How to clean engine bay?

Susan Fernandez November 11 2021

The engine bay can claim to be the most underappreciated part of the car when it comes to detailing. You see it only once when changing the oil by yourself. And that’s all. Although the engine bay is underappreciated, it contains some essential advantages why you should detail it several times a year. And here, in our post, we will discuss this.

Where is the engine bay located?

The engine bay is the frontest part of the car where you can see the motor, ignition coils, air filter, gas tank, and other essentials. It’s also independent of the cabin interior even though it is located in between them. And finally, there are not many exterior parts to be detailed within this area with exception of the hood which covers it all.

Why do you need to clean it?

Firstly, let’s understand why it’s necessary to clean our engine bay. So, during the years, all engine’s plastic and rubber elements face challenges because of the extreme heat. And here, the engine bay detailing plays a very significant role – it enables to avoid a high-cost repair, plus it allows examining the conditions of your engine between the maintenance periods. 

When should you clean it?

As we said before, the engine bay can be cleaned several times a year. But let’s divide these cleaning sessions into three categories:

  • Engine bay cleaning during hot seasons – In these long summer months, as well as in some spring periods, the sun may cause some heat discoloration on your car’s upper side. Therefore, our recommendation is to wash your engine at this time of the year. It will help to avoid a more expensive repair than you would have had if you didn’t wash it.
  • Engine bay cleaning between maintenance work intervals – Usually, auto mechanics recommend an annual service for cars under warranty and two years for those not under warranty. However, if you have a car with higher mileage, you should see an expert more frequently. And here, at this point, engine bay detailing becomes very important because during these inter-visiting periods the service shop is unable to examine your engine closely. So, in order not to spend too much, you should wash it yourself before showing up at the auto repair shop. 
  • Engine bay cleaning between maintenance work intervals (after washing) - After washing your engine for the first time during that year or after taking it to an auto repair shop for its seasonal checkup, some dirt and dust may remain between the plastic elements of your engine bay. Therefore, we recommend cleaning them before starting any long travel (over 300 km) on hot weather some days after washing the engine bay.

When is it better to clean the engine bay?

Generally, it’s recommended to do it on a warm day when it’s a little cloudy. If you clean the engine bay on a hot day, the direct sun can harm the engine bay’s area and make the chemicals dry. If you cannot do it the other day, you need to clean the engine bay section by section.

How to clean it?

So, how to correctly clean the engine bay? What do we need for it? First of all, let’s see what products and appliances we need – microfiber towels, mirror shine, Decon soap, universal cleaner, and plastic restore. Besides, you also need a vacuum cleaner, air hose, or leaf blower to remove the dirt (it’s not obligatory) and various brushes. Don’t forget about the safety tools – glasses, rubber gloves, soapy water, and a dust mask.

The second thing you should remember is to do dry cleaning. With a vacuum cleaner, you will easily remove the dirt, dust, and leaves. Using a detailing brush, you will clean the minor parts which the vacuum nozzle cannot reach. If you have a leaf blower, it will also be very helpful to remove the dust from the engine bay. And never forget about the safety tools! This way, you’ll definitely get rid of the surface dust and get off grime from the engine bay.

Before using any chemical liquids or water, we strongly recommend you disconnect the battery from your car. This way, you’ll avoid a short circuit, plus your car and you will be safe. Besides, we also advise you to cover all sensitive engine bay areas. You can use rubber bands, plastic bags, and aluminum foil.

After that, you can take a garden nose and wash your engine bay. We recommend starting washing from the hood’s bottom and then slowly going down. This way, you’ll wash off all left dirt, plus you’ll lubricate the detailing brushes for the next phase.

Wash it all

During the engine bay cleaning, you’ll probably notice some difficult-to-reach areas. Therefore, to remove any dirt or dust from them, we advise using a vacuum cleaner (with its nozzle) or an air hose. It will help you clean hard-to-reach areas very quickly and easily.

After finishing wiping down all sides of your car's hood section, then wash out a rag a few times with hot water in order to get rid of dirt and debris from it. Then wipe down your engine bay using a dry microfiber towel.

In order to completely clean up the engine bay, you should use some spray cleaners in different areas. In order to get rid of dust from the plastic parts and rubber seals, we advise using an air hose with a nozzle or a leaf blower. It will also help you wipe down hard-to-reach places. When that’s done, use a detailing brush to clean all the remaining spots of any dirt and debris.

When it comes to applying liquid chemical products to your car for cleaning purposes, we strongly recommend using soapy water in this case. If you want to apply chemicals on some metal parts during this process, dilute them properly before doing so because they can cause corrosion.

We also advise you to use plastic restorer spray (which can also help you clean any remaining dirt) and wipe down the surface with a microfiber towel. This way, it will be easy for you to make your engine bay shine like new!

Then we come to the degreasing phase. Take the cleaner of degreaser and spray it on all the dirtiest areas firstly, and then spray it on the rest areas. Leave it for some time, then take the garden nose and wash all dirt and cleaners away. If you want to, you can do some pre-waxing phase on your engine bay, this way it will shine after the waxing touch.

After that, take some metal cleaner on any metal part which needs cleaning. After applying it, use a microfiber towel for wiping down the surface where the cleaner has been applied. All remaining dirt and dust should be easily wiped down on that spot.

Finishing cleaning process

To ensure that you remove all cleaner liquids and dirt, you can use the Decon soap. Mix it with water and spray it on the whole engine bay. Then again, take the garden nose and wash it away. After that, you can take the microfiber towel and wipe down your engine bay.

After finishing this process, we strongly recommend re-checking all the engine bay parts and other sensitive areas before putting them back together. Make sure no other fluids or liquids got into those spots where they shouldn’t be. Then reconnect your battery and drive your car around for a bit to let everything dry off completely before starting long road trips. If your journey is going to be short, then don’t worry – the next day after the engine bay,

So now, your engine bay is clean, and you can easily start detailing it. Here, you can use various plastic or rubber conditioners, wax, and paint sealants.

Mistakes to avoid

Never forget to disconnect the car's battery. Otherwise, you can get shocked or damage some parts of your car.

You should wash out a rag properly with hot water before using it for wiping down anything else. Otherwise, everything will just stick onto that rag.

Don't use too many chemical products on one spot at once because corrosion problems might occur in the future.  Also, check if there are any cleaners on any surface before driving off. If so, spray some soapy water or wipe it with a microfiber towel instead of driving off immediately because you don’t want to scratch dirt into your car’s paintwork while driving off.    

Car parts that you shouldn`t make wet

  • battery terminals
  • brake pads and rotors
  • brake lines
  • anti lock brake system (ABS) components and sensors
  • power steering and power brakes parts
  • clutch cable and hydraulic parts that don`t deal with wheels

It is important not to make them wet because if they are, you can damage them so much by doing so.

Bottom line

Most of us work day in and day out under the hood so it’s nice to spend a little time cleaning up that engine bay. It can be a very tough job, but you should always remember that being properly organized will save you a lot of time, while also making sure that everything is ready for use when you need it.