Spark Plug Replacement Cost UK, Failure Symptoms & Service Guide
Spark plugs are essential for igniting the fuel-air mixture inside your engine. Worn or faulty plugs can cause misfires, rough idling, poor acceleration, and reduced fuel economy. Over time, carbon build-up, erosion, or heat damage can reduce their performance.
This page breaks down the typical spark plug replacement costs in the UK for 2025, along with how often they should be changed, and the signs that yours may need replacing. Whether you’re running a 3-cylinder hatchback or a performance petrol engine, we provide realistic pricing from independent garages and main dealers.
You’ll also find information about the difference between standard plugs, iridium/platinum plugs, and whether you should replace ignition coils at the same time. We cover both DIY-friendly jobs and those that require a mechanic due to tight engine access.
Use the articles below to understand when a spark plug service is due, compare part and labour costs, and keep your engine running at peak efficiency without overpaying for unnecessary work.
