Why Does My Drill Smell Like It’s Burning?

If you’re into DIY projects or like to fix things, you’ve probably had a drill in your toolkit for quite a while now. And while you may know exactly how to use your drill to get the best results (you’ve got that pilot hole thing down), there are a few little-known ins and outs that you may not have read in the manual.

If your drill smells like it’s burning, one of three things is likely happening.

  1. The motor is overheating
  2. Battery is shorting
  3. Parts are melting

Why Does My Drill Smell Like It's Burning?

That last one sounds scary… and for good reason. If your drill smells like smoke, you’re going to want to stop drilling right away and read the rest of this post to figure out what to do next.

Let’s explore each scenario to see what’s going on with that drill of yours.

Drill Motor Overheating

If your cordless drill smells like it’s on fire, the motor overheating is the most likely culprit. This is why we’re going to spend the most time exploring this scenario.

How to Know if Your Drill is Overheating

There are quite a few factors that can contribute to a drill overheating. If your drill has been running for a long time, it’s likely to overheat. If this is the case, you’ll sense a burning smell and the drill will become hot to the touch.

If it’s a well-loved drill and you’ve only been using it for a few minutes before you smell burning, it could be overheating for the following reasons:

  1. The drill bit is blunt — Let the drill cool down and check the bit to see if it needs to be replaced or sharpened.
  2. Something is blocking the air vents — if your drill has air vents, they may be getting blocked out by dust (or even by your hands). Locate the vents and make sure they’re clear.
  3. Worn brushes — If you’re using a brushed drill, it can overheat even after a few minutes of use when the brushes have been worn down. Your drill may even create some sparks. If you think this is the case, let the drill cool down and either replace the brushes yourself or take it to an appliance repair shop to have someone do it for you. Most people replace brushes themselves because they’re quite easy to replace.
  4. The drill has expired — If the drill has had a long life and gotten lots of use, the motor may actually be dead. And in this case, the best thing you can do is replace the drill. You may find that your drill overheats faster and faster each time you use it. And if you can’t identify any other problems, the motor might be on its way out.
  5. You’re applying too much pressure — If you’re putting too much pressure on the drill, you might be damaging the drill bit. This can cause the motor to overheat and lead to a burning smell. When you drill, use a slow speed and apply firm pressure. The harder you squeeze the trigger, the faster the bit will spin.

How to Prevent Your Drill From Overheating

One of the best ways you can prevent your drill from overheating is to use cutting oil.

Cutting oil is a lubricant that will reduce friction and thus heat buildup within the drill.

And when you use cutting oil, not only can you prevent overheating, but you can also extend the life of your drill.

The following are types of cutting oils you can use:

  • Liquids (synthetic, semi-synthetic, mineral)
  • Pastes or gels
  • Carbon dioxide coolants
  • Compressed air
  • Aerosols

Drill Battery Short Circuit

If it smells like your drill is burning, it’s possible that the battery is short-circuiting. But you should know that this isn’t the most likely scenario because most drill batteries will shut down instead of heat up when they short circuit.

There are three types of batteries used in cordless drills: nickel-cadmium (NiCd), nickel-metal hydride (NiMH), and lithium-ion (Li-ion).

Most cordless drills sold today feature a lithium-ion (Li-ion) battery and this type of battery will simply power down in most cases of a short-circuit.

But if the battery has a defect to the electrochemical cell, the battery won’t power down and it will continue rising in temperature.

In these defective batteries, nothing can stop the process once it’s been triggered, so if you think it’s the battery, put the drill down in a safe space away from anything flammable. Fortunately, this is a very rare occurrence.

Under normal circumstances, a lithium-ion battery will simply power down when a short circuit occurs.

If, however, a defect is inherent to the electrochemical cell, such as in contamination caused by microscopic metal particles, this anomaly will go undetected.

Nor can the safety circuit stop the disintegration once the cell is in thermal runaway mode. Nothing can stop it once triggered.

If you have a nickel-cadmium or nickel-metal hydride battery in your cordless drill, you can check the battery’s health with a voltmeter.

Simply charge the battery and then check the voltage. If the voltmeter shows a higher number than the drill’s voltage, the battery is short-circuiting or not properly connected.

Drill Parts are Melting

There are many reasons why your drill might begin to smell like its burning, and one reason is that it actually is.

If you continue using your drill while you’re smelling that burning smell or if you’re applying way too much pressure, you might melt the plastic housing of the drill, and this will definitely heat things up and give you that burnt rubber smoke.

You’ll find that cheaper models are more prone to experiencing that plastic burn that comes with overuse. This is why it’s important to choose your drill wisely.

There are some great models you can buy on a budget, but there are others that are made of cheap materials and can break down (or melt) easily.

And if you’re planning to use your drill often, you’re going to want to invest in a brand and model that’s built to last.

As we’ve seen there are quite a few reasons why your drill might be giving off a burnt smell, and the solutions can vary from letting it rest to replacing your drill.

Regardless of why your drill smells like it’s burning, let it rest and cool down before you investigate further.

Hi there! My name is Jack and I write for ToolsOwner. I have a passion for everything related to tools and DIY projects around the house. You often find me in my workshop working on new projects.