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Oil stop leaks are designed to stop and seal leaks caused by general wear and tear in your vehicle’s engine. Over time, the engine’s gaskets and seals will start to degrade, and you will have to repair it. The good news is that a high-quality oil stop leak is a relatively easy solution for certain issues. It can stop leaks as well as prevent them from occurring. There are many options available in stores and online, so it can be challenging to choose the right one. Keep in mind that these products are great temporary solutions. They do not replace the need to address faulty components, and may not work at all when an issue is outside of their reach. That said, they will buy you valuable time between now and when you actually have time and resources to perform necessary repairs.
Summary List
- Best Overall: Lucas Oil 10278 Engine Oil Stop Leak
- Best Value: ATP AT-205 Re-Seal Stops Leaks
- Honorable Mention: Liqui Moly Oil Leak Stop
- Best Quantity: Lucas Oil 10279 Engine Oil Stop Leak 1 Gallon
- Best Value Runner-Up: Bar’s Leaks Oil Seal
Our Methodology
Oil stop leaks are something we’ve all spent plenty of money on. Over the years, we’ve developed a good sense of what’s good and what isn’t. Still, we’ve taken the time to do the homework and see what the rest of the world has to say. By reading real customer reviews and dissecting product descriptions, we are able to confirm that anything on this list is worth your consideration.
Best Oil Stop Leak Additives: Reviews & Recommendations
Best Overall: Lucas Oil 10278 Engine Oil Stop Leak
Lucas Oil is known for making reliable products. If you’re looking for an oil stop leak that works without costing too much, they have the perfect solution. The 10278 Oil Stop Leak is excellent for stopping leaks and boosting your performance. This product does not contain any harmful solvent or any corrosive properties. That means using this product won’t have any long-term effects on your engine. It’s the only additive that actually improves your engine’s performance. The successful resealing of your fuel system will reduce engine noise and oil consumption While some additives can dilute your oil, Lucas manages to increase oil pressure, which is how you’ll see your performance boost. Similar to other stop leaks, Lucas uses chemicals to recondition deteriorated seals. It is compatible with all types of engine oils, including full synthetic oils. Lucas is a financially smart option that consistently gets great engine oil stop leak additive reviews.
Much like all of the products on our list, Lucas Oil Stop Leak Additive isn’t going to be able to fix every issue. Some holes are too big for the revitalized gaskets to seal correctly. Depending on what kind of seal issue you have, expanding the gaskets may have an adverse effect. Also, Lucas isn’t compatible with diesel engines.
Best Value: ATP AT-205 Re-Seal Stops Leaks
eWhat is the best engine oil stop leak? Look no further than the AT-205. This universal oil additive works incredibly fast and covers the widest range of fuel systems. Plus, the product is surprisingly cost effective when used with smaller oil leaks. ATP makes the most comprehensive oil stop leak available. This product works with both gasoline and diesel engines. It is also compatible with all oils, including conventional, synthetical, and fully synthetic. It even stops leaks in other systems like transmission, hydraulic, and power steering systems.
This product is the best engine oil sealer. This is due to ATP’s focus on revitalizing the rubber seal throughout the engine. The formula uses plasticizers to reshape and fix the rubber-based gaskets chemically. This chemical works great, and it is the same substance used to make the rubber flexible in the first place. ATP guarantees that AT-205 will start working in just five hours. You need to pour it in with the engine oil—be sure to follow the correct measurements. You can add it at any time in between oil changes without prep work.
While the formula works excellent at rejuvenating rubber, it isn’t perfect for every oil leak situation. ATP has the possibility of thinning out your oil. This depends on what type of oil you use, but thinner oil can cause issues such as lower performance and worse gas mileage. It’s also possible for this product to produce blue smoke.
Honorable Mention: Liqui Moly Oil Leak Stop
Liqui Moly is a brand that finds itself in everyone’s garage, and this stop leak is a prime example of why that is. It’s a stop leak that handles multiple jobs at once. Alongside stopping leaks, as the name suggests, it can also significantly reduce engine noise. It’s also compatible with manual transmissions, making it among one of the more versatile solutions for some motorists.
The main problem with this product isn’t its ability to get the job done; it’s the price. This is one of the most expensive options on the market. It’s also worth noting that it will not work for automatic transmissions or motorcycles with wet clutch systems, and owners of those vehicles will put the extra money toward something more reasonable for their situation.
Best Quantity: Lucas Oil 10279 Engine Oil Stop Leak 1 Gallon
Lucas Oil takes a second spot on our list with what is essentially the same product as the first. This stop leak is a strong contender for its ability to handle all kinds of leak sources, including the rear main seal in your engine. It can also help the fuel system to a small degree, is useful for a variety of engines, and can even boost oil pressure for added benefits. The added benefit of this particular option is that it’s a gallon, which is great for owners of multiple vehicles that have a long list of small leaks to deal with.
Of course, the added expense of the full gallon simply isn’t worthwhile for many vehicle owners. It’s also limited to gas engines, as is the pick for Best Overall, meaning diesel owners will have to look on for their leak solution.
Best Value Runner-Up: Bar’s Leaks Oil Seal
What’s a stop leak round-up without Bar’s Leaks product? Bar’s Leaks Oil Seal is an excellent, affordable solution for small oil leaks. It’ll handle main seals, leaky gaskets and even valve seals and guides. So not only is it affordable, it’s super versatile. Of course, it will work for both gasoline and diesel applications. It’s also made in the USA, which is a nice bonus.
The biggest drawback to this product is the fact that the money-back guarantee is a hollow claim to those who’ve tried to use it. Of course, we can’t expect stop leaks to work miracles, but it’s probably better not to expect you to get your money back if this doesn’t seal a leak.
Our Verdict on the Best Oil Stop Leak Additives
If you’re looking for universal protection, then Lucas Oil 10278 Engine Oil Stop Leak is the best engine oil stop leak product on the market. Customers who want to stop leaks and save money should use ATP AT-205 Re-Seal Stops Leaks.
What to Consider When Shopping for Oil Stop Leaks
While the list above is certainly good enough for most, it doesn’t give you the tools you need to make an educated decision. There’s a lot to consider when shopping for oil stop leaks, and this buying guide is here to help you familiarize yourself with them. After reviewing it, you’ll have a much better idea as to of which works best for your situation.
Types of Oil Stop Leak
Particle-Clogging Formulas
Initially, motor oil leak sealers were designed to clog the hole where oil was escaping. Each company had its own way of doing this—some of the earliest formulas used ground peanut shells as a block. The ground particles would flow to the leak and clog the area to save oil. The problem with these particles (as well as formulas that use sawdust, aluminum shavings, and other additives) is the long-term effects on a motor. They increased engine wear and would eventually do more harm than good.
Absorbent Formulas
The best engine oil stop leak additives you can buy are made to absolve into all the seals in the engine. Since these formulas do not have engine clogging particles, they don’t come with the same harmful effects. The solvents expand and rejuvenate the gaskets and components to their original size and flexibility, so any leaks caused by gaps or deteriorated seals will once again be closed. Older formulas used petroleum distillates to achieve this result. Newer stop leak oil treatments use different chemicals as the distillate can further deterioration in the engine.
Key Features
Plasticizers
Since the most common cause of an oil leak is gaps between the various seals, having a stop leak additive that rejuvenates the seals is essential. This is usually a chemical process that will bring cracked rubber pieces back to their original sizes. Each company will have a different way to achieve this, but chemicals that are most effective are called plasticizers.
Petroleum Distillates
A common chemical used to revitalize gaskets is petroleum distillates. The issue with this chemical is that it can have adverse long-term effects on your engine. It can wear out parts of your fuel system while it works to fix others. Over time, this can become more expensive than the original issue. Petroleum distillates are something you want to avoid in a good stop leak additive.
Oil Stop Leak Pricing
For under $25, you can get any of the best engine oil stop leak additives in small quantities, like 8 ounces and 24 ounces. Spending more often means getting a larger bottle or even a multi-pack. However, the cost of stop leak can quickly surpass the cost of a repair. If you find yourself buying bulk for a single engine, it might be worth reading into what it would take to buy the replacement seal and to install it.
FAQs
Oil stop leaks are easy to use. Simply mix it with the oil you traditionally use in your car or truck. Make sure to properly measure the amount you need. You can find this information on the container of the stop leak fluid.
Some old-fashioned oil stop leaks were not good for engines. Modern technology has caused the creation of better formulas, so today’s products should work just fine. However, if you use the wrong oil stop leak, it can cause engine damage, so make sure to do your research and choose the proper additive.
Oil stop leaks are a great solution, however, they aren’t designed to fix all issues. Should you use a product and don’t notice an improvement, take your vehicle to a mechanic so he can properly diagnose the problem.
Maybe. That depends on what is causing the oil leak. Oil stop leaks are designed to revitalize gaskets and seals to minimize gaps that cause leaks. However, if you have a large hole or a lot of engine damage, an oil stop leak will not solve the problem.