Nissan Qashqai Spark Plug Replacement in Walsall
This Nissan Qashqai came into us at Platinum Vehicle Services after the owner noticed it had become sluggish pulling away from junctions and was using more fuel than usual. The engine was also idling unevenly at traffic lights, which is a tell that the ignition system is not firing as cleanly as it should. The first thing we looked at was the spark plugs.
The Spark Plugs Were Worn Well Beyond the Point at Which They Should Have Been Changed
Spark plugs do one job, they produce a small electrical spark inside each cylinder to ignite the fuel and air mixture that drives the engine. When they wear, the electrode tip, which is the small metal point at the end of the plug where the spark jumps across, erodes over time. The gap between the electrode and the earth strap widens as the metal wears away, and the wider that gap becomes the harder the ignition system has to work to bridge it. On this Qashqai the electrode tips were visibly rounded and eroded rather than having the clean, sharp edges you want to see on a healthy plug. The gap on the worst of the four was around 1.4mm where the target is closer to 1.0mm. That difference sounds small but it is enough to cause misfires, particularly at low revs and under load.
Leaving Worn Spark Plugs in Place Puts the Ignition Coils Under Pressure and Repair Costs Rise Quickly
A worn plug forces the ignition coil, the component that generates the high voltage needed to create the spark, to work harder than it was designed to. Over time that added strain can cause a coil to fail. A set of four spark plugs is a relatively modest job. A set of ignition coils on top of that is a significantly more expensive repair, and a failing coil can put the engine into a reduced power mode that leaves you struggling to keep up with traffic or unable to pull onto a fast road safely. Beyond the cost, a misfiring engine is also sending unburnt fuel into the exhaust system, which can damage the catalytic converter. That is another expensive component to replace and one that is not necessary to touch if the plugs are kept on top of.
Four New Spark Plugs Fitted to the Correct Specification and the Engine Running Cleanly Before It Left Us
We fitted four new spark plugs to the manufacturer specification for this engine. Each plug was torqued to the correct setting using a torque wrench, which is a tool that measures exactly how tightly a fastener is secured, because overtightening a spark plug can crack the thread in the cylinder head and that becomes a far more involved repair. Once all four were in we started the engine and let it run up to temperature. The rough idle cleared immediately and the engine settled into a smooth, even tick at rest. We road tested the car before handing it back to confirm the hesitation on acceleration had gone.
If Your Car Is Hesitating, Idling Roughly or Drinking More Fuel Than Usual, It Is Worth Getting the Plugs Checked
Spark plugs are one of those parts that wear gradually, so the change in how your car drives tends to creep up on you. Most manufacturers recommend changing them somewhere between 30,000 and 60,000 miles depending on the plug type, but real world driving conditions mean some cars need attention sooner. If you are noticing a rough idle, a drop in fuel economy, a hesitation when you pull away, or a judder at low speed, those are the signs to act on. We cover this kind of work every week for drivers across Walsall and the surrounding areas including Bloxwich, Aldridge, Willenhall and Brownhills, and we will always tell you exactly what we find before we do anything. To book your car in or to leave us a message at any time of day, call us on 07970901354 or visit us at platinumvehicleservices.co.uk.
