DIY car maintenance: How to clean car engine bay

Nov 24, 2020 4 min read
DIY car maintenance: How to clean car engine bay

Cleaning your car's engine is as necessary as cleaning the exteriors and interiors of your car. Regular cleaning can prevent a thick accumulation of dirt and grease on the engine.

The more you drive your car, the more the exteriors of your engine get dirty. To avoid accumulation of thick dirt, greases, and other particles; you need to clean your car engine bay on a regular basis.

Let us find out how to clean the car engine bay through a step by step process.

Select a suitable place to clean the car engine bay

The grime from the engine bay of a vehicle is full of environmentally toxic materials. These materials must not be allowed into the sewage system, both wet and dry. So we will explain how to collect and manage these substances at a hazardous disposal site if you decide to clean your engine bay at home.

You can go to a car wash service if you don't wish to clean your engine bay at home. These facilities are required by law to recover, reuse, and clean the water in a closed system. They filter and collect dangerous substances for safe disposal. If you're cleaning your engine bay on a car washing service, pay more attention to the water pressure from the water tube to avoid high pressure from damaging the components of the engine.

Cool down the engine

Spraying water on a hot engine might crack few parts. Hot engine parts can also burn your hands. You can quickly cool down the engine by first sprinkling water on the bonnet and radiator of the car before opening the engine hood.

Caps and cover tightening

Check for all caps, cloths, and dipsticks to make sure they are well seated or sealed. You will not want the water to seep into the openings and damage internal components of the engine and other systems.

Electrical and filter protection

Turn off battery terminals or if possible, remove the battery. However, it is worth nothing that in most new vehicles, if the battery is disconnected without backup power, you will lose your seat position and other electronic information or settings.

To securely cover the electric parts under the hood, use plastic and electrical tape. The alternator, fuse box, dispenser cap, spark plugs, and coil packs all can be damaged by the penetration of the water. Cover exposed, damaging filters too.


To keep you eyes and mouth safe against floating scraps, wear security glasses and a dust mask. Gloves protect your hands from harsh cleansing agents and stains. Put a drip tray beneath the engine and absorb pads down to the side of the chamber when you work at home to collect all the toxins.

Dry cleaning

Start cleaning by removing the dry material. Vacuum clean all of the dust and use brushes to break up and loosen the accumulation. The plastic and synthetic surfaces can be fiber brushed, while the metal surfaces are the best for a wire brush. Continue to collect all dirt with the vacuum. If you are at home, remove any materials you collect from the drip tray and vacuum.

Spray the engine bay

To moisten the exposed surfaces of the engine bay, use warm water in a spray bottle. This step aids the degreaser to operate evenly and prevents it from drying up on the engine. The use of a spray bottle allows for further application control and minimizes the water required for cleaning. The warm water also prevents warping and cracking of parts that can still be hot.


Apply degreaser on all exposed surfaces in the engine bay using spray bottles with greater attention to the regions that have accumulated grime. Let the degreaser work for 10 minutes. Meanwhile, empty the vacuum and convert it from dry to wet. Now, your contaminated fluid can be collected with it.

Collect and rinse

To rinse the engine bay, use a low-pressure spray. This should not be a problem at home, but self-service car wash water guns have high water pressure. When you use it, you have to be careful not to pull a high-pressure trigger while cleaning the engine bay.

At home, you can control the runoff with the absorbing pads and shop vacuum. Use the vacuum in the store after rinsing to collect water in the engine bay from the cavities and gaps. Remove the entire bay from the degreaser with a towel, and re-clean everywhere you missed or needed additional attention. Rinse those areas with spray bottle water again and wipe the cloth.

Collect the collected water from the drip tray and vacuum excess water in the pads.

Dry completely

Use a leaf blower to aid in drying the engine bay. After drying, keep the engine as it is so that it can become moisture-free on its own.

Hand clean the electric parts

Remove the plastic protection on the electrical components by hand and clean them through brush and a damp cloth. After the cleaning of these elements, you can reinstall the battery.

Start the engine

Start the engine and allow it to come to operating temperature to clear out any remaining humidity. As a final step, transport the soiled container bag and the pool of contaminated water to a hazardous waste disposal site if you've been working at home.

Thus, we have seen in detail, the complete step by step process of cleaning the engine bay. You can also follow the step by step process mentioned and clean your car’s engine bay yourself. In case you find that it is difficult to clean your car engine bay yourself, you can go for professional help.

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