Autonatomy · 08.6 · Noise, Vibration, Harshness & Intermittent Symptoms

Training boundary: All complaints, captures, frequencies, vehicle data and outcomes in this module are fictional classroom examples. Frequency coincidence is not root-cause proof. No unsafe road reproduction, vehicle lifting, contact with moving parts, or improvised sensor attachment is authorized. Use current OEM procedures and qualified supervision for actual diagnosis.

Noise, Vibration & Evidence Explorer

Explore eight evidence categories and learn why a symptom description or a matching frequency alone does not prove the failed component.

Four Symptom-Pattern Journeys

Connect the reported condition, a safely obtained observation, a discriminating comparison, and the next evidence-based action.

Frequency & Symptom Investigation Lab

This classroom model compares a computed engine-rotation frequency and wheel-rotation frequency. The values are teaching examples, not a measured vibration trace or a diagnosis.

Frequency relationship bench

Illustrative engine speed (rpm)1800 rpm

Illustrative road speed (km/h)54 km/h

Fictional effective tire circumference (m)2.0 m

Engine rotation: rpm ÷ 60. Wheel rotation: road speed in m/s ÷ effective circumference. Neither value represents a verified vibration source, engine firing order, driveline ratio, or a usable OEM diagnostic limit. When the two computed frequencies happen to match, that is still not proof of causation.

Compare symptom patterns

Fictional report

Choose a report to compare candidate influences and safer next checks.

Fictional case

Select investigation

Evidence board — review the key findings

Choose an evidence card.

Choose a supported next step

Your reasoning (optional)

Case feedback is an educational model. It records neither a completed road test nor a verified repair.

NVH & Intermittent Diagnostic Decisions

Six fictional shop scenarios; choose an appropriate and safe next step supported by available evidence.

08.6 · Knowledge Check

Ten questions assess concepts, not the ability to diagnose or repair an actual vehicle.

Continue learning

Return to Course Player · Complaint Intake · 08.1 · Scan Data · 08.3 · Complaint Investigation · 08.5

Use the fictional scenarios to plan which observations and approved tests would establish a cause. A completed online exercise is not hands-on competency.