Diagnostics · Expert tip
Engine noise tells you where to look
Ticks = top end, knocks = bottom, squeals = belts/bearings.
The expert tip
- Ticking that follows RPM = valvetrain or exhaust leak
- Deep knock under load = bottom end or detonation
- Squeal on start = belt or accessory bearing
- Localize with a stethoscope before dismantling
Source: Workshop diagnostic practice
Apply tips that match your car and manual. For anything safety-critical or high-voltage, use a qualified mechanic.