A road spring has snapped. It's usually the bottom coil that goes, and the broken end can sit close enough to the tyre to damage it. This is one of the few suspension defects where the wording is unambiguous — there's no interpretation needed.
Wording as it commonly appears on an MOT certificate: “Coil spring fractured or broken”.
What does it mean?
A road spring has snapped. It's usually the bottom coil that goes, and the broken end can sit close enough to the tyre to damage it. This is one of the few suspension defects where the wording is unambiguous — there's no interpretation needed.
How serious is it?
Usually recorded as: Dangerous. The tester assesses the actual vehicle on the day, so your certificate is what counts.
What normally causes it?
- Corrosion pitting at the bottom of the coil where water and grit collect
- Fatigue on a high-mileage car, often triggered by a pothole
- Cheap replacement springs fitted previously
What a mechanic would check
Torch on both springs on that axle and follow every coil round, especially the bottom two. I'd check the tyre sidewall for rub marks and check the ride height side to side. If one has gone, I'd look hard at the other — they've had identical lives.
What might need replacing
- Springs replaced in pairs across that axle
- Spring seats or isolators, which are usually perished by then
- A tyre, if the broken end has been cutting into the sidewall
Can you still drive it?
Commonly recorded as Dangerous. A broken spring end can slice a tyre without warning, and the car's handling and ride height are already compromised. Don't drive it — get it recovered or repaired where it stands.
Repair cost
Springs themselves are not usually an expensive part; the labour depends on whether the strut has to come out and be compressed. Ask whether both sides are being done, because doing one is a false economy on a car of that age.
Before the retest
Suspension parts such as springs, shock absorbers and drop links are normally replaced in pairs across an axle so the car sits level and handles evenly. Any work that disturbs the steering or suspension geometry is worth following with a wheel alignment check, otherwise you can pass the retest and still wear out a new pair of tyres within months. Listen for the original knock again on a bumpy road before the retest — if it is still there, something was missed.
Retest rules
If the vehicle stays at the test centre for repair and is retested within 10 working days, a partial retest is often free; some items qualify for a free retest if you bring the car back by the end of the next working day. The exact conditions are set out on GOV.UK, so confirm with the test centre before you leave. A major or dangerous failure means the car cannot legally be driven away unless the previous MOT is still valid and nothing dangerous was recorded — check your certificate first.
Related help
More suspension failures · MOT failure decoder · Ask a mechanic about your certificate
This is general guidance from a UK mechanic, not a substitute for a physical inspection. Only the tester who inspected your vehicle can confirm what was recorded and why.