Best Head Gasket Sealers: Permanently Solve Coolant and Engine Oil Leak Problems
Permanently seal cracks and coolant leaks with our top picks for the best head gasket sealer.
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BY Noelle Talmon / LAST UPDATED ON September 21, 2021
Nobody wants to experience a blown head gasket. This type of malfunction can cause a lot of issues, including engine misfires and oil leaks. You can choose to replace the entire head gasket or you can use a head gasket sealer instead. It's a much cheaper alternative, and depending on the circumstances can do a great job of correcting the problem. There are numerous head gasket sealers available online and in stores, so it can be hard to choose the best one for your needs. Check out some of the top options in our buying guide below.
An easy-to-use product that works well with both diesel and petrol engines. It’s a multi-use sealant that solves problems associated with head gasket leaks, heater core, and freeze plugs.
- Easy to work with
- Helps eliminate overheating problems
- Improves vehicle mileage
- Reduces smoke emissions and oil consumption
- Works well for old trucks that cannot hold water
- Backed by a 100 percent money-back guarantee
- Will only work well if you flush the engine first
An affordable sealant known to solve common problems fast and blends easily with antifreeze. Can eradicate tapping or flushing and repair other problems such as freeze plugs, heater cores, warped gaskets, and cracked heads.
- Permanent solution to coolant leak repairs
- Mixes well with all antifreeze
- Doesn’t require engine flushing or draining
- Fixes multiple problems
- Comes with a friendly price tag
- Sealant might not work well if the head gasket has extensive damage
- Discolors some brands of antifreeze
A head gasket sealer that is compliant with ASTM standards and permanently seals the blown head gasket on all types of engines. The sealer is safe and easy to use.
- Sealant is a permanent solution that works well during any weather condition
- Prevents coolant leaks
- Prevents the loss of radiator fluids
- Helps with resolving cold start rough idle
- Manufactured by a reputable company
- You may have problems with the thermostat after using the product
- May block the cylinder tubes and passages
Why Trust Us
Our reviews are driven by a combination of hands-on testing, expert input, “wisdom of the crowd” assessments from actual buyers, and our own expertise. We always aim to offer genuine, accurate guides to help you find the best picks.
Benefits of Head Gasket Sealers
- Fix leakages in blown head gaskets. A blown head gasket is a big problem especially when you are traveling. Most people would opt to have a professional look at the head gasket, and that would translate to wasting a couple of hours as the issue gets fixed. With a high-grade sealant, you could permanently stop the leakage and prevent your engine from misfiring.
- Save money. Head gasket sealers are not as expensive as having the head gasket completely replaced. A replacement would require you to buy the head gasket, and you would also have to pay the automotive mechanic that handles the task. A head gasket sealer is an inexpensive option that provides a permanent solution, just like the replacement.
- Multi-purpose product. A good gasket head sealer will not only help solve issues related to the head gasket; some of these products can be used on other leaks that might affect the performance of your engine. A high-grade sealer can also help solve problems related to the heater core and bad freeze plugs.
- Time-saving. Unlike completely replacing the head gasket, using a sealant is an easy process. You just pour the sealant into the radiator cap, and it flows through the entire system discovering the leaks. The process is fast, and the leaks will be sealed in under an hour.
BlueDevil is a company that manufactures professional grade sealants for the automotive industry. The company supplies its products to over 400 distributors located across North America, South Africa, Asia, Europe, and South America. BlueDevil started selling its products in 1997 and is currently headquartered in South Carolina. The company manufactures some of the best head gasket repair additives, and the BlueDevil Head Gasket Sealer is one of its popular products.
ATP Automotive is a renowned automotive products manufacturer that has been in existence since 1955. The company has a 2,000 square foot state-of-the-art facility in Chicago, where it makes top-of-the-line aftermarket replacement parts and car care products for automatic transmissions. Consider trying out the ATP AT-205 Re-seal, which only seals minor leakages in the head gasket.
K-Seal is an international company that manufactures and distributes sealants around the world. The company prides itself in its ability to sell millions of sealant bottles every year. It’s currently based in New Jersey. The K-Seal Ultimate Head Gasket Repair is one of the cheap head gasket sealers manufactured and distributed by K-Seal company.
Steel Seal is a sealant manufacturing company that focuses on making and selling head gasket sealers. The company has been in business since 1999 and has provided mechanical solutions to hundreds of thousands of mechanics and car owners. Steel Seal is headquartered in the United Kingdom. The Steel Seal Blown Head Gasket Fix Repair Sealer is one of its best head gasket sealants.
Based in Solon, Ohio, Permatex produces a wide variety of automotive maintenance and repair products, including gasket makers, sealants, adhesives, cleaners, and lubricants. We recommend the Permatex High Tack Gasket Sealant.
Bar's Leaks products are formulated and manufactured near Detroit, Mich. The company has been helping car owners tackle repair leaks for more than 70 years. Check out the Bar's Leaks Block Seal Permanent Head Gasket Fix.
Best Head Gasket Sealer Pricing
- Under $20: This price range includes head gasket sealers that come in small containers weighing under 16 ounces. The content of these containers can help you handle leakages associated with the head gasket effectively, though you might have to get a bigger container for larger engines.
- $25-$50: If you are looking for a larger container that can fix a couple of leaks, then look into products in this price range. The containers typically have 32 ounces of fluid. That’s enough to handle six- and eight-cylinder engines.
- $50 and up: In this price range, you will find premium products. These are sealers that can fix cracked head gaskets permanently and are from reputable brands. The quantity is also enough to deal with larger engines such as six-cylinder engines and more.
The quantity of the sealant is measured in ounces. The quantity ranges from 8 ounces to a couple of gallons. Buy a sealant that’s enough for your problem. For smaller engines, the 16-ounce container is enough to seal a blown head gasket and will allow you to get to your destination. It’s also a good idea to have a small container for emergencies.
Ease of Use
Dealing with a head gasket leakage is as easy as pouring the sealant into the radiator. However, other issues may arise, and you may need to have some technical knowledge of the sealing process. Ensure the product you choose is easy to use and comes with clear instructions on how to seal different leakages.
- Type of Engine. The main types of engines are diesel and gasoline engines. These engines might require different types of sealants. When buying a high-grade sealant for your head gasket, make sure you check on the advantages the product has for your engine type.
- Action Time. After pouring the sealant, you cannot use your vehicle for a certain period of time. You, therefore, need to know how long you have to wait out for the sealant to settle down. Most take about an hour or more depending on the size of your car’s radiator capacity.
- Functionality. There are products that are designed to solve different leakage problems in the engine. Though you might have a head gasket problem, you can find a sealant that can fix that and also perform many other tasks. Make sure you read the product description to understand what else the sealant can do.
Best Head Gasket Sealers Reviews & Recommendations 2021
- Make sure the product works with your antifreeze. Some head gasket sealer brands are not compatible with certain types of antifreeze. Read the instructions, and make sure it's safe to use with the antifreeze in your vehicle.
- You can either completely replace a blown head gasket or try to use a sealant to repair it. Sometimes a sealant will do the job, and sometimes you need to invest in a new head gasket. If the part is old and too damaged, a sealant will probably not correct the problem, so don’t waste your time and energy on a product that won’t likely work.
- If you think your vehicle has a blown head gasket, stop driving it. The oil will mix with the coolant, which will cause your car or truck to overheat and misfire.
Q. Are head gasket sealers safe for the engine?
Good-quality head gasket sealers are designed to work effectively without compromising the engine. Most sealants have been tested and known to work well with either diesel or petrol engines and with different materials such as plastic, aluminum, and cast iron.
Q. Are head gasket sealers better than complete gasket replacement?
This depends on the level of damage you are dealing with. Most head gasket sealers provide a permanent solution to minor leakages. They will, however, only offer a temporary solution to severe leaks, and eventually, you might need a complete gasket replacement.
Q. How long will the head gasket sealer last after application?
Different brands have different qualities and while some will last long, others will not. It also depends on the severity of the damage to your head gasket. Most sealants offer permanent solutions to minor leaks but can only last for a maximum of six months if the damage is severe.
Q. Will the sealant clog other holes in the system?
Sealants are designed to fill up small holes in the head gasket. Most, however, can also clog up leaks in the transmission, power steering, and hydraulic systems. If you are dealing with bigger holes that the sealer cannot handle, you should think about replacing the head gasket.
The Steel Seal Blown Head Gasket Fix Repair Sealer is our top pick for the best overall permanent head gasket sealer. It works well on older and new vehicles and is suitable for cars, vans, SUVs, and trucks.
If your budget is a little tight and you still need a professional-grade sealer, check out the K-Seal ST5516 HD. It’s an affordable sealant that comes with most of the qualities you can find in more expensive brands.