How to Clean a Car Engine Without Water? (Safest Way)

Written by Howell Crist / Fact checked by Sam Howard

how to clean a car engine without water

Even though proper automobile maintenance includes cleaning the car engine, most experts advise against a DIY engine wash. This is because the average car owner may not be familiar with the standard engine bay layout.

As a result, they could end up dousing sensitive electrical components with water. This, as you can imagine, is not ideal. You could damage your engine and/or get seriously hurt.

But if you insist on giving your engine a quick wash at home, it’s still fairly doable. You just need to know how to clean a car engine without water.

Step-by-Step to Clean a Car Engine Without Water


Before we begin, do note that there are several methods of waterless car engine cleaning. Car owners typically opt for whichever makes their car engine cleaner.

For this article, we’ll be introducing and explaining the Degreaser Method.

What to Prepare:

  • Engine degreaser – most people are familiar with WD40 as a degreaser, but any recommended commercial degreaser will do
  • Plastic bags
  • Electrical tape
  • Synthetic bristle brush
  • Microfiber cleaning cloths
  • (Optional) Set of wrenches – adjustable, crescent, and socket
  • (Optional) Vise pliers

Step 1: Clean Engine Bay of Debris


Before you clean the motor of your car, you need to prep it. Pop your hood open and check the engine; it should be cool enough to touch and free of big debris (like twigs, paper, grass, and the like).

Please do not attempt to degrease an engine while it’s still hot. This can be incredibly dangerous for both you and your vehicle. Wait several hours after the engine’s been shut off before working on it.

(Optional) Step 2: Remove Plastic Covers, Negative Battery Terminal, and Battery


Remove any protective plastic covers under your hood if you feel comfortable and/or confident enough about handling them. Some opt to skip this step, while others believe it is necessary for optimal cleaning.

You may also remove the negative terminal from the battery and/or the whole battery itself. Most experts agree that the engine can be cleaned without risking the battery (especially if you follow the steps to clean the inside of an engine properly).

However, if it would make you feel safer, go ahead and remove the battery using the proper tools (a set of wrenches, as listed above, and a vise plier).

Step 3: Use Plastic Bags to Protect Delicate & Electrical Components

Even a waterless engine cleaner will leave behind moisture that could damage the more delicate parts of the engine bay. Exposed electrical components like the ignition wires and control unit are especially vulnerable.

Cover these components with plastic bags and ensure the bags are taped tightly before proceeding with the next step.

Step 4: Apply Engine Degreaser

Spray engine degreaser liberally. Pay special attention to the dirtier areas.

Note: make sure the degreaser cleaning spray is formulated for your engine. Some owners may prefer petroleum-based cleaners. Others may opt for a more eco-friendly formula.

Whatever your preference is, make sure it’s safe for your model. When in doubt, consult the manufacturer.

Once all surfaces in the engine bay are sufficiently coated, allow the formula to sit for 3 to 5 minutes. This will give it time to penetrate and thoroughly break down the grease and grime in the engine bay.

Step 5: Scrub Engine with Synthetic Bristle Brush

Once the degreaser has done its work, it’s time to scrub. Using a stiff bristle brush, start with the areas with visible gunk and caked-on dirt before moving on to the rest of the bay.

Don’t be afraid to use a little elbow grease! As long as you’re using a synthetic bristle brush (and not a metal bristle brush), you won’t risk damaging or scratching your engine with some intense scrubbing.

Depending on the state of your engine, you may have to perform steps 4 and 5 again. Spray particularly stubborn spots with more degreaser, wait another 3 to 5 minutes, then scrub. Repeat this process until your engine is as clean as can be.

Step 6: Wipe Engine with Microfiber Cloth


Wipe away the loosened dirt and degreaser using a clean microfiber cloth. Start from the corners and work your way to the edges to clean oil from engine bay. Use multiple microfiber cloths if you can. Pay extra attention to crevices, cracks, and other places where the liquid is likely to pool.

Step 7: Dry Area with Microfiber Towel

Once all the degreaser oil is gone, wipe the engine bay completely dry with a fresh microfiber cloth or soft towel.

Remember that most commercial detailers engine degreaser formulas will leave behind moisture, so be as thorough as possible. As with the initial wiping, you may need to use two or three cloths to get it as dry as possible.

Helpful Tips/FAQs


What is the best way to clean an engine?

The best way to wash a car engine or truck engine is, ideally, with water and a degreaser. You would apply a degreaser to the engine first, scrub as needed, and then rinse away the residue with a hose or power washer on a light setting.

You could even use the sprayer at the carwash, if it’s available for public use.

But if you’d prefer to clean your engine without water, the best way is to use a degreaser, a scrub brush, and plenty of clean microfiber cloth. And, of course, some elbow grease!

Some experts – and car owners – report that you can even try cleaning your engine with tire foam! It supposedly has the same lifting effect on dirt and grime as a degreaser has. However, degreasing is far more popular (and tested) method.

What to cover when cleaning an engine?

To clean car engine safely, you’ll need to ensure that any components vulnerable to grease and moisture are completely protected. This means exposed electrical components like ignition wires, spark plugs, and coil packs.

You should also wrap up distributor caps, engine control units, filters, and alternators in plastic bags. The fuse box will need protection, too. Use electrical tape to secure the bags and make sure there aren’t any rips or holes in the plastic.

How do I clean a car engine with no water no scrubbing?

If you want to clean a truck engine or car engine without scrubbing it and dousing it in water, degreasing and cleaning wipes are a great alternative! These are like antibacterial wipes for your engine. Simply use as many as needed to wipe the engine down until you’re happy with the results – no cleaner spray, water, or scrub brushes are required!

Once you’re done using the degreaser wipes, you can dry the engine bay as you normally would–with a microfiber cloth or soft towel. For contactless cleaning, you also use an air compressor. These work great for cramped, hard-to-reach areas.


Between using soap and water or an auto engine cleaner/degreaser spray to clean your engine, waterless might be the best way to go, especially if you’ve never washed your engine before.

There are just too many delicate components to consider, and haphazardly spraying water all over the engine bay is a risk many experts would advise you not to take.

Washing car engine problems usually arise when electrical components get wet. Save yourself the stress and learn how to clean a car engine without water!

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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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