Expert advice: how to tell if your car has suspension trouble

The suspension on our cars is a very hard-working piece of kit. And it’s one we take for granted - until we experience suspension trouble. While we’re driving forwards, the suspension is constantly in motion too, coping with undulations in the road surface and other forces on the car.

It’s the suspension that keeps the car’s road wheels in touch with the ground when we go round corners. And it’s the suspension that helps to insulate the driver and passengers from the outside.

Unsurprisingly with something that’s so busy, cars can suffer suspension trouble. And the number of potholes on our roads seem to be making suspension trouble more likely. Read on to discover how to diagnose it.

Signs of suspension damage

The first indication of any trouble with suspension will probably come from an unusual noise. There’ll be a knocking, creaking or clanking from under the car. In extreme cases, your car might not want to drive in a straight line without you constantly making adjustments with the steering wheel.

Why it helps to identify trouble

The trouble with suspension noise is it’s unlikely to be a consistent thing. In the past I’ve had problems with car suspension that’s only shown itself going over speed humps. And then they’ve had to be speed humps of a certain height!

The quickest way for a garage to identify the fault is if you can show or tell them when a noise happens or give them a clue which side the noise is coming from and when.

Why you should get it fixed

When a part of your suspension fails, the car is highly unlikely to collapse onto the road. But if a suspension part does fail, it will put greater strain on other components. Although these might pick up the slack in the short term, it will prompt increased wear.

What’s more, suspension is viewed as an important safety component. If there are problems with it, your car will fail its MOT test.

What might suspension trouble be?

Different noises mean different faults. A knocking sound when going over bumps can indicate a problem with the suspension struts. There might be a clanking sound of metal hitting metal when you go over bumps. This could show the rubber bushes that join parts of the suspension have failed.

Alternatively the clanking noise might get faster the quicker the car is going. This might be a wheel bearing, brake rotor or even a drive shaft. Whatever it is, a professional should check it out.

A creaking sound from under the car when you go over an undulation such as a speed hump could indicate worn suspension bushes. And while you’re listening for noises, think about the ride. Is it less forgiving and perhaps bumpier than usual?

How to diagnose a fault?

Take your car for a drive, turn off the radio and open the windows. You’re listening for unusual noises and the conditions they happen in. For example, the noise might only happen when you turn the steering to the right.

When you get home, park the car safely on a flat surface and make sure the parking brake is on. First look at the car. Is it sagging on one side or corner? Then push down on the corner of the car you suspect might be suffering suspension trouble. They should rise up and resume their natural position without bouncing more than two or three times.

If you think that one corner isn’t behaving as it should, have a look beneath the car. The shock absorbers contain a fluid that helps them to damp out bumps. This fluid can leak out so if the shock absorber and springs are covered in a fluid, that’s probably what’s happened.

Get it checked by a professional

Whatever you think is wrong with your suspension, it’s important that you get it checked by a professional as quickly as possible. The information you’ve gleaned will help them. But they will be able to tell you exactly what the problem is and more importantly, how serious it is.

John Price is part of Green Flag's team of automotive technical support engineers