Best Oil Leak Stop [2021 Review]

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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 the best oil leak stop solves most of these said issues. When it comes to choosing the perfect remedy for your problem, things, however, can get a bit trickier.

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:

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

Our Top Oil Leak Stop Reviews

ATP AT-205 Re-Seal Stops Leaks

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

The ATP AT-205 Re-Seal Engine Oil Stop Leak is an 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 engine oil stop leak solution, then this product is a great choice.

However, it is advisable to be careful when using this engine oil stop leak 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

The Lucas Oil 10278 Engine Oil 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 engine oil stop leak additives.

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

The engine oil stop leak 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

The BlueDevil Oil Stop Leak For Diesel and Gasoline Engine 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.

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 -...

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

Seals are not permanently restored with this engine oil stop leak 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.
Sale
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 oil stop leak 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.

It is a very safe engine oil stop leak 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 engine 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 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 engine oil stop leak 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.

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 uses absorbent oil stop leak 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 oil stop leak additive formula boosts the performance. Such a positive effect is lacking in the products of its competing brands.

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

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.
Sale
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 &...

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.

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 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.

Solvents in this kind of product have known to have adverse effects. Therefore, Lucas doesn’t include any solvents  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...

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 oil stop leak 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.

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 Engine Oil Stop Leak Additive?

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.

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.

Size And Location Of The Crack

Engine 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 engine oil stop leak 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 engine oil stop leak additive from settling properly.

Long Term Effects

Some products cause unwanted side effects. For example, some oil stop leak 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.

Efficiency

An engine 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 oil stop leak 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 engine oil stop leak 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 Engine Oil Stop Leak

1. Particle Clogging Formula

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

2. Absorbent Formula

As the name suggests, this engine oil stop leak 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 engine oil stop leak type is 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.

A mechanic standing under the vehicle fixing an engine

Final Words

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.