Upper end engine noise
Common sources of upper end engine noise (ticking, knocking or rattle) include the fuel injectors, camshaft phaser sprocket(s), camshaft(s) and valve train. Upper end engine noise can be determined using the EngineEAR/ChassisEAR or stethoscope on the valve cover bolts. If the noise is loudest from the valve cover bolts, then the noise is upper end. The EngineEAR/ChassisEAR or stethoscope can be used to further isolate the noise to the specific cylinder bank and cylinder. Removal of the valve covers will be required to pinpoint the source of the noise.
- Fuel Injector Noise A common source of an engine ticking noise can be related to the fuel injector(s). This is normal engine noise that can be verified by listening to another vehicle. If the injector noise is excessive or irregular, use the EngineEAR/ChassisEAR or stethoscope to isolate the noise to a specific fuel injector.
- Camshaft Phaser and Sprocket Noise [Variable Camshaft Timing (VCT) Engines Only] The camshaft phaser and sprocket may emit a light knock in normal operation and is audible only at idle speed, with a hot engine (gear selector in park/neutral). If the camshaft phaser and sprocket noise is excessive or irregular, use the EngineEAR/ChassisEAR or stethoscope to isolate the noise to the LH or RH cylinder head. This normal noise is not prevalent at cold temperature, the engine may require a cold soak overnight for a full diagnosis to effectively be made at hot idle.
- Valve Train Lash adjusters can make an engine ticking or tapping noise noticeable at any engine RPM or temperature and is audible through the wheel well or an open hood. However, with the hood down, lash adjuster noise can be heard as a light tapping noise through the wheel well and is considered normal. The EngineEAR/ChassisEAR or stethoscope can be used to further isolate the noise to the specific cylinder bank and cylinder, some disassembly of the engine may be required to inspect for damage or wear.
Lower end engine noise
A common source of lower end engine noise (ticking or knocking) include the crankshaft, connecting rod(s) and bearings. Lower end noises can be determined by using the oil pan or cylinder block lug bosses. If the noise is loudest from these areas then the noise is lower end. If an engine noise is isolated to the lower end, some disassembly of the engine may be required to inspect for damage or wear.
Front of engine noise
A common source of noise from the front of the engine (squeal, chirp, whine or hoot) is the Front End Accessory Drive (FEAD) components. To isolate FEAD noise, carry out the Engine Accessory Test, refer to NOISE, VIBRATION & HARSHNESS .
Some other noises from the front of the engine (ticking, tapping or rattle) may be internal to the engine. Use the EngineEAR/ChassisEAR or stethoscope on the engine front cover to determine if the noise is internal to the engine. Removal of the engine front cover may be necessary to inspect internal engine components.
Rear of engine noise
A common source of noise from the rear of the engine (knocking) is the flywheel/flexplate. Inspection of the flywheel/flexplate will be necessary.
- 14. After localizing the noise, note the characteristics of the noise, including type of noise, frequency and conditions when the noise occurs and GO to «SYMPTOM CHART - ENGINE NVH»(ref-364043-S35856745712010062700000) .