Status: 09.12.2023, 05:32 a.m.
By: Simon Mones
A defective spark plug manifests itself in many ways. It's easy to see if an exchange is necessary. For the change, however, you should go to the workshop.
It's completely normal for something to break down on the car. Be it the battery that gives up the ghost or an imminent engine failure. And other components such as the alternator or the spark plugs are also not protected against defects. Depending on the manufacturer and engine, the spark plugs last around 30,000 to 60,000 kilometres. If iridium or platinum spark plugs are installed, longer replacement cycles are possible. But at some point, a change is unavoidable.
Replacing the spark plug: Fuel consumption can be a sign
As is often the case, there are signs that the time has come for a change. According to the German Press Agency (dpa), underperforming and worn spark plugs in petrol engines – diesel engines come up without them – are audibly and tangibly noticeable.
A fresh spark plug can solve many a problem. © Iamgebroker/Imago
Typical warning signs are ignition misfires, problems starting the engine or jerking when driving. In addition, lower engine power and increased fuel consumption indicate a defect. If any of these signs occur, you should visit a specialist workshop.
Replace spark plugs: Inexperienced mechanics should go to the workshop
But even a simple visual test can provide certainty. For example, spark plugs should be replaced with worn electrodes that look burned or charred. The reason for this is that the ignition spark can no longer jump properly and the engine no longer works optimally.
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However, this is not a task for inexperienced mechanics. Therefore, experts recommend visiting a specialist workshop for the exchange. This can sometimes be expensive, especially if you drive a Bugatti Veyron. However, amateurs could do too much wrong during installation and, for example, damage the thread when screwing it in. If you want to make the change yourself, you should follow the instructions of the Automobile Club Verkehr (acv):
- First of all, you need to gain access to the spark plugs. With older vehicles, this is easy, as you already have the spark plug connectors in front of you after opening the hood. In newer cars, some of the covers under which the spark plugs are hidden must first be dismantled.
- If you have access to the spark plugs, the spark plug connectors must be removed. These are each assigned to a cylinder and must be reattached to the correct place even after the change.
- Now the upper part of the spark plug is visible. Before unscrewing, it is recommended to clean the spark plug well with a hard brush. This ensures that no dirt gets into the cylinder after unscrewing the spark plug.
- In the next step, the spark plug is unscrewed with the spark plug wrench. In order not to damage the thread in the cylinder head, it is necessary to work carefully. Impurities that are in the thread can still be removed with a cloth if necessary.
- The new spark plug can now be screwed in by hand. When screwing in by hand, it is easier to determine whether the thread of the spark plug and the cylinder head fit together correctly.
- If the spark plug is firmly seated in the thread, it can be tightened with a torque wrench and the corresponding tightening torque.
- Finally, all you have to do is plug the plugs to the upper halves of the spark plugs.