Can I Drive with Bad Spark Plugs? What Happens and When to Replace Them
Driving with bad spark plugs may seem harmless at first, but it can lead to expensive engine damage. Learn the signs, risks, and when to replace them to avoid costly repairs.
When your car starts acting up in late 2025, it’s rarely just one thing. It’s usually a chain reaction—spark plugs, small but critical components that ignite fuel in your engine. Also known as ignition plugs, they’re the first link in the chain that keeps your engine running clean and smooth. If they’re worn out, your engine misfires, your fuel economy drops, and worst of all, unburned fuel floods your exhaust system, the path that carries waste gases out of your engine. This doesn’t just make your car smell bad—it can kill your catalytic converter, a costly part that’s designed to clean those gases before they leave your tailpipe. You might not notice until your car fails an emissions test, or worse, stalls on the motorway.
That’s why brake rotors, the metal discs your brake pads clamp down on to stop your car. Also known as brake discs, they’re just as vital—and just as easy to ignore until it’s too late. Worn or warped rotors don’t just make your brakes squeal. They make your pedal feel spongy, your car pull to one side, and your stopping distance longer. Driving with bad rotors isn’t just risky—it’s illegal in the UK if your brakes don’t meet minimum safety standards. And if you’re hearing grinding or feeling vibrations, you’re already past the point of a simple fix. The same goes for windshield wipers, the simple blades that keep your view clear in rain or snow. Also known as windscreen wipers, they’re often overlooked until you’re stuck in a downpour with streaks blurring your vision. Cheap wipers don’t last. Streaking, chattering, or missing spots mean they’re done. Waiting until they fail completely isn’t smart—it’s dangerous.
And then there’s the silent killer: the fuel pump, the part that pushes gasoline from your tank to your engine. Also known as fuel delivery system, it doesn’t throw error codes like a spark plug or brake sensor. Your OBD2 scanner might show a generic "fuel system lean" code, but that doesn’t mean the pump is bad—it could be a clogged filter, a bad sensor, or even dirty fuel. You need to test fuel pressure to know for sure. And while we’re on the topic of fixes, don’t fall for the myth that topping up oil solves engine trouble. Adding oil might hide a leak, but it won’t fix a worn piston ring or a cracked gasket. It just buys you time before the engine blows.
This month’s collection covers exactly these issues—what to look for, how to spot the real signs, and when to act before you’re stranded or facing a £1,000 repair bill. You’ll find real numbers on what brake rotors cost to replace, how long wiper blades actually last in UK weather, and why a code reader won’t tell you if your fuel pump is dead. No fluff. No guesswork. Just what you need to know to keep your car safe and your wallet intact.
Driving with bad spark plugs may seem harmless at first, but it can lead to expensive engine damage. Learn the signs, risks, and when to replace them to avoid costly repairs.
Driving with bad rotors is dangerous and illegal. Learn the signs, risks, and what to do if your brake rotors are worn, cracked, or warped. Don't risk your safety-replace them before it's too late.
Find out what a fair price is for windshield wipers in the UK in 2025. Learn which types offer the best value, how to avoid cheap traps, and when to buy for maximum savings.
Brake rotors typically last 30,000 to 70,000 miles, but driving habits and conditions affect their lifespan. Learn the signs of worn rotors, when to replace them, and how to extend their life for safer braking.
Find out how much radiator replacement costs for your car in the UK, including parts, labor, and hidden expenses. Learn what affects pricing and how to avoid costly mistakes.
Learn the key signs your windscreen wiper blades need replacing-streaking, squeaking, missed spots, and more. Don't wait for failure; replace them before rain season hits.
A code reader won't directly tell you if your fuel pump is bad. Learn the real symptoms, common error codes, and how to properly test fuel pressure to confirm failure.
Learn how to tell if your front or back brake pads are worn out by listening for sounds, feeling the pedal, and checking visual signs. Don't guess-know for sure before it becomes dangerous.
Faulty spark plugs cause incomplete fuel combustion, leading to unburned fuel in the exhaust. This increases emissions, damages the catalytic converter, and can cause your car to fail emissions tests. Replacing worn plugs fixes exhaust problems and saves money.
Adding oil to your car might seem like an easy fix, but it can hide serious engine problems. Learn when topping off is safe-and when it’s risking your engine.