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How to Get Rid of Rats in Your Car Engine: A Complete Guide [2023]

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how to get rid of rats in car engine

Rats are some of the craftiest nuisance pests you can encounter. Smart, capable of eating almost anything, and able to live almost anywhere, we see them in houses, factories, offices, and more.

One of the most surprising places we tend to see them, though, is in the engines of our cars.

If the thought of opening your hood to find a rat sounds horrifying, just imagine all the damage they can do to your engine while they’re in there!

Don’t worry, though. You don’t have to resign yourself to rats in your engine forever.

In this guide, we’ll help you learn how to get rid of rats living in your car engine by sharing our top field-tested techniques.

What You Need to Get Rid of Rats in a Car Engine

Before you begin, gather these supplies:

  • Full Face Respirator. Rats carry hantavirus, which can cause hantavirus pulmonary syndrome (HPS) in humans who encounter infected rat feces or urine. As such, it’s critical to wear personal protective equipment (PPE) when getting rid of rats. A full-face respirator will protect you from inhaling airborne viruses and other rat-borne irritants.
  • Gloves. Wear gloves like these to protect your hands from injury and avoid contact with rat feces, urine, or nesting material during removal.
  • Rodent Repellent Spray. This outdoor rodent repellent spray is 100% natural and designed to keep rats from re-entering your car engine once you’ve cleaned it out.
  • Weighted Car Cover. Create a rodent-proof barrier around your car with a weighted car cover. The cover sits flush with the ground to create a rodent-resistant barrier that rats can’t penetrate.
  • T Rex Snap Traps. Setting rat traps around your yard, garage, and property will reduce rat populations and prevent re-infestation. Zachary Smith, the owner of Pest Dude and a licensed pest removal professional, relies on these T-Rex plastic rat traps for two reasons. First, they’re easy to set, and second, they have a superior design that allows them to be easily triggered by foraging rats. We recommend baiting them with peanut butter, Snickers bars, beef jerky, cheese whiz, or bacon for best results. If you want to try a different trap, check out our guide on the best rat traps.

How to Get Rid of Rats in Your Car Engine

Ready to send rats packing? Follow these steps to remove rats from your car engine:

1. Prepare the car

Open the car’s hood, doors, and trunk to let the vehicle air out for about 20 minutes before you begin.

This helps clear out dangerous airborne contaminants and reduces your chance of encountering hantavirus.

2. Inspect the vehicle

Before evicting rats and their nests, you must figure out where they live. As such, the next step is to conduct a thorough inspection of the vehicle’s interior and engine.

Remove the cables from the battery to avoid shock before inspecting the engine, including all air intakes and filters. Identify and make a note of all nests and areas of rat activity.

Be sure to wear rubber or plastic gloves, a respirator, and a long-sleeve shirt as you complete this step.

3. Disinfect

Once you’ve pinpointed living or dead rodents, nesting materials, and rodent waste, gather your cleaning supplies to clean and disinfect the engine.

Here’s the process the CDC recommends:

  • Spray all affected areas with a CDC-approved disinfectant until they’re thoroughly soaked. Allow the disinfectant to sit for 5 minutes.
  • Wearing rubber or plastic gloves, use a paper towel to pick up and remove all nesting materials. Dispose of them in a sealed plastic bag. If nesting materials are present in the air intake system, remove the air filter and the nesting materials. Discard both in the garbage before inserting a clean replacement filter and closing the air intake unit.
  • Once you’ve sprayed disinfectant on the affected areas, you can use a shop vac to remove rodent urine, droppings, and nest material.
  • Once you’ve removed all the nesting materials, clean the rest of the affected area with additional disinfectant.
  • Allow the area to dry thoroughly for 60-90 minutes.
  • Once the engine is dry, reconnect the battery.
  • When you’ve finished disinfecting the area, wash your gloved hands with hot, soapy water. Remove the clean gloves and wash your bare hands with hot, soapy water.

4. Finish with a non-flammable repellent

commercial rat repellent

Once you’ve disinfected your engine and removed all nesting materials, spray the engine with a non-flammable rodent repellent like this one or apply a repellent gel (we like this one).

The repellent will make your engine unattractive to rodents and help deter them from returning.

5. Clean up your yard

Next, turn your attention to the space around your car. We recommend cleaning up your yard to make it unattractive to rodents.

Here are a few tips:

  • Clean up all debris piles and anything that could provide shelter to rats, including piles of recycling or cardboard boxes, old appliances, and wood piles.
  • Remove rat food sources, including fruits, nuts, acorns, pet food, and human scraps. If you have snails in your yard, consider investing in a professional snail treatment since these mollusks are a rat’s favorite food.
  • Introduce natural predators to your yard by building an owl box or letting pet dogs and cats out into the yard more frequently.

Here’s another tip from the Pest Dude:

“Apply heavy and repeated repellent spray to the engine bay, as well as trapping and baiting all around the property to reduce the rats.

Leave the hood open to let more daylight in. Rats hate daylight!

The problem will go away with regular preventative repellent spray and population reduction.” – Zachary Smith, “The Pest Dude”

How to Keep Rats Out of Your Car

car maintenance inspection

Now that you’ve dealt with your rat infestation, keep the pests from coming back with these tips:

  • Keep your car covered with a weighted cover like this one, especially if you won’t be using it for an extended period.
  • Maintain your vehicle correctly – remember that rats can easily enter your vehicle’s cabin through ducts, rusted areas, and cable conduits. Have any potential access points patched or sealed by a mechanic.
  • Do not leave any kind of food or drinks in the car since they can attract rodents.
  • Re-apply rodent repellent every three months.
  • Avoid parking your car in areas known to attract rodents, like alleys near trash bins or near natural food sources, like vegetable gardens.
  • Keep your car in a closed garage whenever possible.
  • Never leave your car’s doors or windows open when the car is not in use.
  • Move parked cars regularly to deter rodent activity.

What Attracts Rats to Car Engines?

Here are the two main things that attract rats to your car’s engine:

1. Warmth

When rats enter a car engine, they’re usually looking for a safe, warm place to build a nest. Fortunately for them, car engines offer both shelter and warmth.

Rats like to live in dark, enclosed places where they can breed, nest, and raise their babies without being bothered.

As such, these pests are most likely to seek out rarely used engines. We tend to find them in cars that have been parked for long periods or cars that are parked in rat-infested areas.

2. Water

Rats need moisture to survive, and car engines are a rich source of it. Between the electrolysis component, wires, and battery, there’s a surprising amount of moisture within a car’s engine.

Additionally, the soy-based wiring used in modern cars may represent a food and moisture source for rats looking for sustenance.

What Damage do Rats Cause to Cars?


Rats will pack the cavities of your car’s engine with nesting materials like shredded paper, organic materials, and sticks. Over time, this can block critical engine components or create fire hazards.

Once they’ve created a cozy home in your engine, rats will gnaw on the wires and hoses surrounding them.

They don’t chew wires because they’re hungry: they do it to gather more nesting material or to keep their ever-growing teeth trimmed.

Unfortunately, all that gnawing can blow fuses, start fires, or even destroy your car’s engine.

“We once had a customer show us their $2800 bill from the mechanic after taking their Ford pickup in for repairs.

The rats had eaten so much insulation off the wires, there were short circuits causing the vehicle to be inoperable.” – Zachary Smith, “The Pest Dude’

Don’t let this happen to your car!

Moreover, if rats die in your engine, their decomposing bodies will create a stench that travels into your car’s cabin through the HVAC system, making your heating and air conditioning impossible or unpleasant to use.

Have Rats Nested in Your Car? We Can Help!

You don’t have to live with rats in your car engine forever. Our experienced team is here to help!

If your DIY rat removal attempts have failed, or you’ve run out of options, it’s best to contact a reputable, local pest control company in your area.

Fortunately, we have a broad network of reputable partners in your area.

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If you can find the dead rat, carefully remove it while wearing heavy-duty rubber gloves. Dispose of the rat carcass in a sealed plastic bag and place it in a trash can that gets emptied regularly. If you can’t find the rat, you may need to take your car to a mechanic for further assistance.

If rats have damaged your engine, unfortunately, the only option is to take your car to a local mechanic. They’ll be able to evaluate the extent of the damage and make repair recommendations to keep your car safe. 

Depending on where in your engine rats are nesting, they may be able to stay there while you’re driving. Alternatively, they can enter the cabin of the vehicle, making for an unwelcome surprise for the driver! The best way to prevent this is to deal with rat infestations promptly and completely, which will prevent damage to your engine and prevent them from entering the cabin with you while you drive.

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Author Bio: Zachary Smith

Zachary Smith is the founder of Zachary is a licensed pest control professional with 20+ years of hands on experience eradicating pests from homes and businesses. Zachary earned his Bachelor of Science from Cal Poly San Luis Obispo in 2002. He specializes in rodent and insect infestation management of structures and landscapes. His passion is to share his extensive knowledge with the world.

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