Coils springs are integral to your car's suspension system. Your vehicle has four coil springs - one for each wheel. They are designed to absorb the impact of driving over rough terrain, and also help keep your vehicle at the correct height.
If one of your coil springs breaks, your vehicle will sit at an angle, with the lower corner over where the broken spring coil is. A broken coil spring will mean pressure on the tyres is uneven, causing the affected tyre to wear out more quickly on one side. And if the coil falls out of the vehicle it obviously creates a hazard for other road users.
If your car has a broken coil spring you'll probably hear clunking, knocking noises when you drive over rough or uneven ground. A broken coil causes mis-alignment, meaning your car's suspension angles of travel are altered, causing components to scrape or knock against each other. Your vehicle may sway or bounce more than usual.
A visual inspection of your car will likely show one corner is lower than the others. If you're unsure, use a tape measure to see how far each wheel arch is off the ground.
No, you should not drive with a broken coil spring. You should get it fixed as soon as possible. Some drivers may decide to drive on a broken spring coil in order to reach a garage or home. However, the ride is likely to be rough and controlling the car in an emergency will be more difficult. A broken coil spring will put extra pressure on the adjacent shock absorber, and may cause serious damage to it if you drive the car in that condition.
Coil springs are covered in a flexible plastic coating to help protect the metal from corrosion. However, over time, with constant compression and being hit by stones from the road, this coating can get damaged, allowing rust to form on the coil. Once this happens, the coil can weaken and potentially break. Driving over rough terrain regularly will make a breakage more likely.
Wheel imbalances can cause your suspension to wear out unevenly, potentially leading to a broken coil. A flat or blown tyre meanwhile can put huge pressure on your suspension system and can cause a coil to break. A broken coil could also cause damage to your steering and braking systems.
If a strut - which usually comprises a shock absorber and spring - leaks hydraulic fluid, it won’t work effectively, placing more pressure on the adjacent coil, increasing the chances of a break. Additional noise when driving over dips and bumps could mean you have a hydraulic fluid leak. Lower hydraulic pressure could mean springs connect with other suspension components, causing damage to brake lines or even the exhaust system.
The cost of a coil spring depends on the make and model of your car. £50 per spring is a rough guide price. If you need to replace one spring it's advisable to replace the one on the other side. It's also a good idea to have all your coil springs inspected for damage.