There are several signs that indicate it is time to replace your coil. You should be wary of gurgling sounds coming from your device, along with a decrease in vapour production. These are all tell-tale indicators that your coil is not working at its optimal output. The most recognised sign that your coil is coming to the end of its lifespan is a burnt, acidic taste in your vape. As soon as you experience the slightest indication that your coil is burnt you need to replace it. Enduring a burnt vape can lead to unpleasant nausea and sickness. There are several reasons why your coil might be damaged.