Do you see white or blue smoke coming from your exhaust? Or is your engine overheating or feeling sluggish, underpowered, and/or choppy? If so, you might be dealing with a blown head gasket.
A blown head gasket can cause all kinds of trouble, such as oil and coolant mixing, a loss of engine power, engine misfires, and more.
If you suspect head gasket trouble, before heading to a mechanic to take a hefty repair bill on the chin, there’s one other solution worth trying: a head gasket sealer.
In this article, we’re going to detail what a head gasket is and how it works. We’ll also cover what could cause it to blow and how a sealer might solve the problem.
Before that, though, we’ll dive straight into a list of the best head gasket sealers on the market. That way, those of you who already know you need one can get straight down to choosing the product you need for the problem at hand.
Quick Links to Our Top Recommendations for Top Head Gasket Sealers
- Steel Seal Blown Head Gasket Fix Repair Sealer
- Engine-friendly and can eliminate various symptoms, ranging from minor to major.
- ATP Re-Seal Stops Leaks, 8 Ounce Bottle
- Long-lasting, easy to use, and also acts as a conditioner for older rubber seals.
- K-Seal ST5501 Multi-Purpose One-Step Permanent Coolant Leak Repair
- Our top pick for novice DIY mechanics. This one is a cinch to use and can seal leaks in other areas, such as freeze plugs, water pump casing, engine blocks, and heater core
- Bar’s Leak HEAD SEAL Blown Head Gasket Repair
- The most effective option out there for vehicles that overheat fast.
- BlueDevil Head Gasket Sealer
- Long-lasting, user-friendly, and ideal for treating clogs.
- K&W Permanent Head Gasket & Block Repair with Nanotechnology
- Requires cleaning out your cooling system entirely. One for the mechanically savvy car owner only.
- Bar’s Leaks Head Gasket Fix
- An excellent preventative if you see the early signs of head gasket troubles.
- K&W FiberLock Head Gasket & Block Repair
- A solid option for treating more serious issues.
Note: Clicking the above links will take you to further information, current prices and customer reviews on Amazon.
Best Head Gasket Sealer – A Detailed Look at Our Top Recommendations
Below we’ve reviewed eight of the best head gasket sealers on the market to help you choose a product that’s suitable for your vehicle.
Steel Seal Blown Head Gasket Fix Repair Sealer – 8 Cylinder
Those of you with bigger engines can use this product. You’ll get two bottles, suitable for eight-cylinder engines.
If you’re nervous about applying a sealer, this is the product for you. Steel Seal has explicit instructions that anyone can follow. The instructions cover several scenarios. These include a bubbly radiator, water in your oil, or an expansion tank.
Steel Seal is appropriate for treating common blown head gasket symptoms. This encompasses watery oil, white exhaust smoke, external leaks, and engine overheating.
The label makes it clear that Steel Seal doesn’t work with all types of antifreeze. Still, there is a short list of recommended antifreeze and coolant, so you won’t have to spend time puzzling over which one to choose.
Blockages won’t be a concern with this sealer. This liquid works by bonding to cracks or breaches when exposed to high temperatures. There aren’t any particles or materials that can build up and cause issues.
Features and Specifications
- Two bottles.
- Compatible with gas and diesel engines.
- Made for 8-cylinder engines.
- 30-day return policy if not satisfied.
- Works within 30 minutes to one hour.
What We Like
- Clear instructions.
- Works rapidly.
- Treats standard and serious symptoms.
- Won’t damage or clog coolant system.
What We Don’t Like
- Not compatible with all types of antifreeze.
- Must have pre-existing knowledge of cars to use.
Summary
Do you have moderate to severely blown head gasket symptoms? This product might be ideal for you. If you’re unsure of what you’re doing, the clear instructions are a great bonus.
Click the link below to learn more.
Atp at-205 Re-Seal Stops Leaks, 8 Ounce Bottle
The ATP AT-205 sealer is perfect for vehicles suffering from multiple issues. It can work to rejuvenate rubber seals as well as gaskets. It’s also rated for use on power steering and transmission.
This sealer is versatile and can work with gasoline and diesel engines. Whether you have an automatic or manual transmission, ATP AT-205 is suitable.
ATP’s sealer is devoid of petroleum distillates that are capable of dissolving rubber. Needless to say, this isn’t something you want circulating in your engine. Weak or worn rubber sealants can contribute to leaks.
ATP AT-205 can also improve the flexibility of your rubber seals. As a plasticizer, it can help condition older, dried-out rubber. It can also clear sludge out of your engine to improve fluid circulation.
Novices, as well as experts, will appreciate the simplicity of this sealer. One bottle should be enough to treat a standard vehicle’s oil or coolant system (six quarts).
You won’t even have to change your oil before or after you use it. Flushing out your cooling system won’t be necessary either—just add it to your radiator. Of course, it’s preferable to do both of these things if your vehicle is due for them.
As long as the head gasket leak isn’t too severe, ATP’s sealer will close it up. A huge benefit of this sealer is that repeat applications are not necessary. Once a breach is sealed, it stays that way long-term.
Features and Specifications
- Bottle capacity: 8 ounces.
- One bottle treats six quarts of fluid.
- Compatible with diesel and gasoline engines.
- Seals mild to moderate leaks within five hours.
What We Like
- Works for more than just head gasket leaks.
- Compatible with all types of oils.
- No draining or flushing needed.
- Conditions seals.
- Clears sludge.
- Long-lasting.
What We Don’t Like
- Takes up to five hours of driving to seal leaks.
- Doesn’t work on badly cracked heads.
- Can dissolve internal paint, causing blockages.
Summary
If you want a sealer that’ll last a long time and act as a conditioner for older rubber seals, ATP-205 will work for you.
See this sealer for yourself here.
K-Seal St5501 Multi Purpose One Step Permanent Coolant Leak Repair
This product will appeal to inexperienced vehicle owners. As the name suggests, there’s only one main step involved in applying it.
Shake the bottle and pour the contents into your coolant reservoir or radiator and you’re good to go. You’ll only have to keep your engine idling for a maximum of three minutes to plug the leaks.
A standout feature of this sealer is compatibility. It can be mixed with any antifreeze safely. This saves you the chore of draining and flushing your coolant system.
Plus, it can seal leaks in other areas, such as freeze plugs, water pump casing, engine blocks, and heater cores.
This sealer uses a form of nanotechnology in the way of microfibers. These microfibers bond to the breach and mesh together. These microscopic fibers are too small to cause blockages elsewhere in your engine’s circulatory system.
Features and Specifications
- Bottle capacity: 8 ounces.
- Particles seal leaks up to 0.635 millimeters (0.025 inches) in size.
- One bottle treats up to 12 cylinders.
- Ceramic formula.
- Compatible with all types of antifreeze.
- Works within one to three minutes.
What We Like
- No draining or flushing needed.
- Simple to use.
- No waiting necessary—works within minutes.
- Keeps leaks patched long-term.
- Can also be applied to heater core and freeze casing.
What We Don’t Like
- Works for minor leaks only.
- Discolors certain brands of antifreeze.
Summary
If you have a small leak and are unsure where your leak is located, this sealer is ideal for you. It’s also great for vehicle owners with little to no practical knowledge.
Take a look at this sealer here.
Bar’s Leak Hg-1 Head Seal Blown Head Gasket Repair
If your vehicle’s engine overheats quickly, Bar’s Leak HG-1 might be the solution. This sealer is rated for use on vehicles that overheat fast.
The minimum requirement is that your vehicle has to be able to idle for 15 minutes without overheating.
You won’t have to flush out your coolant system before or after use either. It can be mixed with the contents of any cooling system, whether antifreeze or water.
The exception is if you have existing blockages or a dirty coolant system. In this case, you’ll have to flush it beforehand.
This sealer is made up of sodium silicate and carbon fiber particles. It also contains a patented solution to reduce overheating as it circulates.
This product can seal breaches in all sorts of materials. It can bond to plastics, iron, aluminum, copper, and cast iron. Even if you’re dealing with bubbles in the coolant reservoir, you can use Bar’s Leak HG-1.
You’ll be able to get your vehicle back on the road in less than an hour. The total treatment time is less than 45 minutes.
Features and Specifications
- Bottle capacity: 33.8 ounces.
- Compatible with gasoline and diesel engines.
- Mixes with all types of antifreeze and water-based coolant systems.
- Works within 45 minutes.
What We Like
- Can be effective on larger
- Keeps mild to moderate leaks plugged long-term.
- Works on vehicles that overheat rapidly.
- Suitable for bubbly radiators.
What We Don’t Like
- Can cause blockages in radiator or heater core if not flushed.
- Sealer is thick and takes time to pour.
- More severe breaches can reopen soon after application.
Summary
Those of you with little experience and vehicles in bad shape can make use of Bar’s Leak HG-1 sealer.
If you want to learn more about it, click the link:
Bluedevil Head Gasket Sealer – 32 Ounce
If clogs are a concern for you, BlueDevil sealer is a good choice. This sealer doesn’t contain any solid matter or particulates. It’s liquid only, the primary ingredient being sodium silicate.
A blown gasket can result in deterioration of the internal workings of your engine. The particulate-free solution guarantees no further wear and tear. You don’t want to add more problems on top of the ones you already have.
To use it, your coolant system has to be flushed out. You’ll also have to remove the thermostat. These steps are to ensure the sealer circulates as thoroughly as possible.
As you’d expect with sodium silicate, it can bond to nearly any material. Whether you have a leak or a crack in metal or rubber, this sealer can plug it up.
An attractive feature of this BlueDevil sealer is durability. As long as the damage isn’t severe, you can expect leaks to stay sealed for thousands of miles.
Features and Specifications
- Bottle capacity: 32 ounces.
- Works in 50 minutes.
- Free of particulates or solid matter.
- Compatible with gasoline and diesel engines.
- Treats four and six-cylinder engines.
What We Like
- Can’t cause blockages.
- Bonds to all materials.
- Treats common blown head gasket symptoms.
- User-friendly.
- Long-lasting.
What We Don’t Like
- Must flush coolant system and remove the thermostat.
- Not suitable for bigger engines.
Summary
If you want to use a sealer once and be done with it, BlueDevil will do the job.
This product is available for purchase at the following link:
K&W 401232 Permanent Head Gasket & Block Repair With Nanotechnology
If you’re mechanically savvy, you can make use of this head gasket sealer. Users who enjoy getting up close and personal with their cars will like this product.
You’ll get a chance to clean your cooling system out thoroughly. You actually have to drain and flush your coolant system more than once. In the process, you’ll be getting rid of any blockages or clogs you may have.
The directions detail every step you have to take from start to finish. Again, as long as you’re familiar with how your vehicle works you shouldn’t have any trouble.
This sealer uses nanotechnology. Crevices, cracks, and leaks are filled with flexible nanoparticles. This flexibility allows the sealer to hold even if plastics or metal contract and expand.
The nanoparticles are also resilient to the harsh environment inside your engine. They’re designed to withstand extreme temperatures and pressure.
You can use the K&W nanotechnology sealer on nearly any vehicle, gasoline or diesel. The same is true of engine size: it’s suitable for use on four to eight cylinders.
Beginners who want to give K&W sealer a try can do so. Bring your vehicle to your mechanic. The visit will still cost you less than repairing a blown head gasket.
Features and Specifications
- Bottle capacity: 32 ounces.
- Takes up to 15 hours to work.
- Treats four, six, and eight-cylinder engines.
- Compatible with gasoline and diesel engines.
What We Like
- Seals small breaches long-term.
- Cures early symptoms.
- Great for DIY mechanics.
- Seals some leaks permanently.
What We Don’t Like
- Not beginner-friendly.
- Takes time to work.
- Misuse can cause severe engine damage.
Summary
Would-be mechanics will appreciate the work involved with using this product. If you’re a novice, visit your local mechanic with a bottle.
If you want to know more about it, follow the link below:
Bar’s Leaks 1111 Head Gasket Fix – 24 Oz
This particular product is perfect for treating early signs of gasket trouble. It’s easy to use and can treat vehicles that overheat quickly (after a minimum of 15 minutes).
Anyone can use this sealer, regardless of skill level. You only have to pour it into your radiator and top it off with your coolant of choice. Since it can be mixed with any brand of antifreeze, compatibility is a non-issue.
After 20 minutes, your car will be ready to drive again. This sealer is effective at patching up minor leaks and breaches.
Bar’s Leaks 1111 sealer contains sodium silicate and nanoparticles. These compounds work together to bond to metals or plastics, filling leaks. The high temperature in your engine hardens the sealer.
This product is an excellent preventative. As long as the leaks haven’t escalated to moderate or severe, you’ll save yourself time and money. Repeat applications will likely be unnecessary with these sorts of leaks.
A single bottle will treat systems as large as sixteen quarts. This is more than enough for the majority of vehicles.
You won’t have to bother with flushing your coolant system if it’s clean. As with other Bar’s Leaks products, flushing is recommended for dirty systems.
Features and Specifications
- Bottle capacity: 24 ounces.
- Mixes with all types of antifreeze.
- Compatible with gasoline and diesel engines.
- Works in 20 minutes.
- One bottle treats six to sixteen-quart systems.
What We Like
- Successful at treating early issues.
- Can be used on vehicles that overheat quickly.
- Easy to use.
- Lasts for thousands of miles.
What We Don’t Like
- Can cause clogs in dirty coolant systems.
- Doesn’t work on larger breaches.
Summary
This sealer is ideal for users with vehicles that aren’t too far gone. If you’ve recently noticed indications of a blown head gasket, Bar’s Leaks 1111 is for you.
Follow the link below to see this product for yourself.
K&W 401224-6 Fiberlock Head Gasket & Block Repair – 32 Fl Oz
If you suspect your gasket trouble is serious, this sealer might work for you. Consider it as a last resort before giving up on your vehicle.
An added benefit is that it isn’t difficult to use. Uncap your radiator and pour it in. Then, leave your vehicle to idle with the heat on for 15 minutes.
As with other K&W sealers, it can be mixed with any coolant. There won’t be any need to flush your coolant system and buy a new brand of antifreeze.
This heavy-duty sealer includes nanotechnology in the formula. The sealer can reach and seal breaches throughout your coolant system and gasket.
The product forms a multi-layer web over the offending area. It also uses a conditioning agent to improve the transfer of heat in your engine.
Features and Specifications
- Bottle capacity: 32 ounces.
- Mixes with all types of antifreeze.
- Compatible with gasoline and diesel engines.
- Works in 15 minutes.
What We Like
- Seals large as well as small leaks.
- Keeps leaks plugged for a long time.
- Little effort involved to use it.
- Includes conditioning agent to regulate temperature.
What We Don’t Like
- Can cause radiator clogs.
- Applications may need to be repeated for severe leaks.
Summary
If you’re dealing with multiple symptoms, this product may be a saving grace.
Buy a bottle for yourself at the following link:
What Is a Head Gasket?
This component plays a principal role in your car’s internal combustion process. It prevents coolant fluid and oil from mixing together.
This crucial component is located between the cylinder heads and the engine block. To access it, a mechanic must remove the engine block.
To understand this component’s importance, let’s cover the basics of engine oils and coolants. This will help you to truly appreciate why it’s essential to prevent and/or fix a blown one.
The Importance of Engine Oil
Oil serves as a lubricant and cleaner for your engine.
While it’s running, an internal combustion engine is under a lot of pressure. The cylinders and pistons are in constant motion to generate energy. As you might imagine, constant friction is taking place.
Oil ensures that all the internal workings of your engine don’t wear down and also clears debris out of the engine. This is why you should prioritize staying on top of your oil changes.
The Importance of Coolant
This liquid circulates through your cylinder head (or heads) and engine block to prevent it overheating.
Coolant can withstand temperatures of either extreme. It enables your car’s engine to run during boiling summers and frigid winters alike. As with oil, your coolant fluid has to be changed every so often.
The Role of the Head Gasket
There are separate channels inside your engine block for coolant and oil. The head gasket seals these channels so the two can’t mix.
By providing a seal, it also maintains engine compression. This mechanism is what keeps your engine running smoothly.
Head gaskets are built to be durable. Typically, they are constructed from layers of steel. Other materials used can include aluminum, copper, and iron. Some include rubber for an extra tight seal.
The best materials for head gaskets are the ones that are heat-resilient.
Aluminum is susceptible to a phenomenon known as thermal expansion. When exposed to high temperatures, aluminum changes in shape and size. It expands, meaning that it’s likely to warp faster than other metals. A warped head gasket is an ineffective one. This is why we generally don’t recommend aluminum.
On their own, head gaskets aren’t costly to buy but repairing one runs high because they aren’t easy to access and replacing one is a time-consuming process.
Exhaust manifolds must be taken out, valves loosened, and more. Then, everything has to be replaced exactly as it was. The exact procedure will differ, depending on the make and model of the vehicle.
Attempting removal without being certain of what you’re doing is dangerous. You could injure yourself or cause serious damage to your engine.
What Is a Head Gasket Sealant? How Does it Work?
Head gasket sealants are chemical liquids that will seal minor to moderate leaks. These products give you the chance to delay or avoid an expensive visit to your mechanic.
Remember, the head gasket is crucial because it prevents oil and coolant from mixing. It also stops these two liquids traveling to parts of the engine where they shouldn’t.
With a sealer, you won’t have to get anywhere near the actual leaking head gasket. Instead, you pour the sealer into your radiator or coolant reservoir. The sealer will circulate through your engine and patch up existing leaks.
What Causes a Blown Head Gasket?
A blown head gasket just means one that isn’t working as it should. This term can refer to anything from one or two small leaks to a deformed, warped gasket.
The core cause of a blow out is excessive engine temperatures. In turn, this can be due to a range of issues. We’re going to list some of the most prevalent reasons why your engine could be overheating.
Staying on top of your vehicle’s maintenance is the best way to reduce the chances of problems. If you suspect a blown head gasket, consider the following possible culprits:
Low Coolant Levels
Take a look at your car’s coolant or antifreeze reservoir to see if it’s full. If your vehicle is an older model, you might not have a coolant reservoir.
Instead, you’ll have to open the radiator (when the engine is cool!) and look inside. If there isn’t enough coolant circulating in your engine, it’s going to get hot in there.
Old Coolant
Forgetting to change your coolant can lead to blown head gaskets. As with oil, coolant loses its ability to keep things cool as it ages.
Coolant comes in vibrant colors—red, blue, green, or yellow. These colors correspond to the composition of the antifreeze. If you see that your coolant is colorless or has debris in it, it’s time for a change. Be sure to flush all the old coolant out before adding fresh coolant.
Worn-Out Tubes
If the tubes that bring the coolant in and out of your radiator are worn out, the whole system can fail. If you see bulges or cracks, they’ll have to be replaced. The same goes if the tubes feel squishy to the touch.
Clogged Radiator
A clogged radiator won’t circulate coolant as it should. Blockages can be either internal or external. If you see that your radiator is filthy on the outside, hose it down. Air needs to be able to enter the radiator for it to work.
If this doesn’t work, the clog may be internal. It could be a build-up of rust or debris. In this case, it’s best to have a mechanic examine it.
Broken Fan
The fan in your vehicle is a vital piece of equipment. It operates alongside the internal cooling system to keep your engine from overheating.
If your fan is making a lot of noise, it could be worn down. Other signs of a malfunctioning fan include the engine heating up quickly when your car is idling.
Pushing an Overheated Engine
If you know your engine is overheating, don’t ignore it. Driving when the engine temperature is in the red zone can cause your head gasket to blow.
You could also irreparably damage other mechanisms inside your engine.
Poor-Quality or Old Head Gasket
If your head gasket is made of lesser-quality materials, it won’t be as durable. This is likely to occur in second-hand vehicles where the manufacturer’s original has already been replaced in a previous repair.
Older models can wear down and fail too. The ones in vintage vehicles tend to be less hardwearing than newer models.
How to Tell Your Head Gasket Is Blown
Every vehicle owner needs to be aware of the signs of a damaged head gasket. This isn’t the type of thing you can ignore, or pretend isn’t happening. If allowed to escalate, it can destroy your catalytic converter.
Luckily, a blown head gasket often presents clear symptoms. If you notice any of the following, it’s safe to say yours is blown.
Depleted Coolant or Oil
An early symptom of a blown head gasket is depleted coolant or oil. If you’re refilling your coolant or oil too often, there could be a leak.
Bubbly Coolant
A damaged head gasket can force gas into the coolant reservoir or radiator. This will present as visible bubbles, even when the engine is cool.
Deposits on Spark Plugs
Burning antifreeze can leave deposits on your spark plugs. This white build-up usually appears around the electrode and ground strap.
Overheating Engine
If your engine keeps overheating, a blown head gasket could be at fault. In addition to being the cause, an overheated engine can also be a symptom.
Choppy Engine
The head gasket also regulates compression inside your engine. A lack of compression will cut down on your engine’s overall power.
Your engine might sound choppy or whiny. Your vehicle won’t accelerate normally without optimal compression.
White Exhaust Smoke
White smoke coming from the exhaust can be a sign of a blown head gasket. If coolant leaks and hits the engine cylinders, it will be heated into steam.
The steam is then blown straight out of your exhaust pipe. Smoke from a blown head gasket has a distinctive sweet smell. You may also see water dripping from your exhaust along with this white smoke.
Blue Exhaust Smoke
Leaked oil from a blown head gasket can also cause unusual exhaust smoke. As with the coolant, the oil will hit the cylinders.
The oil interacting with the super-heated cylinders produces a blue-tinged smoke. Note that if the leak is large enough, the oil could catch fire.
Milky Oil or Oily Coolant
If the oil on your dipstick is milky-looking, it’s contaminated with coolant. The opposite applies to your coolant. An oily film on the surface of your antifreeze isn’t normal.
Does a Sealer Always Solve a Cracked Head Gasket?
No, it’s not always a permanent solution. If your head gasket is actually warped out of shape, sealant won’t be able to fix the problem.
A badly warped head gasket physically can’t form a seal. No amount of sealant will work on large breaches. Similarly, it won’t do much for numerous, large leaks.
How Long Does a Head Gasket Sealer Work?
There’s no conclusive answer to how long it will work. This is contingent on individual variables, such as the condition of your head gasket and the number of leaks.
The type of head gasket sealer you buy matters too. Certain chemicals can wear down, exposing the breach. Other variations are claimed to make a permanent fix.
The problem can get worse over time. If the symptoms return, the head gasket sealer has stopped working. Or, this could mean that new leaks elsewhere in the engine have formed.
If the damage is minimal, a sealer can work for a long time. Maintaining your vehicle correctly will help prolong the sealer’s longevity.
Compatibility – Gasoline or Diesel?
Diesel and gasoline engines are distinct from each other. They have separate ignition, outputs, and starter motors.
The head gasket sealer you choose has to be compatible with your engine. Always read the label before purchase.
Not all sealers work with gasoline engines and vice versa for diesel. Some brands are compatible with both and can be used on any vehicle. An incompatible sealer might not work, or can even cause damage.
You can also pick a head gasket sealer designed for specific engine sizes. For example, six cylinders, eight cylinders, etc.
Conclusion
Head gasket sealers can save you a considerable amount of expense. In many cases, these products can prolong the lifespan of a blown gasket for a good length of time, saving money in repair costs.
In our opinion, the best head gasket sealer is Steel Seal blown head gasket fix repair sealer. This product is engine-friendly and produced by a reputable manufacturer. It can eliminate symptoms, ranging from minor to major, and have your engine running smoothly again.
Do you have any questions, feedback, or comments for us? Please share your opinion in the comments, we’ll answer every single one!
