How to pressure wash a car engine?

This blog post will answer the question, ‘How to pressure wash a car engine?’, and cover topics like steps to pressure wash a car engine, and the merits and demerits of pressure washing a car engine.

How to pressure wash a car engine?

These are the following ways to pressure wash a car engine:

  • Covering all electrical components with a protective layer
  • Degreasing the engine 
  • Performing the washing process
  • Drying process
  • Applying a protection layer
  • Removing the wraps and plastic coverings

Steps to pressure wash a car engine?

These are the following steps to take in order to pressure wash a car engine.

Protection of all the electric components

The electrical components of a car engine need to be protected from the pressurized jet spraying of a pressure washer as they can short circuit.

A set of wraps or plastic bags can be used to cover the electrical components. The parts that need to be prioritized are as follows:

  • The distributor
  • The alternator
  • Spark plugs
  • Battery terminals
  • Headlights
  • Air filter compartment

Engine degreasing

Degreasing is used to deep clean a car engine, mainly for removing persistent dirt, debris, and gunk buildup. Using a non-corrosive degreasing solution is ideal and it must not be applied on a hot engine as the detergent fails to soak properly and might result in burning.

The degreaser should be sprayed well along all the nooks and crannies that are not easily accessible. Using a bristle brush to work the degreaser in is also a good idea so that the engine is fully coated with it.

Pressure washing

After the degreasing solution has been successfully soaked for a while, we can commence the pressure washing process. It is important to note that the pressure washer should initially be operated at the lowest pressure setting. The jet spray tip should be of a wide-angle, most preferably between 20-40 degrees.

A psi rating of under 1500 is ideal for this process. In case of unavailable pressure adjustment settings, it is necessary for the pressure washer to be operated from a distance of at least 5 feet.

The washing should carry on until the entire degreasing solution and the residual matter has been washed clean.

Drying process

The areas that can be accessed by the human hand, can be cleaned using either old pieces of cloth or even microfiber-based towels. The areas that are inaccessible can be left out in the open to be dried by the sunlight.

Applying a protection layer

For applying a protection layer, it is advisable to use a vinyl/plastic spray and let it sit for a few minutes before wiping off any residue.

For buffing the protective layer, a microfiber-based cloth or a towel can be used to give it a shiny texture.

This procedure not only helps in protecting the vinyl/plastic coatings but also gives them an appealing look.

Removing the wraps and plastic coverings

It is important to remove the plastic coverings and wraps that were used to protect the electrical components from getting affected by pressure washing as not doing so will cause the engine heat to melt the plastic, thus creating a new and serious problem.

Merits and demerits of pressure washing a car engine

These are the following merits and demerits of pressure washing a car engine that need to be kept in mind.


Using a power washer tool

Using a power washer tool is beneficial for this process as it allows for a lot of customization and attachments. This helps in cleaning the specific areas of the car in a more efficient manner.

A good example can be noted by using a spray hose instead of the usual nozzle for pressure washing. A pressure regulating tray for adjusting the washer pressure is another innovative attachment that can be used for more efficiency and saving time.


Pressure washing a car engine is a much more time-saving process than the conventional hand cleaning process, as it saves a lot of time.

The jet spray being pressurized can help in loosening persistent dirt and gunk buildups and can help clean areas where a normal bristles brush or cloth cannot access.

Pressure washing from home

If an investment in pressure washers and their consequent setup has been made along with all the protective coverings that are required, this process can easily be done at home by calling over a professional mechanic.


Too much pressure

A pressure washer blasts water at a significant force, however, low the pressure settings are. The electrical components like distributor, alternator, headlights, etc. must be protected before commencing the process or else they can suffer significant damage.

Incorrect cleaning agents

It is important to choose the right chemical composition in the cleaning agents for the engine, as harsh chemicals can harm the engine more than cleaning it.

Usually, a degreasing agent that is bio-degradable in nature is a good choice for cleaning the engine. A DIY engine cleaning solution also works.

Older cars are prone to damage

Modern cars have tightly sealed electrical components and also have a protective seal over them, whereas older cars have more exposed components and lack a tightly sealed protective layer over them.

Research has shown the best and most reliable pressure washers available on the market.


This blog post addressed the question, ‘How to pressure wash a car engine?’.

We understood the various ways in which pressure washing a car engine can be done. Furthermore, the merits and demerits of pressure washing a car engine have also been discussed. Please feel free to comment on the content or ask any questions in the comments section below.

Frequently Asked Questions (FAQs): How to pressure wash a car engine?

Is it OK to wash a car engine?

It is perfectly fine to wash a car engine, provided the crucial electrical components are covered well and there are no parts that are exposed to water, or else they can suffer heavy damage.

Can I spray my engine with water?

In modern cars, it is alright to spray the engine bay using water as the components are generally waterproof and have a protective seal over them.

What happens if water enters the engine?

Water entering the engine should be avoided at all costs as it can give rise to potential issues in compression, and can cause severe piston damage and eventually breaking.


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