Noisy and Bumpy Suspension? Know the Cause & Fix

Key Highlights:

• Beyond comfort, a car suspension system is primarily engineered to ensure the wheels remain in contact with the road surface.
• What begins as a slight rattle could lead to total suspension failure if left uninspected.
• Some noises may be false indicators since unrelated components in the vicinity of the suspension system can also wear or loosen with time.

Components of an Automotive Suspension

To understand car suspension noises, it is helpful to know the main parts of the system. Each of these parts can wear out or become damaged over time, resulting in various types of noise.

• Springs: absorb energy from bumps and dips, ensuring a softer ride.
• Shock absorbers or dampers: control the movement of the springs, preventing the car from bouncing too much.
• Struts: integrate the spring and damper units into a single assembly, providing structural support alongside shock absorption.
• Control arms: connect the wheels to the frame, allowing them to move up and down.
• Ball joints: pivot points between the control arms and the wheels.
• Bushings: rubber or polyurethane mounts that reduce vibrations and noise at joints
• Stabiliser bar or anti-roll bar: reduces body roll when the car corners at high speeds.

Harmful Suspension Noises and Causes

Abnormal noises from the suspension are more than just annoying. They can be early warnings of parts that are failing. Ignoring them can lead to uncomfortable driving conditions, higher repair costs or even accidents as the driver may not be able to regain control of the car, once lost. Knowing what each noise means helps owners act quickly before issues grow worse.

Knocking Sounds

A knocking sound often means something is loose or worn out. Knocking noises should never be ignored, as they often point to parts that may fail if not repaired soon.

• Worn ball joints: These can knock when turning or going over bumps. If left unchecked, they can affect steering capabilities.
• Loose control arms: If the bushings or bolts are worn, the arm can move around and produce knocking.
• Damaged shock absorbers: If a shock absorber is leaking or its mounting bolts are loose, it can produce a knocking noise with even the slightest road undulation, such as a slow traverse over a speed bump.

Bumping or Thudding Sounds

A bumping or heavy thud usually happens when driving over uneven ground. This type of noise can quickly affect ride comfort and damage other components if not fixed. Some thuds are also inherent depending on the engineering behind the suspension system.

• Broken or weak springs: Springs that have cracked or sagged will bottom out, causing a hard thud as the suspension hits its limit.
• Failed dampers: If shock absorbers no longer dampen movement, the suspension can hit the bump stops with a loud thud.
• Damaged bump stops: These rubber parts prevent metal-on-metal contact. If they are worn or missing, the suspension will make a bumping sound upon impacts, as well as squeaks and vibrations on poorly paved roads.

Squeaking or Creaking

Squeaks are high-pitched noises often linked to dry or worn parts. Squeaking is often less serious than knocking, but it signals parts that are nearing the end of their life.

• Worn bushings: Rubber bushings can dry out, crack, or wear over time, leading to squeaking.
• Dry ball joints: Without enough lubrication, ball joints can squeak each time the wheel moves about them.
• Old shock absorbers: As shocks wear out, their seals may fail, leading to squeals alongside other abnormal sounds.

Rattling

A rattle often points to something loose. Rattles may start mildly but grow louder as the looseness increases. Sometimes, loose components unrelated to the suspension system but located in the vicinity may send incorrect signals, unless they are correctly inspected.

• Loose stabiliser bar links: Small rods connect the stabiliser bar to the suspension. When their joints wear, they rattle whilst driving over rough surfaces.
• Loose bolts or mounts: These contribute to the most common reason for rattling in any mechanical component assembly.
• Exhaust contact: Sometimes what sounds like suspension rattle can be the exhaust system hitting the underbody (also due to loose fitting).

Clunking while Turning

If the car makes a clunking noise while turning, it is often related to the steering and suspension links.

• Worn CV joints: ‘Constant Velocity’ joints in front-wheel-drive cars can clunk if the protective boot splits and grease leaks out.
• Damaged ball joints: These can also clunk while steering over bumpy roads.
• Broken control arm bushings: This issue affects handling and can be dangerous if left unsolved.

Diagnosing Bad Car Suspension Noises

It is not always easy to know the exact source of a bad car suspension noise. Some noises may originate from other areas, such as the brakes, tyres or steering system. Hence, a comprehensive check is always recommended. Technicians often do the following checks:

• Inspect the suspension visually for worn or broken parts, often when the car is on lifts.
• Push down on each corner of the car to test if the shocks rebound properly.
• Listen carefully while driving at different speeds and on different surfaces.
• Lift the car and move the wheels by hand to feel for looseness in ball joints or bearings.

How to Prevent Bad Car Suspension Noises

While wear and tear are natural, there are ways to reduce the chances of early suspension noise and further compromises. Here are some steps a driver can take:

• Drive carefully over speed bumps and potholes.
• Check and tighten loose suspension components at the recommended intervals.
• Inspect bushings and ball joints regularly.
• Keep the tyres properly inflated to reduce stress on suspension parts.
• Get the wheels aligned and balanced at regular intervals.

Regular checks, careful driving and timely maintenance will keep the suspension components in good condition for longer. Beyond comfort, safety cannot be compromised since it’s ultimately your car’s suspension that tries the most to maintain road contact.

FAQs

1. Can suspension noises affect vehicle safety?
Yes. A failing suspension part can reduce stability, braking efficiency and control, making the car unsafe.

2. Are grinding noises related to suspension?
Yes, in most cases. Metal-to-metal contact in ball joints or strut mounts can create grinding, which should be repaired immediately.

3. Can wheel alignment fix suspension noise?
Not always. Alignment improves handling and tyre wear, but cannot fix noises caused by worn or broken suspension parts.

4. How long can I drive with a noisy suspension?
It is not safe to ignore. Driving with bad suspension may cause further damage and reduce vehicle safety.

5. Can I fix suspension noises myself?
Minor issues like tightening bolts or greasing bushings may be DIY-friendly, but major repairs usually require a qualified technician with the right tooling.