Can you power wash a car engine?

In this brief article, we analyse whether a car engine can be power washed.We understand the nuances of normal washing and power washing and also learn the steps of cleaning the engine bay.

To keep your car squeaky clean is often a challenge,given its exposure to ambient dirt and other pollutants.The car engine bay is often exposed to various dirt and chemicals and cleaning it requires extra effort.Power washing or pressure washing uses water injected at high pressure acting on a dirty surface,to remove loose bits of dirt,mud, grime and sometimes paints.The pressure of the powerwasher can be adjusted suiting the requirements.However, whether to use this technique on a car engine is still debatable.

What is power wash?

Spraying water to a surface at high pressure is known as power washing or pressure washing.Jets of water is sprayed through a nozzle and due to the increased pressure, it is easier to get rid of tough stains.

Can power washing be done on car engines?

While the method of power washing is handy to clean most surfaces,using it on the car engine bay is perhaps open to question as there are different opinions regarding this. While some experts advocate that power washing a car engine is safe and effective, there is a risk of improper technique that may do more harm than good.

The risk of improper power washing your car engine bay include:

1.Damages electrical components:

The engine bay houses several vital electrical components such as the alternator, battery ,Electronic Control Unit(ECU) and more. These are best if left dry.Power washing can cause disruption and damage in their operation and continued exposure to water can lead to failure.

2.May contaminate lubricants

The engine bay also houses several liquid and lubricant enclosures such as the brake fluid, transmission fluid and the like.These liquids are crucial for the operation of the car.Power Washing the engine bay may inject water into the fillers of these liquids and may compromise their integrity.

3.Cause corrosion of parts

Perhaps the greatest bane of moisture is its ability to form rust.Rusting of coils of alternator can impede its performance and cause its eventual failure. The chemical nature of the dirt can also cause adverse reactions on the surfaces.

4.Compromise other equipments in under the hood

Other plastic and rubber components,such as the covers of the battery etc  inside the hood can be either fragile or not water proof.Thus,spraying water at high pressure can cause surface damage or cracks in such parts.

So how to clean the car engine bay:

The underbelly of the hood of the car is prone to a lot of dirt and requires regular cleaning.
Having noted the above risks of power washing the engine bay, it can still be employed to keep the engine squeaky clean if done in the right way, and adequate precautions are taken.

1.Park the car and ensure that the engine is cool:

It is never a good idea to clean the engine when the car engine is running or is hot.Thus ensure that the engine has cooled down before washing.

2.Remove any detachable plastic coverings

If there are detachable and fragile covers, power washing can damage them.Thus removing such plastic parts is necessary to avoid damage.

3.Cover the electrical components with a plastic sheet

It has to be ensured that all the critical components that are of electric nature and are prone to corrosion should be tightly secured under a plastic water resistant cover.

4.Use a degreasing agent to remove dirt from the parts

A degreasing solution is recommended to clean those surfaces that are prone to be covered by grease and grime.


Use a scrubber to remove stains after application of the degreasing agent.Do not scrub hard as it can cause surface flaking.

Can pressurised air be used to clean the car engine?

While it can be done, it has limited applications. Power blowing can remove loose dirt and dust particles but are not effective against greasy and sticky dirt. In any case care has to be taken to keep the pressure to a limit so that sensitive parts are not damaged.

The Verdict:

While power washing the engine bay seems easier, it must be noted that the functionality of other systems,especially the electric components, which are located close to the engine may get compromised. However, there are also people who have been power washing their engine without any trouble for years.Thus,it all depends on the choice of the owner of the vehicle.One last word,If you really have to power wash, take adequate precautions by covering these sensitive parts. Else, it is better to play safe and follow the above cleaning method to clean the car engine.

Frequently Asked Questions: can you power wash a car engine

Should I wash my car engine?

Cleaning the car engine is necessary. However, one needs to be careful while using water on the engine.

How is power washing different from regular washing?

Power wash employs water spray injected at high pressure through a nozzle.High pressure washing is effective to get rid of stringent stains on surfaces.

Is power washing the car engine a better technique when compared to regular washing?

While power washing does a good job to remove stains on the metallic surface, care should be taken to ensure that electrical components are not damaged.

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