Best Oil Leak Stop in 2021 (Top 10 Reviews & Buying Guide)

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Do you often find your engine draining more oil than expected? Chances are that there are leaky gaskets and worn seals present on your engine. Using a vehicle regularly often causes these slight occurrences, which if not treated, ends up costing you a hefty bill.

Luckily, using an oil stop leak more often than not solves most of these said issues. When it comes to choosing the perfect remedy for your problem, things, however, can get a bit trickier.

This guide discusses what differentiates the best oil leak stop from other mediocre additives followed by some of our recommendations.

In case you don’t want to read the entire article, you can take a look at our top 3 choices for the best oil leak stop here:

Best Overall
Lucas Oil 10278 Engine Oil
Best for the Money
BlueDevil Oil Stop Leak For Diesel and Gasoline Engine
Best Cheap Pick
Bar's Leaks 1040 Grey Concentrated Rear Main Seal Repair
Lucas Oil 10278 Engine Oil Stop Leak, 1 Quart
BlueDevil Oil Stop Leak
Bar's Leaks Concentrated Rear Main Seal Repair -...
Special Features
Compatible with petroleum, semi-synthetic and full synthetic motor oils
Works with both diesel and gasoline-powered engines.
Specifically designed to seal rear main leaks
2.02 pounds
1.0 pounds
1.1 pounds
Best Overall
Lucas Oil 10278 Engine Oil
Lucas Oil 10278 Engine Oil Stop Leak, 1 Quart
Special Features
Compatible with petroleum, semi-synthetic and full synthetic motor oils
2.02 pounds
Best for the Money
BlueDevil Oil Stop Leak For Diesel and Gasoline Engine
BlueDevil Oil Stop Leak
Special Features
Works with both diesel and gasoline-powered engines.
1.0 pounds
Best Cheap Pick
Bar's Leaks 1040 Grey Concentrated Rear Main Seal Repair
Bar's Leaks Concentrated Rear Main Seal Repair -...
Special Features
Specifically designed to seal rear main leaks
1.1 pounds

What Is an Oil Stop Leak and What Are the Benefits of Using It

Over a period of usage, engine components may become dry and rough. This leads to the parts shrinking. Such effects lead to cracks as the surface pulls away.

Leaks may not be a major issue for a short period. However, over time this can lead to engine damage which becomes very costly to repair.

Why not stop the leak as soon as you see any signs and save yourself from the bigger expenses? Some mechanics would suggest that you replace affected parts whenever there is a leak. This is not ideal if the cracks are tiny and can be easily closed with an oil stop leak.

An oil stop leak is a fluid that you add to the engine oil to close the cracks and reduce or stop leaking. The fluid achieves its goal in two ways.

By using particles that are forced into the crack by the engine’s pressure. A region of low-pressure forms around a gap and the particles are forced into it, sealing it.

An oil stop leak is a temporary solution in some cases. It is better that you visit the garage sometime after you fix a severe leak. The reason we suggest this is because sometimes oil leaks can indicate a much bigger issue that may require professional aid.

Oil stop leaks should only be generally considered as a preventative measure to reduce damage to your car until a certain threshold. Below are some of the benefits of oil stop leak:

A woman fixing the engine under the vehicle

Protecting Seals

Components such as gaskets and seals are common oil leak points. They shrink, letting the oil seep out.

Additives also work by swelling these parts and restoring them to their original size and shape. Thus, stopping engine oil leak from these parts.

Saving Oil

It’s obvious, isn’t it? These leak stops help you save oil. Oil leakage can harm your vehicle, not to mention the environment. Being late to treat the problem might mean you’ll be slapped with other associated problems, like decrease in engine performance.

Saving Money

Oils are liquid gold, and leakage means you’re losing money as long as that keeps happening. If it’s too late, you might have to go to a garage to address the issue.

That means countless hours, labor and money lost in the process. You might even end up spending hundreds of dollars for something that once were a simple problem.

Our Top 10 Best Oil Leak Stop Reviews in 2021

ATP AT-205 Re-Seal Stops Leaks

ATP AT-205 Re-Seal Stops Leaks, 8 Ounce Bottle

ATP products are the gold standard when it comes to engine oil additives. They are highly recommended by professionals and almost always guarantee satisfaction to users. You can never go wrong with their products.

The ATP AT-205 Re-Seal Stops Leaks is no exception. This ingenious additive is composed in such a way that it offers maximum support to the oil, without compromising its integrity.

This additive works miraculously in rejuvenating the rubber seals and gaskets in the engine, restoring them to their previous size and shape. This is an essential solution to stop oil leak problems especially if the engine you are using is relatively old and has been showing signs of erosion.

The formula does not contain petroleum distillate to ensure complete safety to your engine. Due to this, it is a viable method to prevent oil leaks in the long run as the absence of petroleum distillate means long-lasting health for the engines.

A wide range of oil types can work with AT-205 such as synthetic oils, semi-synthetic oils, and mineral oils. It is compatible with both diesel and gasoline-powered engines, as well as hydraulic oils, transmission and power steering fluids.

What we love the most about this smart solution is its activation rate. There is not another formula on the market that activates as fast as this one.

It takes as little as a 5-hour cycle to absolve into the oil. If you are looking for a quick solution to the oil leaks in your engine, then this product is a great choice.

However, it is advisable to be careful when using this oil leak stop on thin oils as there have been reports of a side effect. This formula is known to thin oils further. This can wear down the engine and reduce performance in the long run when paired with thin oils regularly.

Highlighted Features

  • Rejuvenates rubber seals and gaskets chemically to their original shape.
  • It does not contain harmful solvents that can wear down engines.
  • Very fast activation time – approximately 5 hours.
  • Works with a variety of oils such as synthetic and mineral oils.
ATP AT-205 Re-Seal Stops Leaks, 8 Ounce Bottle
  • Professional strength fast acting resealer, stops leaks fast
  • Rejuivinates all rubber seals & gaskets in engines, transmissions, power steering, differentials and...
  • Compatible with conventional and synthetic oils, ATF, gear oil, power steering fluids and hydraulic...

Lucas Oil 10278 Engine Oil

Lucas Oil 10278 Engine Oil Stop Leak, 1 Quart

Lucas Oils has been a pinnacle of innovation in the oil leak stop market. And that fact is strengthened upon further with the Lucas Oil 10278 Engine Oil. It is safe to say that this additive is one of the most successful and widely recognized solutions in today’s market.

But what makes this formula so desired? You would expect it to do the job of other oil stop leak additives.

While that is true, this particular solution does all of that – but better. Not only that, this is among the only products which actually enhance engine performance and reduces oil consumption.

The oil leak stop remarkably rejuvenates damaged seals and gaskets in its fight to stop possible oil leakages. There are no harmful components in this product so there is no risk of corrosion or damage to the engines.

This product from Lucas Oils can be considered as the best oil leak sealant available today due to it offering no risk but all the rewards. Furthermore, this additive has a unique feature, it increases the pressure of the oil to which it is added – ultimately reducing overall oil consumption in the long run.

The 10278 engine oil supports a variety of oil types including synthetic oils, semi-synthetic and mineral oils, etc. This allows them to strengthen an array of engines such as diesel and gasoline empowered engines.

The activation rate is satisfactory and it is easy to use. However, severely damaged seals and worn gaskets won’t be benefitted by this additive and it is better to seek professional help in that case.

Highlighted Features

  • It does not contain harmful particles in the mixture that cause erosion.
  • Increases oil pressure to reduce oil consumption.
  • Reduces noise produced by the engine.
  • Rejuvenates worn oil gaskets and seals to their original shape.
  • It is compatible with most oil types and engines.
Lucas Oil 10278 Engine Oil Stop Leak, 1 Quart
  • Compatible with petroleum, semi-synthetic and full synthetic motor oils
  • Renews worn seals with no risk of damage or eventual corrosion
  • Reduces engine noise and oil consumption, while raising oil pressure

BlueDevil Oil Stop Leak For Diesel and Gasoline Engine

BlueDevil Oil Stop Leak

BlueDevil is one of the oldest brands around and they are known as one of the top dogs in the market. You can hardly ever go wrong with one of their engine healthcare products. The BlueDevil Oil Stop Leak For Diesel and Gasoline Engine is just another entry in a series of carefully designed additives.

It is constructed with precision to seep completely into the seals of the engine to rejuvenate and revitalize. This repairs worn or damaged seals extensively to stop even the most minute oil leaks. The notable thing about this additive is that it achieves all of that without clogging your engines.

There is not a hint of petroleum distillate or other harmful components in the formula, making it very friendly to the engines. Moreover, it’s a completely safe formula as it poses no threat to people and the environment.

It works fine with synthetic oils, however, using it with semi-synthetic and mineral oils will yield the finest results for this particular additive. In terms of compatibility, the BlueDevil is compatible with both diesel and gasoline-powered engines. It works well with older engines compared to other additives.

There is one slight drawback to this formula, however. Some users have reported that it does not work well with leaky gaskets, so it is recommended to seek professional aid if that problem persists in your engine while using this additive.

The worn seals are repaired permanently – or up until you stop using this additive. Therefore if this product works for your engine, then it would be wise to stick with it in the long run as it offers a lot to the table without drawing any major setbacks.

Highlighted Features

  • It does not contain any harmful chemicals or petroleum distillate.
  • It does not damage or clog up the engine.
  • Rejuvenates and repairs worn seals and gaskets almost permanently.
  • It is safe for people and is environmentally friendly.
  • Works with both diesel and gasoline-powered engines.
BlueDevil Oil Stop Leak
  • Permanently seal seeping or dripping oil leaks
  • Made in United States
  • Package Dimensions : 3.25 L x 6.0 H x 1.0 W (inches)

Bar’s Leaks 1040 Grey Concentrated Rear Main Seal Repair

Bar's Leaks Concentrated Rear Main Seal Repair -...

Bar’s Leaks has always been a very trustworthy and customer-caring manufacturer when it comes to vehicles. The Bar's Leaks 1040 Grey Concentrated Rear Main Seal Repair is another masterclass product from Bar’s that defies expectations when it comes to giving life to seals.

Repairing old worn seals has never been easier. This formula works wonders on the different seals and gaskets, rejuvenating them and chemically restoring their former shape and size. Moreover, the activation rate is fantastic, so you can fix your engine on the go within a short amount of time.

It is very safe and easy to use the product. There are no harmful components to this formula and it’s completely free from petroleum distillate. The health of your engine is in good hands with the leaks 1040 and eventual erosion and engine wear will never be a concern.

This additive is relatively more concentrated compared to other products in the market. This makes the formula surprisingly compatible as it can be applied to a number of synthetic, semi-synthetic and mineral oils without any issue. Both gasoline and diesel-powered engines are supported.

It is the best oil stop leak additive in the market for newer engines. However, older engines don’t react well with the oil stop leak. It is recommended to use this with more recent engines for optimal performance.

Seals are not permanently restored with this additive therefore it is advisable to use it in the long run if you are looking to keep oil leakages in your engine to a minimum.

Highlighted features

  • Rejuvenates seals with efficiency and repairs old worn seals.
  • It does not contain any chemicals that are harmful to your engine.
  • It does not clog up the engine gaskets.
  • Works with almost all sorts of oil types, diesel, and gasoline-powered engines.
  • A very satisfactory activation rate can go to work on the go.
Bar's Leaks Concentrated Rear Main Seal Repair -...
  • Seals timing cover, cam seal, rear main and other hard to stop oil leaks
  • Add to engine oil
  • Specifically designed to seal rear main leaks, but also works better than a conventional stop leak...

Marvel Mystery OilMarvel Mystery Oil MM12R

Marvel Mystery Oil MM12R - 16 Fl Oz. (Pack of 2)

The Marvel Mystery OilMarvel Mystery Oil MM12R is a very unique inclusion in this list. We say so because of its difference in nature compared to other additives we have mentioned. It is more of an engine performance enhancer and a care package other than a complete oil leak stop.

But don’t let that bring doubts into your mind. We called it a care package because it primarily functions for engine maintenance and support.

The additive is constructed to clean out every nook and cranny of your engine from inside and down. It lubricates the insides so your engine performs optimally and removes the chances of valve sticking and clatter.

That’s not all, the fuel to which this additive is used is enhanced drastically. Fuel economy and consumption are reduced alongside engine noise whereas the engine operates much more smoothly. Engine erosion and wear are reduced as well due to this additives cleaning nature.

It is a very safe additive as there are no harmful chemicals included in it – making it viable for older and newer engines alike.

Pair the marvel mystery oil with an oil stop leak from this list and use them in alteration for the finest results. This way, your engines stay clean, smooth and with no risk of wear and oil leakages – increasing the health and performance of the machine over a long period of time.

Highlighted Features

  • Cleans the engines inside and out.
  • Lubricates the valves, reducing clatter and increasing smoothness.
  • Increases fuel efficiency and decreases fuel consumption.
  • It does not contain harmful chemicals for the engine.
  • Works with all types of oil and engines.
Marvel Mystery Oil MM12R - 16 Fl Oz. (Pack of 2)
  • Kit Includes (2) 16oz. Bottles of Marvel Mystery Oil additive
  • Cleans and lubricates fuel injectors and carburetors
  • Reduces and prevents varnish and gum build-up

Bar’s Leaks 1420 Transmission Stop Leak

Bar's Leaks 1420 Transmission Stop Leak - 11 oz.

The brand has quite a lot of experience in the field of automotive products. The Bar's Leaks 1420 Transmission Stop Leak was developed to fix leaks without causing any harmful side effects.

It easily closes any cracks formed by swelling parts such as O rings, seals and gaskets. A small quantity of additive can stop leaks that many products are unable to seal. Even if your car doesn’t have any leaks, using the product makes that much less likely to happen.

In addition to being affordable, the fluid is highly efficient. It gives you the ability to seal different types of leaks with minimal effort. It would be fair to say that the product makes solving leak issues easy. Many users have claimed that this is among the best engine oil stop leak they have ever used.

The versatility of the product is impressive as well. Whether it’s traditional, synthetic or semi-synthetic; it works with all kinds of engine oils. The fact that it can seal cracks quite quickly due to the short activation time acts as a cherry on top.

If you have never used any of Bar’s leak products, you really should try this. We bet you will admire the brand when you notice the effects on the road. If a great product like this doesn’t seem to work, we would recommend a mechanic to check your car as the issue could be more than just a few leaks.

The additive is an inexpensive tool to get rid of the worries of visiting a professional for a long period. It’s formulated by one of the most innovative and research-oriented companies in the automobile products industry as of today.

Highlighted Features

  • Seals most type of cracks and rejuvenates worn seals.
  • Particle-free formulation offers no risk of engine clogging.
  • Works with most types of engine oils, versatile.
  • Highly efficient, only a small amount is to be added.
  • Satisfactory activation time goes to work quickly.
Bar's Leaks 1420 Transmission Stop Leak - 11 oz.
  • Stops and seals transmission fluid leaks
  • Restores gasket and seals to stop transmission fluid leaks
  • Works with all types of transmission fluids

NO LEAK 20401 Engine Oil Stop Leak

NO LEAK 20401 Engine Oil Stop Leak, 16 Fl oz.

The NO LEAK 20401 Engine Oil Stop Leak was launched quite a few time ago. It generated a fan base and has been receiving a lot of feedback and praise for its innovative nature. The company has continually improved the formula over the years. No Leak 20401 is a great example of product evolution.

Generally, oil leaks occur due to shrinkage of engine parts. This formula uses absorbent additives that swell the components back to the original shape, sealing the leaks. Small to medium levels of leaks can be effortlessly stopped by the additive.

In addition to sealing leaks and reducing engine wear, the formula boosts the performance. Such a positive effect is lacking in the products of its competing brands.

Furthermore, it reduces visible smoke from the exhaust. This may look cool to some drivers, but too much smoke is never a good sign.

Instructions on how to use the products are clear and easy to follow. The product is meant for repairing engine gaskets and seals. Therefore, you can’t expect it to work on parts that require replacement.

When you hold a bottle of NO LEAK sealant, you are holding a product that has been repeatedly improved to better serve its purpose. If you still have complaints about the product, you can just send your feedback to the company. Don’t be surprised if they fix the issue in the next modification.

Highlighted Features

  • Boosts engine performance and reduces smoke.
  • Quickly seals sources of small to medium leaks.
  • Easy to follow instructions and safe to use.
  • Reduces engine wear by softening components.
  • Rejuvenates leaky and worn seals to their original shape and size.
NO LEAK 20401 Engine Oil Stop Leak, 16 Fl oz.
  • Stops AND prevents engine oil leaks caused by dried, shrunken, or harden seals
  • Recommended for rear main seal repair
  • Stops smoke and repairs rear main seals

STP 15604B High Mileage Oil Treatment Stop Leak

STP High Mileage Oil Treatment, Formula for Cars &...

Another great ingenious product from STP. The STP 15604B High Mileage Oil Treatment Stop Leak is a two in one package that works as an oil treatment in addition to being a stop leak. This greatly enhances the fuel in your engines to perform better and much more efficiently.

The formula contains zinc ZDDP which acts as an anti-wear catalyst. This lubricates your engines – rejuvenating the worn and leaky seals and gaskets. But it does not stop there, the anti-wear oil coats the insides of the seals and gaskets, preventing damage in the future and keeping your engine healthy.

There are no harmful components in this additive so there remains no risk of erosion and damage.

In terms of enhancements, this oil stop leak from STP acts as nutrition to the oil to increase its pressure and performance while reducing the consumption. It also revitalizes the engine to reduce noise and smoke produced, making it a perfect addition to bigger vehicles such as trucks and SUVs.

The additive works well with synthetic and mineral oils and is compatible with diesel and gasoline-powered engines. It is a perfect blend of class and reliability and with STP, you know you are in safe hands.

Highlighted Features

  • Rejuvenates worn seals and leaky gaskets to their original form.
  • It contains zinc ZDDP that acts as a shield to prevent wear and tear.
  • It does not contain petroleum distillate or other harmful chemicals.
  • Works with synthetic oils, diesel, and gasoline-powered engines.
  • Enhances engine performance, reduces noise and smoke produced.
STP High Mileage Oil Treatment, Formula for Cars &...
  • Rejuvenates seals and gaskets
  • Helps stop leaks, noise and smoking
  • Contains zinc anti-wear agent ZDDP

Lucas 10008 Power Steering Stop Leak

Lucas 10008 Power Steering Stop Leak - 12 oz

The brand is a well-known name in the automotive consumables markets. When it comes to versatility, Lucas is an unsurpassed name.

However, this doesn’t mean you can use the same product for all flow systems. For instance, the Lucas 10008 Power Steering Stop Leak uses a different fluid so engine oil additive to stop leaks will do more harm than good.

For this reason, Lucas manufactures a different product suited for eliminating issues with the power steering unit. The formula is compatible with almost all power steering fluids and can get rid of stubborn leaks. It consists of a mixture of petrol extracts and various oils.

Like the engine, the parts of a steering unit dry up and wear out over time. By revitalizing the components, the formula stops fluids seeping out and closes cracks that were caused by the surface pulling apart. If you feel that the steering isn’t as firm as expected, this could be the sign of a leak.

Lucas pays attention to small details and the proof of this lies in the bottle design. It is small enough to fit in a car’s glove compartment. A pointed tip allows you to easily work pour the fluid. This feature also greatly reduces the chances of spills, which is desirable given the safety hazards of the concentrate.

Solvents in this kind of product have known to have adverse effects. Therefore, Lucas doesn’t include any solvents additive in the formula. Not only that the formulation is free of side effects, but it also enhances steering performance.

Highlighted Features

  • Improves the performance of steering and brake systems.
  • Easy to use and works on the go.
  • It is free of harmful solvents that can damage your vehicle.
  • Reduces wear and tear of steering and braking components.
Lucas 10008 Power Steering Stop Leak - 12 oz
  • Lucas, 12Oz, Power Steering Stop Leak, Removes Hard Spots And Stops Most Leaks Or Your Money Back!...
  • These Are Complete Line Of Heavy-Duty Shop Products
  • Through Creativity, Productivity And Innovation - This Brand Continues To Develop The Finest...

Bar’s Leaks 1010-6PK Engine Oil Stop Leak Concentrate

Bar's Leaks 1010-6PK Engine Oil Stop Leak...

Bar’s Leaks has maintained a good market reputation for a significant duration and is still ranks among the top brands.

The Bar's Leaks 1010-6PK Engine Oil Stop Leak Concentrate can be mixed with 5 quarts of oil. That’s how surprisingly efficient the product is.

This goes hand in hand with its ability to quickly rejuvenate worn seals and gaskets. The aggressive but reliable method makes this the best engine oil stop leak in case other additives bring no results.

This strong concentrate not only repairs worn seals and gaskets but also conditions them for future-proofing that prevents further wear and tear. It is especially friendly to older engines as this formula is more conventional and works well with seals that have been around for a while.

For such a strong concentrate of invasive additive, you would be surprised to hear that this one does not have any petroleum distillate or other substances that can damage your engine. This nature also makes it extremely resistant to clogging the gaskets.

The 1010 pairs perfectly with traditional synthetic oils and support both gasoline and diesel-powered engines.

This is the to-go-to product for users who like to have a more customary solution to leaky gaskets. Its friendly nature to older engines makes it a solid companion for those vintage vehicles.

Highlighted Features

  • Aggressive and reliable oil leak stop solution.
  • Rejuvenates worn down seals and gaskets.
  • Works well with older engines without risk of erosion.
  • It does not contain harmful substances such as petroleum distillate.
  • Compatible with synthetic oils, gasoline, and diesel-powered engines.
Bar's Leaks 1010-6PK Engine Oil Stop Leak...
  • 1 bottle treats 4 to 5 quarts of oil
  • Prevent minor engine leaks
  • Works with all gasoline and diesel engines

What To Consider Before Buying An Oil Stop Leak Additive?

1. Product Quality

When it comes to car products, there are way too many brands to choose from. A majority of these oil stop leak products do more damage to your car than any improvements delivered. For these reasons, the quality of a product is a very important factor to consider.

A cheap formula could clog your car’s engine and cost you a lot more in repairs and replacement costs. Therefore, it is essential to do some research and choose a brand that has a good reputation and positive reviews.

Oil stop leaks are intended for temporary solutions. Products that claim to be able to fix large cracks permanently are false claims.

We recommend that you read the supplier’s instructions carefully and follow them strictly. Most negative oil leak stop criticisms are from customers who haven’t followed the right steps.

A close up shot of a car engine

2. Compatibility

The formula you intend to use needs to be compatible with the engine oil. For instance, a product for petrol engines may not work in a diesel engine.

This is very an important consideration because an unsuited combination of chemicals in the oil and leak stopper could result in clogging. Incompatible oil leak stops can cause severe damage to the engine.

It is also important to check if a product is meant for the circulation system you intend to use it for. For instance, an engine oil leak stopper should not be used in the A/C unit and vice-versa. Products have it labeled on them, what kind of oil it is compatible with and what system it should be used in.

3. Activation Time

The fluid needs to run through the engine for a number of cycles before being fully activated. The time it takes for the fluid to fix leaks after activation is important to consider as you would want to stop the leak as quickly as possible.

Depending on the severity of the leak, you need to choose a suited activation time. A word of advice, you wouldn’t want to leave the engine running for a long time when there is a lot of oil leaking. In such a case you should drive to the mechanic right away.

4. Size And Location Of The Crack

Oil stop leaks are meant for fixing small holes and swelling shrunk parts to reduce or prevent leaking. They are strictly not to be used for larger gaps. Especially because a lot of fluid will leak out before the additive is fully activated.

Even if you do succeed to plug in a large crack, the sealing can gradually lead to accelerating the wear of the system or even cause clogging.

The products are also ineffective in repairing fractures in proximity to rotating parts. This is because the formula needs some time to settle and close the gap. A rotating part prevents the additive from settling properly.

5. Additional Benefits

Some of the best oil leak stop products contain additives that do more than just preventing leaks. Reducing engine noise, boosting performance, preventing corrosion are some of the extra benefits you can expect from products of the top brands in this category.

Products for other systems such as hydraulics, transmission, power steering may also have additives to enhance functionality.

6. Long Term Effects

Some products cause unwanted side effects. For example, some additives can contribute to clogging when used again and again. Another example of side effects is the use of petroleum distillates which restores affected gaskets and seal but increases the wear of the other parts of the engine.

Several other unwanted effects could be caused by the use of an oil leak sealer. We advise that you try to find out about these effects from oil leak stop reviews and other sources that tell you about the harmful effects of the products you considered for usage.

7. Efficiency

An oil stop leak product is not a permanent solution to leaks. Therefore, it is crucial to know how long sealing would last before the leaks start again. Longer lasting additives will save you more cash as you can buy yourself time before you need to go to a car service station.

The amount of additive required is not to be ignored either. The smaller the quantity required to effectively fix leaks, the more efficient an oil leak stop is.

Moreover, not all products can fix cracks in one use. Some require frequent application and this can be more costly and time-consuming overall. An expensive bottle that does the job in one go is better than tens of cheaper ones.

Pouring oil unto the engine

Types of Oil Stop Leak

1. Particle Clogging Formula

This type of oil stop leaks was the first to arrive in the market. The products work by use of additives to close gaps in affected parts of an engine. A formula can consist of one or more of the particle types discussed below.

More additives have been used by companies, the ones mentioned below are the most commonly used in recent times.

A. Ceramic And Metallic Particles

The additive contains ceramic and metallic particles that the high pressure of engine forces into a crack, accumulating and sealing. A disadvantage of this is that the sealed facture return when the oil is flushed.

B. Sealer With Ceramic Fibers

The fibers work in a similar way to additives with other particles. The fibers attach to the cracks and form a mesh-like entanglement. When the mesh hardens it forms a sealing that isn’t affected by an oil change.

C. Sodium Silicate

Sodium Silicate is in liquid gaseous form and is effective for sealing leaks in the hot parts of the engine. The high temperature melts sodium silicate closing the gap. This type is generally used in combination with metallic particles for greater effectiveness.

2. Absorbent Formula

As the name suggests, the formula is absorbed by gaskets and seals.  This a newer generation formula that does not contain any kind of particles. Revitalization of the parts is achieved by this mechanism without the risk of clogging.

Initially, petroleum distillates were used in these formulas. Currently, different chemicals are preferred instead, as the petroleum products were known to accelerate engine deterioration. This type of formula is the most sold in the current market.

3. Combination Formula

The third type used both the aforementioned ones to provide better effectiveness than either of them. Such a product can fix slightly larger holes.

These additives are considered to be the best engine oil stop leak additives and thus are believed to be the most effective of the three types.  Such a formulation can plug in larger cracks without the risk of clogging the engine.

Top-Rated Oil Stop Leak Brands On The Market

Bar’s Leaks

This 70-year-old U.S. based company has sharpened its tools to provide its customers with the finest products for their car engines. It employs several experts and spends a lot of research each year.

It strives to create better and more efficient formulas as the oil stop leaks are the main products of the brand.

A man under the vehicle fixing an engine


ATP initially only sold replacement components. The company later evolved into a brand that sells high-quality sealers.

Most of their products come with additional benefits. One such benefit is rust and corrosion protection. ATP’s products do a really good job in engine maintenance. Therefore, users prefer to use them even when their cars don’t have any leaks.

No Leak

No leak is a premium product series under the brand Golden Eagle. The products are versatile and have high safety standards.

Known for their attempts to recruit the finest petroleum scientists and engineers, the company built a crew of experts that strives to make their products more efficient and long-lasting.

Lucas Oil

Founded by Forrest Lucas and his wife Charlotte, the company started its journey in 1989.

The oil stop leak products supplied by the brand are especially well known for the versatility of use. They are compatible with petrol, semi-synthetic and fully synthetic oils. Furthermore, the products can be used on engines of small cars and large trucks, old or new.

This brand excels compared to the rest in terms of engine performance enhancement because almost all of their products increase the pressure of the oil to which this is applied to.

Marvel Mystery Oil

Marvel Oil Company has maintained the trust to several generations of car enthusiasts. Butt Pierce established the brand during the post-world-war I era. It produced carburetors for the majority of American cars back then.

The founder is credited with the invention of a mixture of chemicals and oils, which he called a mystery.

Frequently Asked Questions

1. Can I Use Oil Stop Leaks for Fixing Cracks in the A/C Unit?

The additives used for closing gaps in the refrigeration unit works in a different manner. It’s recommended that you use a leak stop that is suited for refrigerants. You should also note that using stop leaks in refrigeration unit contaminates it and would cost you more for the next repair.

2. How Do I Tell There Is Oil Leaking From My Car?

If you notice dark puddles under your car, it’s likely that there is a leak. Having to change the oil more often than usual is another indication. A sign you can look for is blue smoke. The color of smoke may be hard to notice but this smoke also produces a smell.

A very strange strong smell is the most obvious sign of a leak. This smell could be due to the leaked oil burning or overheating of the engine.

3. How Do I Prevent Cracks From Occurring?

Cracks occur as the surfaces of engine parts become dry over time. The best way to keep the engine in good condition is to use fuel with high-mileage. The cost is higher per gallon but it significantly changes your engine health in the long run.

4. How Long Can I Drive With Oil Leaking?

You should try to fix the problem at the earliest possible. A small amount of leak may not cause significant damage to the engine.

However, it leaves you at the risk of oil levels running too low without your knowledge. In such cases, the engine could overheat and be seriously damaged.

Another strong reason why you shouldn’t ignore this is that there is always a risk of fire from the leak, which can cause the engine to fail. A failed engine would cost a huge sum to repair or may even require replacement.

A man standing under the vehicle'

5. How to Use an Oil Stop Leak and What Quantity Should I Add?

The instructions to follow and the amount to be applied is mentioned in the manual by the manufacturer. It is important that you stick to the guide as an improper ratio of ‘oil to additive’ can have adverse effects.

If it is instructed that you only add a small amount, then this is an indication that the product is of high quality.

It is wrong to think that adding more quantity will seal the cracks faster. The time to fix leaks is dependent on the activation time. The best advice we can give is to follow the instructions on the package very strictly.

6. The Leak Does Not Stop, What Should I Do?

If you notice that the leak persists even hours after the activation time of the product mentioned, then that is something to note. It is recommended to not try another product or reuse the one you used before.

Try to locate the source of the leak yourself to see the size of the crack. If nothing works, go to the mechanic and get it fixed. Oil leak stops can be illustrated by an example of cloth patches, they work for a while but eventually, you need to buy new clothes.

7. Are Oil Stop Leaks Safe to Use?

Most of the products are concentrated and therefore, they must be used with extreme precaution. We advise that you wear protective clothing, safety goggles and gloves while using a formula. If the product comes in contact with your skin or eyes, seek immediate medical attention.

Another safety measure to take is to turn off the engine before. This is because the engine and its contents can get hot. There is also a risk of fluid spilling out due to pressure if not given time to cool down.

8. When Should Oil Stop Leaks Be Used?

There are no restrictions as to when you can use the formulation, as long as you don’t overuse. Additives can be used regularly to prevent cracks from occurring in the first place. Many top brand products have other positive effects such as performance boost or noise reduction.

However, you shouldn’t attempt to fix major leaks. The appropriate thing to do in such a case is to take your car to a mechanic right away.

9. Are Oil Stop Leaks Harmful?

The answer is that it depends on several factors. Quality matters most. A product that has low efficiency, or contains additives that can lead to clogging or increase the wear of engine parts is not what we would recommend.

Secondly, the size and location of the leak need to be considered. Large cracks can’t be closed by additives. Cracks formed near rotating parts are immune to these stop leaks as well.

10. Does Using a Leak Stopper Mean That I Don’t Need to Visit a Mechanic Anymore?

The purpose of these products is to stop oil seeping out by swelling shrunk parts such as gaskets.

Initially, the formulas used additives such as particles to close cracks. As these have negative effects such as engine clogging, modern formulas are absorbent and work by revitalizing engine components. This process closes gaps as the parts swell back to their original sizes.

However, if you see that the problem still persists after applying these leak stoppers, you’ll need to visit a professional mechanic.

A mechanic standing under the vehicle fixing an engine

Final Words

The health of your engine does matter and you would preferably like to keep it in top shape. Seals and gaskets do tend to show signs of wear eventually, but with proper moderation and care, these problems go away. The best oil stop leak further enhance your engine to perform at its fullest.

We highlighted some factors that one ought to take into consideration before buying the right additive. We have also recommended what we think are the finest additives in today’s market in terms of efficiency and quality.

We hope that this guide acts as a one-stop solution to put an end to the mishaps in your engine and help it get back to working condition in no time.