe cooling invoked (if equipped) | Refer to OEM Electrical Wiring Diagram Introduction . | |
| Malfunctioning or damaged air intake system | Refer to the appropriate Engine article for the Procedure and refer to OEM Electrical Wiring Diagram Introduction . | |
| Damaged hydraulic lash adjuster | INSTALL a new hydraulic lash adjuster. TEST the system for normal operation after the repair. | |
| Burnt or sticking valve | INSTALL a new valve. TEST the system for normal operation after the repair. | |
| Weak or broken valve spring | INSTALL a new valve spring. TEST the system for normal operation after the repair. | |
| Carbon accumulation in combustion chamber | ELIMINATE carbon buildup. TEST the system for normal operation after the repair. | |
| Excessive oil consumption | Leaking oil | REPAIR oil leakage. TEST the system for normal operation after the repair. |
| Malfunctioning PCV system | REPAIR or INSTALL new components as necessary. TEST the system for normal operation after the repair. | |
| Incorrect oil | CHANGE oil to correct specification. TEST the system for normal operation after the repair. | |
| Worn valve stem seal | INSTALL a new valve stem seal. TEST the system for normal operation after the repair. | |
| Worn valve stem or valve guide | INSTALL a new cylinder head. TEST the system for normal operation after the repair. | |
| Sticking piston rings | INSTALL new piston rings. TEST the system for normal operation after the repair. | |
| Worn piston ring groove | INSTALL a new piston and piston pin. TEST the system for normal operation after the repair. | |
| Worn piston or cylinder | INSTALL a new piston or cylinder block. TEST the system for normal operation after the repair. | |
| Insufficient power | Inoperative or damaged ignition system Air intake system blockage Lubrication system blockage Inoperative or damaged fuel system |
Refer to the appropriate Engine article for the procedure and refer to OEM Electrical Wiring Diagram Introduction . |
| Oil level too high | DRAIN oil to correct level. | |
| Incorrect engine oil | INSTALL correct specification engine oil. TEST the system for normal operation after the repair. | |
| Low oil pressure | CARRY OUT the oil pressure test. | |
| Excessive accessory drive belt loading Inoperative or damaged cooling system |
Refer to the appropriate Engine article for the procedure. | |
| Fail-safe cooling invoked (if equipped) | Refer to OEM Electrical Wiring Diagram Introduction . | |
| Damaged or plugged exhaust system | INSPECT exhaust system. TEST the system for normal operation after the repair. | |
| Incorrect tire size | REFER to: Suspension System . TEST the system for normal operation after the repair. | |
| Dragging brakes | REFER to: Brake System . TEST the system for normal operation after the repair. | |
| Slipping transmission | Refer to the appropriate Automatic Transmission article for the procedure. | |
| Malfunctioning hydraulic lash adjuster | INSTALL a new hydraulic lash adjuster | |
| Damaged valve guide Compression leakage at valve seat Seized valve stem |
INSTALL a new cylinder head assembly. TEST the system for normal operation after the repair. | |
| Weak or broken valve spring | INSTALL a new valve spring. TEST the system for normal operation after the repair. | |
| Worn or damaged camshaft | INSTALL a new camshaft. TEST the system for normal operation after the repair. | |
| Damaged head gasket | INSTALL a new head gasket. TEST the system for normal operation after the repair. | |
| Cracked or distorted cylinder head | INSTALL a new cylinder head assembly. TEST the system for normal operation after the repair. | |
| Damaged, worn or sticking piston ring(s) | INSTALL a new piston ring(s). TEST the system for normal operation after the repair. | |
| Worn or damaged piston | INSTALL a new piston and piston pin. TEST the system for normal operation after the repair. | |
| Engine emits excessive black smoke (black/blue/white) | Clogged Air Cleaner (ACL) element | INSTALL a new ACL element. TEST the system for normal operation after the repair. |
| Incorrect type or grade of oil | DRAIN and FILL with specified oil. | |
| Engine wear (piston rings, valve guides) | REPAIR as necessary. TEST the system for normal operation after the repair. | |
| Plugged crankcase ventilation system | Visually INSPECT the crankcase ventilation system. | |
| Oil in coolant | Leaking head gasket | INSTALL an new head gasket. INSTALL new engine components as necessary. Refer to the appropriate Engine article for the procedure. TEST the system for normal operation after the repair. |
| Leaking oil cooler | INSPECT the oil cooler and gasket for damage. INSTALL new components as necessary. Refer to the appropriate Engine article for the procedure. TEST the system for normal operation after the repair. | |
| Leaking oil filter adapter | INSPECT the oil filter adapter and gasket for damage. INSTALL new components as necessary. Refer to the appropriate Engine article for the procedure. TEST the system for normal operation after the repair. | |
| Damaged cylinder head | INSPECT the engine components for damage. INSTALL new components as necessary. Refer to the appropriate Engine article for the procedure. TEST the system for normal operation after the repair. | |
| Damaged cylinder block | INSPECT the engine components for damage. INSTALL new components as necessary. Refer to the appropriate Engine article for the procedure. TEST the system for normal operation after the repair. | |
| Coolant in oil | Leaking head gasket Leaking oil cooler Leaking oil filter adapter Damaged cylinder head Damaged cylinder block |
INSPECT the engine components. INSTALL new engine components as necessary. Refer to the appropriate Engine article for the procedure. TEST the system for normal operation after the repair. |