How to Safely Spray Peppermint Oil On Your Engine To Deter Rodents

Some people use peppermint oil to repel mice and other rodents. Can you spray peppermint oil on a car engine? How effective is it?

I have had problems with mice getting inside my car before, including getting into my engine’s airbox. 

I put peppermint oil on my engine and shined bright light at my front two wheels to deter the mice. Mice avoid bright lights and won’t climb up the wheel into the car if you shine a bright light on them. 

Why Would You Spray Peppermint Oil On a Car Engine?

Peppermint oil can keep mice away from your car. Things like peppermint oil, cayenne pepper, and dog hair make rodents avoid the area. 

There are also many other ways to keep rodents away, including ultrasonic devices that emit sounds that rodents can hear but humans can’t. 

Why Do You Need to Keep Rodents Away from Your Car?

Rodents can damage vehicles just as they can damage homes. Any of the following animals can enter people’s homes and damage people’s property:

• Squirrels
• Gophers
• Rats
• Mice 
• Skunks
• Moles 
• Raccoons

A lot of the damage these animals do to homes also happens to vehicles. For example, an animal can chew on and damage the electrical wiring in a home or in a vehicle. 

Blocking Your Engine Intake

A rodent might store acorns in your engine intake, or put nest material there. Mice hate the smell of many common things, such as pine sol, red pepper, Irish spring soap, and peppermint oil. 

Mice Can Enter Your Airbox

Mice are small and can squeeze through smaller spaces than you would expect. A hole more than a little bigger than a mouse’s skull is big enough for a mouse to squeeze through. 

A mouse can therefore go from your engine compartment to your engine’s airbox by squeezing through small holes or vents.

Is Peppermint Oil Safe?

Yes, peppermint oil is safe to put under the hood of your car. Peppermint smells good to humans but repels rodents. All of the chemicals in peppermint oil are harmless. 

Put some peppermint oil mixed with water in a spray bottle and use it to keep rodents away from your engine. 

Don’t worry about causing water damage to your engine.  You can even spray your car engine with a water hose and it’ll still be fine.

Why Do Rats Hate Mint?

Peppermint irritates a rat’s nostrils, which bothers them enough that rats avoid anywhere that smells like peppermint. They also hate the smell. 

Other Problems Rodents Cause

Sometimes, rodents can do real damage to your car. They will chew through hoses and wires, leading to leaks and malfunctions. 

Sometimes, running a car after rats have damaged it will do more serious damage. 

Rodents are particularly likely to damage cars that are stored for a long time in cold weather without anyone running them. 

One of the worst things for rodents to damage is the engine wiring case. If they wreck that, it will cost thousands of dollars to fix. 

It is also unsafe to drive a car with exposed wires. Rodents can build nests inside cars, which can damage many things. The air filter may get clogged with nesting materials. 

Ways to Deter Rodents

Leave the Hood Up to Scare Rodents Away

Surprisingly, you can deter rodents by leaving your car hood up at night. A rodent wants to hide somewhere dark where a predator can’t see it.

This makes a car with the hood down a good place, but not a car with the hood up. With the hood up, the rodent is not in complete darkness and is not hidden. 

Use Traps

Set rat traps and use something like peanut butter as bait. Rats enter your car most commonly by climbing up the wheel and entering from below. Put the traps near the two front wheels for the best results.

Use Light to Deter Rats

Again, climbing up your front tires is the usual way for rats to enter your car. Rodents usually avoid light when moving around at night.

If there is a bright light on your tires, a rodent won’t want to climb up the tire. 

Close Your Garage Door

If you have a garage, close the door to keep rodents out. Not everyone has a garage, but take advantage of it if you do. A pet cat can protect your car from rodents if you have a garage. 

Try Ultrasonic Devices

There are many sounds that are too low or too high pitched for humans to hear but are heard by many animals. Some ultrasonic (too deep pitched for the human ear) sounds repel rodents. 

Ultrasonic devices work best if you put more than one of them near or in your car. Make sure you buy the right products because some companies sell nearly useless devices. 

Pine Tree Air Fresheners

I know someone who tried putting pine tree air fresheners under the hood of their car. This apparently works – mice hate the smell. 

Call a Pest Control Company

If you can’t fix the problem yourself, call a pest control company. If rodents have infested your house and are going from your home to your garage to your car, this may be a bigger problem than you can deal with alone. 

Key Takeaways

• Yes, it is completely safe to put peppermint oil on your engine. Peppermint oil is harmless to humans. It does not contain any unhealthy chemicals. 
• People use peppermint oil to deter rodents. While it smells good to humans, mice and rats avoid it. It isn’t necessarily the best way to deter rodents, but it does work. 
• People also use light, dog hair, human hair, cayenne pepper, and traps to keep rodents away from their homes and cars. If the problem is too big to solve yourself, call a pest control company. 
• If rodents get inside your car, they can sneak into your car’s airbox and reduce or prevent air intake. They usually sneak in by climbing up the wheels. You can prevent this by putting traps near the front wheels or shining a bright light on them.