Best Head Gasket Sealer 2020

Head gasket failure is one of the most common engine problems. There are tell-tale symptoms that the head gasket is failing, such as coolant or oil leaks, blue exhaust smoke, engine overheating, and cylinder misfire. If you notice any of these symptoms, you should fix it immediately with the best head gasket sealer. Here are the best head gasket sealers in 2020. 

The Best Head Gasket Sealers

Bar’s Leak Head Gasket Repair 

(Best Overall)

Bar’s Leak Head Gasket Repair is perfect for cars that overheat quickly. You don’t need to drain the coolant system before or after using the sealer. It doesn’t matter whether the coolant system contains water or antifreeze. You can mix the sealer with the content of your coolant system. 

If the coolant system is dirty or there are existing blockages, you need to flush it beforehand. Bar’s Leak Head Gasket Repair can bond to iron, cast iron, aluminum, plastics, and copper. It contains carbon fiber particles and sodium silicate. You can use your car again in less than forty-five minutes.

Key Features:Specifications:
★ Seals radiator leaks, cracked cylinder heads, and heater core 
★ Fixes blown head, intake gasket leaks, core plugs, and leaking freeze
★ The patented solution reduces overheating as the sealant circulates 
★ Brand – Bar’s Leaks
★ Model – HG-1
★ Weight – 2.65 pounds


  • can be used on bubbly radiators and cars that overheat fast
  • effective on bigger engines
  • seals mild and moderate leaks for a long time


  • sealer takes a long time to pour due to its thick consistency 
  • can clog heater core or radiator if not flushed 

Steel Seal Blown Head Gasket Fix Repair Sealer 

(Best Value)

Steel Seal Blown Head Gasket Fix Repair Sealer helps fix cracked heater cores, heads, and freeze plugs. The liquid gasket is easy to use and versatile. It also comes with a money-back guarantee, so you can ask for a refund if you’re not happy with it. 

Key Features:Specification:
★ Ideal for 6 cylinder engines
★ Comes with a money-back guarantee
★ Permanently seals head gasket cracks
★ DIY pour-in mix 
★ Brand – STEEL SEAL
★ Weight – 2.2 pounds


  • works fast
  • clear instructions
  • will not clog or damage the coolant system


  • expensive 

K-Seal Multi-Purpose One Step Permanent Coolant Leak Repair 

(Premium Pick)

K-Seal Multi-Purpose One Step Permanent Coolant Leak Repair can be used immediately. You only need to shake the bottle and pour the mixture in. There’s no need to flush or drain it after. You can start your car and be back on the road right away. It can be used to fix the water pump casing, water pump casing, engine block, and cylinder heads. K-Seal comes with a PDF guide that describes engine problems as well as how to use the product optimally.

Key Features:Specification:
★ Supports 12 cylinder engines 
★ Compatible with all kinds of antifreeze
★ Ceramic formula
★ Comes in an 8-ounce bottle 
★ Works within 1 to 3 minutes
★ Brand – K-Seal
★ Model – ST5516
★ Weight – 1.2 pounds


  • can be mixed into the coolant system without any problems
  • versatile
  • works with antifreeze
  • shake, the pour-n-go formula makes it easy to use 


  • discolors some antifreeze brands

BlueDevil Head Gasket Sealer

BlueDevil Head Gasket Sealer doesn’t have any particulates or solid matter. Its main ingredient is sodium silicate, so it doesn’t cause additional wear and tear to the system. In order to use the liquid sealer, you need to drain the coolant system and get rid of the thermostat to make sure that the product circulates properly. 

BlueDevil Head Gasket Sealer is also capable of bonding to almost any material. It is durable, so it will last for a long time. 

Key Features:Specification:
★ An alternative solution for time-consuming and expensive gasket repairs 
★ Doesn’t contain any particulate or solid matter that can damage the car engine
★ Provides a permanent repair 
★ Brand – BlueDevil Products
★ Model – 38386
★ Weight – 2 pounds


  • easy to use and provides a permanent fix 
  • bonds to various materials
  • doesn’t contain harmful chemicals
  • can be used to treat common symptoms of blown head gaskets


  • not ideal for larger engines
  • the cooling system needs to be rinsed several times 

K&W Head Gasket & Block Repair 

K&W Head Gasket & Block Repair uses nanotechnology to seal hard surface areas as well as boost its load-bearing capability and tensile strength. Gaskets need to endure pressure, and by using K&W Head Gasket & Block Repair, you can avoid expensive gasket replacement. 

Key Features:Specification:
★ Compatible with both diesel and gasoline engines
★ Comes in a 32-ounce bottle 
★ Can be used to fix 8, 6 and 4 cylinder engines 
★ Brand – K&W
★ Model – 401232
★ Weight – 2.6 pounds


  • perfect for those who love DIY 
  • seals small leaks long-term
  • can be used to deal with early signs of a damaged head gasket
  • easy to use


  • misuse can damage the engine 
  • it takes 15 hours to settle down

BlueDevil Pour-N-Go Head Gasket Sealer 

BlueDevil Pour-N-Go Head Gasket Sealer is perfect for those with 6 or 4 cylinder engines as it can permanently seal cracked or blown head gaskets. This can help you save money since you don’t need to replace the gasket too soon. Some people use the product to fix external leakages in their radiators. 

Key Features:Specification:
★ Pour-n-go formula 
★ Permanently seals leaking, blown or cracked head gaskets
★ Used for v-6 and 4 cylinder engines
★ Brand – BlueDevil Products
★ Model – 00209
★ Weight – 1 pound


  • easy to use
  • ideal for single repair fixes 
  • permanent 


  • not ideal for boxer engines 

ATP Re-Seal Stops Leaks 

ATP Re-Seal Stops Leaks can be used to fix various trouble areas such as cracked rubber seals, transmission, and gaskets. You can also solve the power steering system problems. Since ATP Re-Seal works with various engine fixing chemicals, there won’t be any contradictory reaction. This is particularly useful if there’s engine oil or gasoline leaking from the vehicle. These chemicals won’t dissolve ATP Re-Seal. 

Key Features:Specification:
★ Revitalizes rubber gaskets and seals in the engine, differentials, power steering, hydraulic systems and transmissions
★ 6-quart capacity
★ Contains no petroleum distillates, so it won’t break down seals
★ Works with synthetic and conventional oils, power steering fluids, ATF, hydraulic oil and gear oil
★ Brand – ATP Automotive
★ Model – AT-205
★ Weight – 1.76 ounces


  • compatible with all kinds of oil
  • no flushing or draining required 
  • clears sludge and conditions seals
  • can be used to deal with other kinds of leak
  • lasts for a long time


  • it takes a long time to seal leaks
  • can make oil stickier 

Permatex Gasket Maker 

Permatex Gasket Maker forms an elastomeric material in place, which is more durable and reliable than a pre-cut gasket. It’s blowout resistant and resists various shop fluids such as oil, coolant, and ATF. 

Permatex Gasket Maker is also fleet-tested and sensor-safe. It can be used to fix thermostat housings, marine, automotive and heavy-duty gaskets, gearbox covers, thermostat housings, valve covers, and pumps.

Key Features:Specification:
★ Seals immediately, creating a durable elastomeric gasket and eliminating the need for rubber, cork, formed, paper or pre-cut gaskets
★ Blowout resistant, protecting the engine against seepage and leaks caused by thermal expansion and vibration 
★ Temperature range – 500°F (intermittent); 75 to 450°F (continuous)
★ Brand – Permatex
★ Model – Right Stuff Power bead Gasket Maker – 7.5
★ Weight – 9.6 ounces


  • high oil resistance
  • great flexibility makes it ideal for old engines 


  • vague instructions 

K&W FiberLock Head Gasket & Block Repair 

K&W FiberLock Head Gasket & Block Repair has an easy pour-n-go formula that can be used to fix cylinder heads, engine blocks, head gaskets, and cooling systems. It boasts 3 technologies – nanotechnology, Cool-X conditioner, and military-strength fibers. K&W FiberLock also works with plain water and all antifreeze brands. 

Key Features:Specification:
★ Can be mixed with all kinds of antifreeze
★ Works within 15 minutes
★ Comes in a 32-ounce bottle
★ Works with diesel and gasoline engines
★ Brand – K&W
★ Model – 401224-6
★ Weight – 2.5 pounds


  • included conditioning agent regulates temperature
  • seals small and large leaks
  • easy to use 


  • applications have to be repeated for major leaks

Steel Seal Head Gasket Sealer for 4 Cylinder Engines 

Steel Seal Head Gasket Sealer for 4 Cylinder Engines boasts a triple-patented green liquid formula that permanently seals cracked heads or blown gaskets. If you are not satisfied with the product, you can get a refund because it comes with a money-back guarantee. You can also use it to fix freeze plugs and heater cores. It’s quite expensive, but it does a decent job of fixing leaks. 

Key Features:Specification:
★ Triple-patented formula
★ Provides a permanent DIY pour-in solution to blown head gasket leaks
★ Perfect for 4 cylinder engines
★ Brand – STEEL SEAL
★ Model – 4CYL001USA
★ Weight – 1.35 pounds


  • comes with a money-back guarantee
  • easy to use
  • quick-acting, helping you save a lot of time 


  • expensive 

Best Head Gasket Sealers Buying Guide & FAQ

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The best head gasket sealer can help prevent permanent damage to your car engine. However, you should be careful when buying a gasket sealer. You need to assess its efficiency, durability, and workability. Read this guide and learn what you should consider when buying the best head gasket sealer. 

Why Do You Need Head Gasket Sealers?

If your head gasket is damaged, you can fix it with a head gasket sealer. It can also improve your car’s performance in only an hour. You only have to pour the sealer in the gasket then wait for thirty minutes. Here are the benefits of the best head gasket sealer. 

  • Save Money – A head gasket sealer is cheaper than head gasket replacement. It offers a permanent solution at a much lower price. 
  • Fix Leaks in Damaged Head Gaskets – Taking your car to a professional just to get the head gasket inspected is time-consuming. When you have the best head gasket sealer, you could fix leaks and prevent the engine from misfiring. 
  • Multi-purpose – You can also use the sealer to deal with other leakages that are affecting the engine’s performance. It can be used to fix bad freeze plugs and heater core plugs. 
  • Save Time – Using a head gasket sealer is easier than replacing the gasket. 

What to Look for When Buying Head Gasket Sealers

Here are some of the things that you should look for in a head gasket sealer. 

  • Easy to Use – Make sure that the sealer is user-friendly. It should have clear directions on how to fix different kinds of the leak. 
  • Quantity – Purchase a head gasket sealer that is enough for the leaks. If your car has a small engine, you should get a gasket sealer in a 16-ounce container. Having a small container that you can use for emergencies is also a good idea. 
  • Action Time – You can’t use your car for some time after pouring the sealant. As such, you should know long it takes for the sealer to settle down.  Head gasket sealers usually take around an hour to settle down. It depends on the radiator capacity of your car. 
  • Engine Compatibility – Gasoline and diesel engines might need different kinds of sealers. Check out the benefits of the head gasket sealer for your engine before buying one. 
  • Functionality – There are head gasket sealers that can perform other tasks aside from fixing leaks in the head gasket. Check out the product description to determine what else the sealer can do. 

Tips for Buying and Using Head Gasket Sealers

The best head gasket sealer seals minor to major leaks, helping you avoid or delay visits to the mechanic. It prevents coolant and oil from mixing. You only need to pour the head gasket sealer into the coolant reservoir or radiator, and it will circulate through the engine and fix existing leakages.

When your head gasket sealer works with antifreeze brands, you’re not required to drain the entire coolant system. You only have to keep the engine inactive for a short period of time. Other head gasket sealers require you to replace the coolant with water after draining the entire coolant system. You then need to pour the head gasket sealer to start run the engine. Drain the entire coolant system once more before putting the coolant back, and that’s it. 

Follow the instructions for the sealant you buy. Use the sealer in a well-ventilated area so that you don’t breathe in any chemical fumes. You should know when to use a head gasket sealer and when to replace the head gasket so that you can save money and time. A sealant is not enough to fix a worn-out gasket. 

It’s also important to confirm the sealer’s antifreeze compatibility. Check the manufacturer’s instructions to see if the sealer is compatible with your antifreeze brand.

Best Head Gasket Sealer FAQ 

Q: Is a head gasket sealer safe to use? 

A: Yes. A high quality head gasket sealer works effectively without damaging the engine. Most head gasket sealers are compatible with petrol and diesel engines and other materials like cast iron and plastic. 

Q: How long will the sealer last?  

A: It depends on the quality of the sealer and how severe the leaks are. If you’re dealing with minor leaks, a head gasket sealer will last for six months. However, a sealer is not a permanent solution to major leaks. If you’re dealing with major leaks, you may need to replace the head gasket.

Q: Is a head gasket sealer better than gasket replacement? 

A: It depends on the extent of the damage. Head gasket sealers can eliminate minor leaks permanently, but will only provide a temporary solution to major leaks. You need to replace the gasket eventually. 

Q: Will the head gasket sealer clog holes in other systems? 

A: Head gasket sealers can also clog leakages in the hydraulic, transmission, and power steering systems. If the sealer can’t handle larger holes, you should consider complete head gasket replacement. 

Q: How does a head gasket sealer work? 

A head gasket sealer prevents water and oil from breaching areas where they shouldn’t be by closing the joint between the engine block and cylinder head. It helps reduce fluid packages. Most head gasket sealers are available in spray, glue, or paste form. 

Our Top Pick

Our top pick is Bar’s Leak Head Gasket Repair because it’s easy to use, effective and affordable. It can also penetrate gaps and cracks and can stop leaks permanently once it hardens. If you don’t want to replace your gasket head too soon, you can use this product to fix it and save money.