Wash & Dry

How to Wash a Car Engine at the Carwash? – 12 Steps

Written by Howell Crist / Fact checked by Sam Howard

how to wash a car engine at the carwash

Although it is not directly visible to the eyes of the public, keeping your car engine clean is important. Regularly washing your car engine will improve your car’s overall look and value.

Furthermore, it will help you spot minor issues such as oil leaks and allow you to remove dirt that could damage the engine’s aesthetics.

It is best to do this job at car wash centers. So, here is a detailed guide on how to wash a car engine at the carwash.

Step-by-Step Guide


Car engine washing sounds like a simple task. However, you should make sure to follow the correct steps and take necessary precautions to avoid malfunctions and expensive repairs.

Required materials to clean engine at a car wash

  • Water sprayer or a washer using low pressure (twice the pressure of a garden hose)
  • Plastic bags
  • Electrical tape
  • Adjustable wrench
  • Compressed air
  • Synthetic hand brush
  • Microfiber cloth
  • Vacuum cleaner
  • Degreaser
  • Protective gears (mask, goggles, gloves)

Step 1: Plan Ahead

Cleaning engine bay at car wash needs planning. Washing your car’s engine in warmer weather is best because it helps the engine dry quicker.

It is also advisable to decide ahead of time where you will wash your car’s engine. The best way to clean car engine is to do it at a place where you can get all possible things you will need at a reasonable price.

Step 2: Let the Engine Cool Down


Letting your car engine cool down before exposing it to the engine wash spray and water helps prevent damage. The metals that make up the engine will go through so much stress and may crack when you wash them while they are hot.

Besides possible metal or component cracking, water also tends to get into the engine quickly when it is hot, causing chemical reactions.

The engine cools down faster when you open the car’s hood. While waiting, you can position your materials and wear protective gear.

Step 3: Suit Up

Wear your mask, goggles, and gloves before getting dirty. Car wash with engine cleaner or degreaser will expose you to chemicals that may trigger health issues. Although some people consider this step optional, I highly recommend it.

You will be exposed not only to the fumes from the engine cleaner at car wash but also to the dust and debris. These can be harmful when they get into your eyes, nose, and throat.

Step 4: Fasten the Liquid Caps and Dipstick

Before spraying any liquid on the engine bay, ensure to tighten up all liquid caps to prevent water from getting in and mixing with the engine fluids. You must also securely press down the dipstick to avoid water from mixing with engine oil.

Allowing water to mix with car engine fluids will cause chemical reactions that could lead to damage. If it doesn’t do immediate damage, it may cause annoying troubles.

Step 5: Disconnect Battery Terminals


Using your adjustable wrench, disconnect all battery terminals and remove the battery (when possible) for safety. You need to remember that your car will not start up without a battery.

It is easier to clean the battery when you remove it. However, if it is not possible, ensure to cover the whole unit and clean it without water.

Step 6: Cover Electricals and Filter

After disconnecting the battery terminals and removing the battery, pick up your plastic bags and electrical tape. It is time to secure all electrical points and filters by covering them to ensure the water will not penetrate.

Water getting into the engine’s electrical components, such as the power source coil, spark plugs, alternators, and others, will cause trouble. Among the common issues are short circuits and failure to start.

Step 7: Apply the Degreaser


Engine degreaser car wash is the best method to clean up your vehicle’s engine. In most cases, you can avail of engine cleaner at car wash.

There are many brands of engine degreasers you can choose from. The reviews in this article may help you decide which to get.

Spray your degreaser all over the engine and let it sit for 10 to 15 minutes to ensure it can penetrate through dirt and gunk. Ensure you do not miss spraying on the ‘hard-to-reach’ engine areas.

Step 8: Hand-scrub the Engine

Your car engine washing will not be complete without scrubbing it with your synthetic hand brush. Doing this will ensure you loosen all dirt and gunk that are hard to remove.

Some people skip the brushing step as they rely so much on the engine degreaser’s performance. However, I suggest you do not skip this as it is proven to achieve a perfect clean.

Step 9: Rinse with Water


After thoroughly scrubbing, rinse the engine with water to remove all the loosened dirt. Be careful to set the pressure to a low PSI to avoid damage.

Seek the assistance of the car wash attendant to ensure that you are using the correct nozzle. The ideal pressure to use for engine washing is a pressure that is twice the pressure of a garden hose (between 100 to 200 PSI).

Some people skip water rinsing and complete the washing without water. Those who prefer to do this argue that it is safer for the engine if no water is involved in the process.

Step 10: Dry the Engine

When you finish washing, dry the engine by wiping it with your absorbent microfiber towel. You can use the compressed air at the carwash shop to complete the drying process.

The compressed air will allow you to dry the hard-to-reach areas of the engine. Ensure to properly dry the areas near the battery terminals to avoid malfunctions.

Step 11: Remove the Debris

If you have a vacuum cleaner in your car’s trunk, vacuum the engine bay to remove all debris. In case you don’t have one, you can ask a carwash staff to use the service vacuum cleaner.

It is important to also ask for the price when using the car wash’s vacuum cleaner. Some carwash may charge extra fees for using their machines.

Step 12: Reinstall Components

To finish your engine washing, reinstall all components you may have removed. Remove all the plastic bags and electrical tapes that cover the sensitive engine components.

Ensure to clean the battery before putting it back. After cleaning the battery, return it to the battery slot and reconnect the battery terminals.


There you have it!

Washing your car’s engine is important maintenance to ensure that it will look nice and last longer. You can use an engine cleaner at the car wash to make the job easier.

You can avoid potential damage if you follow these steps on how to wash a car engine at the carwash. You can now make cleaning engine bay at car wash a regular activity.

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Our chief editor is Sam Howard. The vast market of car care necessitates extensive research. He entered the market, experienced the service, and reported customer feedback in order to provide the best advice and content to car owners. We have faith in him to turn our website into a reliable resource for all car owners.

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