Even if you regularly clean the interior and exterior of your vehicle, there is a good chance that you do not clean your engine. Many people don’t attempt to clean their engine bay because the dirt and grime is often far tougher than anything that accumulates on the body or the interior carpeting. Your average all-purpose cleaner won’t remove burned-on oil from around the edges of your valve covers or the dirt that is cooked onto the top of the engine cover. That is where an engine degreaser comes into play.

Cleaning the gunk on your engine takes a special product that is made to eat through the mixture of dirt and oil that has been baked at high temperatures for long periods of time. Removing grime like that requires a specially formulated engine degreaser that will break down and loosen under-hood filth.

If you are obsessive about the cleanliness of your vehicle and you know that the engine bay requires a special cleaner, you may be unsure of which to select. Whether looking online or at your local parts store, there are many brands of engine degreasers on the market. In this article, we hope to make shopping for the best engine degreaser a bit easier, so you can get to cleaning that dirty ‘ol engine bay.

For more information on the best engine degreasers, refer to our table of contents.

1. Editor's Pick: Chemical Guys Signature Series Orange Degreaser

Chemical Guys Signature Series Orange Degreaser

Chemical Guys Signature Series Orange Degreaser uses a citrus-based formula to remove grease, grime, dirt, and other debris that accumulates in your engine bay. While it is designed to be used to break down baked-on mixtures of dirt and various lubricants, it can also be used to loosen grime on the wheels and undercarriage areas of your vehicles. If you get road tar or other sticky materials in your wheel openings, the Chemical Guys Signature Series Orange Degreaser can help remove it quickly. You can even use it on tools or on your garage floor, all of which can gather similar gunk to that found in an engine bay.

Using the Chemical Guys Signature Series Orange Degreaser is simple. You spray it on the affected area and wipe it away. In areas with thicker grime, you may need to add a little elbow grease. In areas where it is safe, including the wheel wells or select areas around the engine bay, you can put down a thick layer of Chemical Guys Signature Series Orange Degreaser, let it soak a bit, and rinse it away with water.

In addition, to knocking out tough dirt, the Chemical Guys Signature Series Orange Degreaser also leaves behind the pleasant smell of oranges.

2. Best on a Budget: Gunk Original Engine Bright

Gunk Original Engine Bright

If you want to knock out engine gunk, there is arguably no better product than Gunk Original Engine Bright. Gunk is one of the best-known brands in the industry and the Original Engine Bright is one of its best selling products. It is specifically engineered to remove tough grease and oil build-up on older engines, particularly in the case of vehicles that have suffered from fluid leaks.

Gunk Original Engine Bright is designed to tackle the toughest engine bay mess and it does so without any scrubbing. You simply spray the Original Engine Bright on the area that you want to clean and wait 10 to 15 minutes. During that time, the Gunk spray eats into the baked-on grime, lifting it off of the various surfaces. After 15 minutes, you rinse the engine down with water and grime washes away.

Best of all, in addition to being one of the best-known brands of engine degreasers, Gunk Original Engine Bright is one of the most affordable engine degreasers available. For particularly tough jobs, Gunk offers other, high-strength engine cleaners, but for the majority of vehicles, the Original Engine Bright will get your under-hood area looking like new.

3. Griots Garage Engine Cleaner

Griots Garage Engine Cleaner

Griots Garage Engine Cleaner is a mild degreaser that is designed for shining up reasonably well-maintained engine bays. While some engine degreasers use harsh chemicals to remove grime that has been cooked into place for years, the Griots Garage Engine Cleaner is designed for the automotive enthusiast who wants to regularly clean their engine.

If your engine bay is part of your regular vehicle detailing program, Griots Garage Engine Cleaner is the product for you. It loosens and removes dirt that collects on the engine during normal driving. If you have a hood with heat extractors or a hood scoop, you might find that the engine gets very dirty when driven in the rain. This cleaner is designed to remove that dirt without any harsh chemicals, shining up your powerplant for the next car show.

Using this product involves simply spraying it on the dirty area and taking a microfiber towel to it to help break up any stubborn solids. Once everything is loosened up, a quick rinse removes the cleaner and the dirt, while a quick wipe-down with a dry towel will prevent any water spots.

This recommendation is one of the most expensive engine degreasers on this list, but if you regularly clean your engine bay, you are likely to find it’s best for your needs.

4. Sonax Engine Degreaser and Cleaner

Sonax Engine Degreaser and Cleaner

Sonax Engine Degreaser and Cleaner is designed to remove oil, grease, grime, and other debris from your vehicle’s engine. The spray bottle gets the strong cleaner into tough spots, where it then soaks into dirt that you can’t even see, helping to remove every last bit of grime around the engine bay. It is phosphate-, solvent-, and acid-free, yet it is still formulated to remove engine filth on a professional level.

Sonax Engine Degreaser and Cleaner is designed to be used on a no-touch basis, but with the grimiest engines, you may need to do a little scrubbing. You begin by spraying the areas where you want to remove engine grime and let it sit for three to five minutes. You then rinse away the dirt, oil, and debris with a strong water jet. If you find that some grime is left behind, you may need to hit the spot with a bit more of the solution, followed by a quick once-over with a scrub brush. After that, you just rinse away the mess and enjoy your nice, clean engine.

Sonax does recommend that you avoid electronic components in the engine bay and you only use the cleaner on a cool engine, out of direct sunlight. Using it on a hot engine could cause the product to dry too quickly, preventing proper cleaning and leading to spots on black plastics.

5. WD-40 Specialist Machine & Engine Degreaser Foaming Spray

wd-40 specialist degreaser spray

You likely know the WD-40 brand for breaking down rust and loosening bolts, but WD-40 Specialist Machine & Engine Degreaser Foaming Spray is designed to break down baked-on grime on your vehicle’s engine. The aerosol can sprays up to five feet, allowing you to attack dirt in areas that you cannot reach, with the water-based foam eating into the various engine bay crud.

You simply spray this product onto the areas of your engine with tough grime. The foam sticks to those areas and expands into small spaces, breaking down the oil, grease, dirt, and grime under it. After allowing it to soak, you simply wipe away the filth. Since it is water-based, it does not damage rubber or plastic, and unlike many harsh chemical cleaners, there is no strong smell. In some cases, spraying more of the foaming spray will help to knock out any remaining debris.

In addition to using this on your vehicle’s engine, the WD-40 Specialist Machine & Engine Degreaser Foaming Spray can also be used to clean tools, power equipment, farm machinery and gear-and-chain combinations. As well as the original WD-40 breaks down rust, this recommendation breaks down tough dirt and grime on all sort of engines and tools.

Engine Degreaser: Everything You Need to Know

best engine degreasers

Photo credit: Nor Gal / Shutterstock.com

If you have ever been cleaning your car and you decided to clean off the engine with the same soap with which you cleaned the body, the odds are good that you weren’t very successful. Normal car wash soap and even some all-purpose cleaners won’t make a dent on the combination of dirt and oil that has been baked at extremely high temperatures for years. In most cases, normal soaps will just run off of engine grime without making any difference. To tackle that cooked-in grime, you need a designated engine degreaser.

Engine degreaser generally contains ingredients that will cut through oil-based grime, loosening the black crud that is caked like paint onto tight spots around the engine bay. Some use natural products like citrus oils, while others use solvents and other chemicals to cut through the grease and grime. In some cases, the grime is light enough that just a solid spray with a good degreasing product will remove the unwanted dirt. In the case of heavier, thicker grime, letting the degreaser soak in followed by hitting it with a brush is necessary.

There are also engine degreasers that are meant for regular use by folks who often clean and show-off their engines, but cleaning your engine bay isn’t just about looking good. Over time, excessive build-up of dirt and grime on your engine can cause mechanical issues while also making the engine harder to work on when it comes to normal, preventative maintenance.

When shopping for an engine degreaser to use on your car, you want to consider several things. First and foremost, if your vehicle is older and the engine bay has never been properly cleaned, you are going to want one of the stronger products. They are made to tackle the worst underhood filth, which is ideal for someone who only cleans their engine once in a while. For instance, if you are selling a used car and you want the engine to look great, a strong engine degreaser is a must.

On the other hand, if you have a newer vehicle with an engine that is dirty from dust and moisture of everyday driving, there are engine cleaners that are intended to remove light grime and shine up the engine for things like car shows. If you clean your engine every week, the milder cleaner should do the job for you, while also preventing the need for a harsher cleaner in the future.

We are committed to finding, researching, and recommending the best products. We earn commissions from purchases you make using the retail links in our product reviews. Learn more about how this works.

Photo credit: Nor Gal / Shutterstock.com