The 3+ BEST Engine Flush Products (Reviews) in 2021

car engine

Regularly flushing your engine will help with longevity and keep it running in prime shape. It’s not surprising that the engine runs poorly when it’s clogged up with deposits, dirt, and other debris.

Performing an engine flush helps clean out this unwanted sludge and allows the engine to run smoothly. This is definitely one of those parts of car maintenance you don’t want to overlook.

In this post, we put together a list of the best engine flush products currently available online. This saves you time from having to do the research so you can focus more on properly maintaining the engine in your vehicle.

Let’s jump right into it!

The Best Engine Flush Products

Liqui Moly 2037 Pro-Line Engine Flush

Liqui Moly 2037 Pro-Line Engine Flush

The Liqui Moly 2037 Pro-Line Engine Flush is our top recommendation as the best engine flush cleaner. It’s easy to use and will safely and quickly remove harmful deposits, unwanted debris, and other byproducts of combustion.

With this product it’s no longer a headache to flush the engine on your vehicle. It starts with pouring the Liqui Moly 2037 Pro-Line Engine Flush into your warm engine, then letting it idle for about 15 minutes.

Next, you’ll want to drain the oil, replace the filter, and add new oil to the engine. This is all you need to do for the engine flush process with this product.

The Liqui Moly 2037 Pro-Line Engine Flush is made from a specialized formula that contains additives designed to effectively eliminate the dirt, grime, varnishes, and other unwanted byproducts that accumulate in the engine. Regardless of your vehicle type, this can be used as both a gasoline engine flush and diesel engine flush.

The main concern people have with this flush is that it doesn’t reduce oil consumption. Those of you with vehicles that are burning oil might want to consider a different product.

Otherwise, we would recommend the Liqui Moly 2037 Pro-Line Engine Flush as the best engine sludge cleaner for most engines. It’s easy to use, well reviewed, and super affordable online.

STP High Mileage Engine Flush Formula

STP High Mileage Engine Flush Formula

The STP High Mileage Engine Flush Formula is our next recommendation if you’re looking for the best engine flush for high-mileage vehicles. This product provides a concentrated deep clean for high-mileage engines with more than 75,000 miles.

The way this formula works is by dissolving the carbon deposits that build up in the intake valves and combustion chamber in the engine. It also clears away the sludge build-up that’s found on the cylinder heads, which will stretch out the effectiveness of your next oil change.

The main reason we love the STP High Mileage Engine Flush Formula is because it’s easy to use and formulated to quickly provide results. To get started with the flush, it’s as simple as pouring this product through the warmed-up engine.

Those of you that have noticed your engine running loudly should see an immediate improvement as the engine quickly quiet down. It’s a great product for drivers suffering with engine noise and helps to cut down on knocking usually found in higher-mileage vehicles.

The only concern worth mentioning about the STP High Mileage Engine Flush Formula is that you don’t get too many uses out of a single bottle. It’s also important to keep in mind that there are consequences of using any solvent in the engine, since they may not completely remove all deposits.

Overall, the STP High Mileage Engine Flush Formula is another great choice for the best engine flush product. It’s easy to use, readily available, and bound to provide you with the results you’re looking for when it comes to your engine Health.

Wynn’s Engine Flush

Wynn’s Engine Flush

Wynn’s Engine Flush is a simple flushing product that’s designed for both gasoline and diesel engines. It’s easy to use and can be quickly used to flush and dissolve varnish, sludge, and other unwanted contaminants found in the engine.

The next time you’re ready for an oil change, consider starting off with running this through the engine. It helps to clean out all of the internal vital engine components and stops the contamination of new engine oil.

Rather than dumping in new oil and mixing it with the old, it’s a good idea to run this through the engine beforehand. Let the car run for approximately 15 minutes, add this to the oil intake, and wait another few minutes for everything to cycle through.

When you’re ready, perform the intended oil change and then add the new oil. The Wynn’s Engine Flush product will have removed unwanted sludge, debris, gunk and other contaminants from your engine leaving it fully refreshed.

It’s a good idea to use this product if you notice your vehicle is burning oil, suffering from lower fuel efficiency, or if there are unusual noises coming from the engine. Don’t forget to read the instructions to see how much you’re supposed to use and how to properly use this for flushing your engine.

Overall, the Wynn’s Engine Flush is another great choice for cleaning the engine internally and removing harmful deposits. It’s easy to use, affordable, and another one of our top recommendations as the best diesel engine flush that will work on gasoline engines as well.

Sea Foam SF-16 Motor Treatment

Sea Foam SF-16 Motor Treatment

Our last recommendation would be the Sea Foam SF-16 Motor Treatment. This is a great engine flush formula that offers a focussed approach to flushing the engine.

The Sea Foam SF-16 Motor Treatment features a formula that’s designed to target specific parts of the engine. These parts include the carburetor jets, passageways, and fuel injectors.

It also focuses on flushing out the pistons, cylinders, and intake valves. Engines that are equipped with these components will want to take advantage of this engine flush to ensure everything is thoroughly cleaned.

The Sea Foam SF-16 Motor Treatment is more of a motor oil flush that meticulously dissolves any oil residue found in the crankcase and other engine components. It also goes to work on cleaning out the fuel system to make sure there is no leftover fuel residue still lingering.

This is a systematic approach that’s ideal for restoring engine performance and efficiency. It’s a great product to use, especially for older vehicles or higher-mileage vehicles that might be suffering from some running Issues.

Overall, we would definitely recommend checking out the Sea Foam SF-16 Motor Treatment. This is a great product for treating your engine and trying to get it back to its prime running shape.

The Benefits of Engine Flushes

Remove, Dirt, Sludge, and Unwanted Deposits

As you drive, sludge, gunk, and carbon deposits accumulate in your engine. This reduces power, fuel economy, and increases the wear of the engine components.

Performing an engine flush in your vehicle helps to remove the dirt and deposits that can negatively impact the vehicle’s performance. This helps to get your vehicle back and its prime running shape and keeps the engine happy.

Clean Engine Parts That Are Hard to Access

It’s almost impossible to access most of the engine parts and components without taking the engine completely apart. Using the best engine flush products you can easily clean out these vital engine components without needing to remove anything.

Removing parts and components to clean out the engine is a time-consuming process. There’s even the risk that you forgot to put something back in the proper order. That’s why it’s always a good idea to use an engine flush product for the best results.

Keep the Motor Oil Clean

Adding new, clean oil to your dirty engine means the fresh new oil won’t be clean for very long. With a high quality engine flush, this ensures that there isn’t any sludge or harmful deposits left behind when you change the oil.

This way the new oil can properly lubricate those vital engine parts as effectively as possible. There’s no need to worry about the old oil contaminating anything or increasing wear and tear on your engine.

Improve Vehicle Fuel Economy

If you’ve noticed declining fuel economy with your vehicle, it might be time for an engine flush. This is due to the contaminants circulating throughout the engine.

What happens is that the oil breaks down and its viscosity is increased. This results in increased resistance, which is further exacerbated by the sludge and deposits on engine parts.

The increased resistance makes the engine work harder for the same result, which lowers your fuel economy. Cleaning the engine with an engine cleaner flush helps to maximize your fuel economy by keeping the important parts moving more efficiently.

Minimize Emissions

The problem with leftover carbon deposits is that they can find their way into the combustion chamber and burn off. This results in harmful leftover deposits and increased exhaust emissions, with the burned oil exiting the tailpipe.

Taking advantage of the best oil flush treatment helps to free stuck piston rings and minimizes oil consumption. This lowers your emissions and keeps the engine running smoothly.

Types of Engine Flushes

vw tsi engine

Gasoline Engine Flush

Most of you will be performing a gasoline engine flush, which is specially formulated to work in gasoline vehicles. There are even gasoline engine flush products designed for particular applications, such as high-mileage engines.

These products are designed to work as quickly as possible to get your engine running more efficiently. The best oil flush products for gasoline engines use a proprietary blend of additives to remove the harmful deposits and sludge from your engine.

Diesel Engine Flush

Those of you with diesel engines will want to use a diesel engine flush. This type of engine flush is designed for diesel engines to flush out the harmful carbon deposits and sludge that buildup in diesel engines over time.

There are even diesel engine flush products available for diesel trucks or SUVs. Look for the particular product that’s best designed for your vehicle.

Gasoline and Diesel Engine Flush

There is one more type of engine flush available and that’s one that’s designed to work effectively in both diesel and gasoline powered engines. This is a convenient engine flush product because it can be used in either engine type, meaning you don’t need to worry about buying a specific product.

Engine Flush Pricing: How Much Does an Engine Flush Cost

Under $10

There are some great options available for less than $10. Those of you on a budget can find some decent performance products in this price range.

$10 to $19

Most of the best motor flush products can be found in this price range. There is a wide range of products available to choose from offering countless different features and benefits.

At this price point you’re looking at products that are easy to use and that deliver excellent performance. Most of you will find something relevant in this price range to use for your own vehicle.

Over $19

There aren’t too many options available that are priced over $19. Around this price you’ll find some of the best oil flush products, though some of the cheaper options tend to be just as effective.

The difference here is that you’ll be paying mostly for branding and marketing, as opposed to the quality of the product overall.

Key Features

clean car engine

Engine Compatibility

One of the most important features when you’re looking for engine flush products is the engine type compatibility. Motor flushes are usually compatible for either diesel or gasoline engines, with some being suitable for both engine types.

To get the best result, only use the engine flush that’s specifically formulated for the engine in your vehicle. Most people find using an engine flush treatment that’s designed for both gasoline and diesel engines to be easiest since there’s no need to worry about engine compatibility.


Most engine oil flush products use solvents to help the process of cleaning the sludge, gunk, and carbon deposits that have accumulated in the engine. Avoid using any engine flush that contains too many solvents, as this can deteriorate the engine gaskets and seals.

Instead, look for products that come with mild solvents. These will be the best for most engines and provide the most effective cleaning capability.


Something else to consider is the user-friendliness of the engine flush products you’re looking at. Most engine oil flushes are easy to use without having to need an engine flush machine.

On the other hand, a few of them require using a special tool that attaches to a garden hose for flushing of the engine. Keep in mind your mechanical skill level and any time constraints when you’re looking for the right product for your flushing needs.


Engine flush products contain a blend of specific additives that have been mixed into a single solution. Different engine flush products use different additive blends depending on the brand and purpose.

These blends are specifically engineered for delivering a particular result. The best engine flush product is generally made with a mix of detergents, dispersants, rust Inhibitors, lubricants, and anti-wear additives.

Keep an eye out for engine flush products that contain at least a few of these additives. This will provide the most efficient and maximum cleaning power for flushing out your engine.

Quick Results

One more feature to consider is the time constraint when it comes to flushing your engine. Most people are looking for engine flush that’s designed to provide quick results.

Many popular brands are able to work in as little as 15 minutes. This helps to save you time and makes the process even easier when you’re flushing the engine.

Helpful Tips

  • Always follow your owner’s manual for oil change frequency. Use a premium quality synthetic oil for the oil changes in your vehicle. These higher quality oils are designed to prevent the accumulation of carbon deposits, grime, and sludge in your vehicle’s engine.
  • If possible, avoid taking short and frequent trips around your city. Stop and go driving is the biggest cause of harmful deposits and such that build up in your engine. This can negatively impact both the performance and fuel economy of your vehicle.
  • Avoid any engine flushes that contain harsh chemical solvents. These harsh solvents will accelerate the wear of your seals and gaskets, which can eventually lead to mechanical issues. If you’re having problems with stuck lifters or rings, consider using an engine flush product that’s formulated with mild solvents.
  • The best time to do an engine flush is right before you’re about to change the oil. This strategy gets all of the accumulated carbon deposits and sludge flushed out along with the old oil.
  • Always reads the engine flush bottle for the instructions, oil grade compatibility, and any relevant expiration dates. Double check with your owner’s manual or online for how to perform an engine flush on your vehicle.
  • Along with an engine flush, consider cleaning the fuel injectors on your vehicle as well. For that, check out our post on the best fuel injector cleaners to find some products for the job.


What is an Engine Flush?

An engine flush is when you use aftermarket additives to flush the deposits, sludge, and other gunk that has accumulated in the engine of your vehicle. It’s as easy as pouring the flush product into the engine oil intake port.

Next, you would let the engine idle for approximately 10-15 minutes, depending on what’s recommended in the instructions. The product would then blend with the oil and circulate through the engine.

The additives in the engine flush would dissolve sludge and other unwanted gunk throughout the engine compartments. After the time has elapsed, you would drain the oil, change the filter, and finish the oil change with fresh oil.

How Do You Know if the Engine Needs to be Flushed?

If you’re regularly taking short trips with your vehicle then it’s likely that carbon is building up in the engine. You might notice that the vehicle doesn’t feel as peppy or there is a drop in fuel economy.

Should you notice any of these symptoms, it would be a good idea to flush the engine. Other symptoms would include signs of oil splatter, sludge under the hood, premature oil change light, or sludge that’s present in the oil pan.

What’s the Best Way to Flush Engine Oil?

While it’s possible to use an engine flush machine, it’s not usually necessary for most DIY flushes. They can speed up the process, but they’re very expensive to buy or rent.

It’s easy to get the job done without using a flush machine. As long as you know how to change your own oil, then you’ll be able to flush the engine on your own vehicle without difficulty. There are plenty of useful accessories you can use, such as an oil drain pan, which would make the job even easier.

How Long Does an Engine Flush Take Without a Machine?

The time length would depend on the motor flush that you’re using. You can expect the best engine sludge cleaners to take as little as 15 minutes for the process, depending on your mechanical ability.

If it’s the first time doing it or you’re not confident in your mechanical skill, it could take a little while longer. It’s a good idea to refer to YouTube for some helpful tips on how to flush your vehicle engine.

How Much Does an Engine Flush Cost?

Looking at our recommendations above, you can expect to spend between $6 and $20 for a bottle of engine flush. Don’t forget you also need replacement oil and a new oil filter for the oil change you’ll be doing.

This is something you can easily and affordably do at home, on your own. However, if you need the help of a mechanic, you can expect to pay up to $150 for parts and labor.

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