How to Clean the Engine Bay: Dos, Don’ts, and FAQs

The engine houses your ride’s battery, engine, transmission, and other critical components that keep your vehicle running. If the engine bay is dirty, these parts might not perform efficiently, so make cleaning it part of your regular maintenance.

What Does Cleaning the Engine Bay Entail?

Cleaning the engine bay involves removing the accumulated dirt, grime, and debris in it. If you’re doing it on your own, get quality engine bay cleaners. Prepare brushes and towels as well to scrub and wipe away dirt and grease.

Engine bay cleaning also involves cleaning the area around the battery, so you must disconnect your battery and remove it before proceeding.

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: Brake parts cleaner works well for this but don’t have the engine running when you spray the cleaner. Try to get non-flammable brake parts cleaner. You’ll probably need several cans. Don’t use flammable BPC.

What to Do (and What Not to Do) When Cleaning Your Engine Bay

You can always let a professional clean your engine bay for you. However, if you’d like to do it on your own and save on the service fee, make sure you know these dos and don’ts:

Do’s

Wear Protective Gear

Always prioritize your health and safety when doing any maintenance task. Wear a protective mask, gloves, and eyewear when cleaning your engine because you might come in contact with harmful chemicals and debris.

Take Pictures Before Starting

Cleaning the engine bay involves removing, unplugging, or dismantling parts. If you’re not familiar with their arrangement, you might have trouble returning them.

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: Most people (like car dealer detailers) don’t disconnect anything, so it’s not always necessary unless there is some serious buildup under something you’re removing.

So before cleaning your engine, and if you do decide to disconnect hoses and wiring, take a picture using your phone. It will give you a great reference for when you need to return the components you removed. Take photos from different angles and, if you want to ensure you don’t forget anything, get shots every time you remove something.

Protect Electrical Components

You’re going to use water and cleaning agents, which is bad for electrical components. While most parts have some kind of protective covering that keeps water and other contaminants out, it never hurts to take extra measures to secure them.

Cover exposed electrical parts with plastic bags. Secure them with zip ties to keep moisture from coming in contact with the component.

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: This isn’t necessary if you’re using the non-flammable brake parts cleaner but don’t hit the connectors with a lot of high liquid pressure no matter what you’re using because you don’t want the liquid trapped in the connector where it might cause issues for the circuits. Most under-hood connectors are weatherproof, meaning, they have rubber seals.

Clean Components Carefully

Don’t use excessive force when scrubbing or wiping your engine parts. Some are extra sensitive to friction, so you must be careful.

Research how to clean each engine part. Is washing and scrubbing a certain component fine or should you only wipe it down? Can you dismantle it to clean its hard-to-reach spots? Knowing these details will go a long way in preventing problems down the line.

Use the Correct Cleaning Agents

Invest in high-quality engine cleaners. Before buying one, double-check its label. Make sure it’s safe to use for engine bay cleaning and that there are no chemicals that can damage the parts.

Clean Your Engine Bay When The Weather Is Warm

Do it when the temperature is a bit high so that the engine parts that got wet during cleaning will dry quickly. Don’t forget to hydrate as you work and to take breaks if the weather gets too hot.

Don’ts (Advising Against)

Use a Pressure Washer

Note: If you’re wrench smart and are prepared to deal with the issues that might result from using a pressure washer, it’s okay. If your vehicle has a distributor you’ll probably need to remove the distributor cap and use WD-40 to displace the water if cleaning the engine with water pressure causes an ignition related no-start.

But a pressure washer can, if used indiscriminately under the hood, forces water into even the weather-proof connectors and you can wind up with all manner of driveability issues, no-starts, etc. because of water in the connectors.

So although it can be tempting, try to avoid using a pressure washer to clean your engine bay. While it’ll make grime removal easier, the pressure can loosen up the fittings and connections in your engine bay.

Use a regular low-pressure garden hose instead. You can also use wet rags or spray bottles.

Use a Foaming Degreaser

A foaming degreaser can remove grease fast, but if you don’t rinse it off thoroughly, it can cause corrosion in the engine bay.

Use a rag to remove grease instead. If you need to use a degreaser, stick to basic ones—those that are also used for the kitchen. You can also use a soft bristle brush to scrub off stubborn stains, but be careful not to damage the parts.

Clean Your Engine While It’s Still Hot

Wait for your engine to cool down before cleaning it, as certain cleaning solutions react to high temperatures. Plus, you can get burns if you touch hot parts, so it’s better to pop the hood open and let your engine cool down before cleaning it.

Is Engine Bay Cleaning Necessary?

Yes. Cleaning your engine bay removes dirt or grime, preventing rust and corrosion and prolonging the life of your engine.

Plus, a clean engine helps keep your car’s value high. Potential buyers look at a clean engine bay as a sign that you took good care of the vehicle. So if you’re planning to sell your vehicle, it’s a good idea to keep yours clean.

How Often Should I Clean the Engine Bay?

There’s no set rule as to when you should clean your engine bay. It usually depends on where you live and your driving habits.

For example, it’s best to clean your vehicle’s engine bay every two to three months if you live in areas with low annual rainfall. These areas often have dusty conditions on the road due to minimal precipitation. West Texas, Utah, and some parts of Nevada, for instance, are known to have arid climates.

If extensive rainfall and snow are common in your area, it’s best to clean your engine bay every two to three months. But if you live in a city where there’s little to no debris on most roads, cleaning your engine bay twice a year will do.

How Much Will I Have to Pay for an Engine Bay Cleaning Service?

If you don’t like to go through all the hassle of cleaning your engine bay, you can always pay a professional to do it for you. Expect to shell out anywhere between $100 and $400 for an engine steam cleaning service.

Engine steam cleaning involves using high-pressure steam to remove dirt and grime from critical components in your engine. Only professionals do it because they’re specially trained to do it without damaging sensitive engine parts.