Noise, Vibration And Harshness

Where The Shake Lives

Vibration through the steering wheel alone usually means the fronts: balance, a bent rim or a tyre with a flat spot. Shake through the whole body brings the rears in as well. Loose wheel nuts are still on the list. Confirm pressures and that you are not mixing tyre constructions before you buy dampers.

Driveline And AWD

• Click or knock on full lock at walking pace: Outer CV joint, often after a torn gaiter lost its grease.
• Shudder on take-off or under load: Inner CV or a bent shaft.
• Rising drone around 40 to 60 mph on AWD: Transfer case and viscous coupling wear; fluid type is routinely got wrong (see A-112).

Engine Bay Sounds

• Whistle or wheeze: Manifold gasket, exhaust joint, vacuum hose, or a head gasket starting to blow.
• Tap or rattle: Valve gear, or an ancillary (pump, alternator) with a bearing on the way out. A belt chirp changes with load and damp.
• Heavy knock: Big-end knock often eases slightly under load; main bearing rumble usually worsens under load. Piston slap is worst from cold. Stop and investigate a new heavy knock.

Suspension Harshness

Pitch and roll that feel new point at dampers, broken springs or a tired anti-roll bar drop link. Wander and general instability want tracking, bushes and tyre condition before a steering rack. Exhaust hangers that let a silencer touch the body fake a chassis rattle over every bump.