Best Head Gasket Sealers

BlueDevil Head Gasket Sealer will cost you, let's get that out of the way first. But the product will only cost you at the beginning and will likely save you more money than you'd expect in the long run.

First things first, the solution is basically harmless, with the formula free from solid and particulate matter that might harm the vehicle's engine. Normally, harmless means pretty much useless but that's very much divorced from reality here. On the contrary, this product is more effective than any sealer we've looked at. Sure, with its help, you'll be able to repair and seal leaks in blown head gaskets. In addition to that though, the solution is also capable of sealing warped and cracked heads, heater cores, and freeze plugs.

It is able to work with steel, aluminum, cast iron, plastic, and elastomer, further expanding the product's application range. All you have to do is slowly pour the liquid into the radiator and let the automotive idle with the radiator cap on for ~50 minutes.

From where we're standing, the product's flaws are limited to the fact that the agent does not last once you open the bottle, so we would not recommend investing in this product when all you have to do is seal one small crack. Other than that, there's no reason not to give this blown head gasket sealer a go.

Bar's Leak HG-1 believes that modesty is unnecessary. This product not only does basically everything but it is able to do that better than most targeted solutions.

Using this agent, you'll face very few challenges repairing blown head gaskets and intake gasket leaks. The product will allow you to seal warped and cracked heads and blocks. Preventing coolant loss, the agent will be eliminating overheating. You'll even be able to fix the issue with bubbles entering the cooling system. All that being said, the agent is pretty thick, thick enough to sometimes clog cooling systems, so we would recommend taking the dimensions into account before pouring the product.

When treating issues with head gaskets though, you won't have to do much more than pour the solution into the radiator and allow the vehicle to idle with the radiator cap on for 15 minutes tops. Plus, besides cast iron, aluminum, steel, plastic, and elastomer that most sealers are suitable with, this agent also works with copper elements and silicone parts.

Before wrapping this one, the bottle packs almost 34 fluid ounces, so you'll even be able to treat vehicles with V8 and V12 engines. To sum this up, there's practically no occasion that Bar's Leak HG-1 cannot rise to.

BlueDevil Pour-N-Go does not require ample experience in the engine field. In fact, as far as we're concerned, this is one of the easiest and more straightforward sealers we've come across.

As the "Pour-N-Go" part of the name would imply, the only action required from you is pouring the solution into the vehicle's radiator. Then, make sure the said vehicle is idling with the radiator cap on for about 50 minutes. Sure, 50 minutes is more than you'd expect considering that "Pour-N-Go" part that we've addressed above but that's where the product's shortcomings basically conclude.

Using this product, you'll be able to seal blown, cracked, and leaking head gaskets knowing that the seal will be close to permanent. The product is compatible with 4-cylinder and V6 engines, so most cars will apply here. Also, the agent works with most materials, including elastomer, plastic, aluminum, cast iron, and steel. To conclude its compatibility range, the product can be used with water, antifreeze, and most coolants. The formula is not thick at all, so you won't be clogging the cooling systems.

Again, you don't have to be an experienced, big-time mechanic to use this product and fix most issues with head gaskets.

K&W 401224-6 FiberLock is less about guesswork and more about precision and targeted treatment. With this product, you not only will be fixing head gaskets, cylinder heads, engine blocks, and cooling systems, you'll also be making sure you're not facing these problems down the road anymore.

Employing military-strength fibers, the solution puts multiple layers over the treated areas with web-like weaves enclosing the cracks. With nanobots, the product ensures that even the smallest cracks and crevices remain sealed. Meanwhile, the Cool-X Conditioner tech will be lowering operating temperature as the solution is circulating through the cooling system, preventing overheating. This part will also allow the car to take less time to start during freezing temperatures. The agent's compatible with most antifreeze types, so you won't have to purchase anything specific.

We were thoroughly impressed with the product except for the part where you have to shake the bottle for 30-60 seconds before usage, which is pretty tedious but not something that breaks the product. Considering its potency, it is hard to imagine anything breaking this product and hard to imagine car owners that won't be able to benefit from this head gasket sealer somewhere down the proverbial road.

K-Seal ST3501 keeps things simple and the price more than reasonable. The product presents that permanent fix that blown head gaskets, porous engine blocks, and cracked heads/blocks need to stop harming the engine. Its formula is compatible with most (likely even all) water-cooled engines, meaning you won't have to drain and flux the cooling system and you won't have to buy specific coolants or antifreeze products different from what you've been using before. Just shake the bottle, pour the solution into the radiator, and allow the car to idle for 20-30 minutes, removing the radiator cap beforehand.

The 16-fluid-ounce bottle will be enough to treat even SUVs and small trucks' cracked heads and blown head gaskets. With larger engines, all you have to do is double the dosage and add another bottle.

The product works with cast iron, steel, aluminum, plastic, and elastomer, not unlike the sealers we've reviewed above. It won't be able to seal large cracks though, something that the previous product is capable of.

Even taking that into account though, this is a solid head gasket sealer that should be able to allow drivers with blown head gaskets to fix the issue with the engine without paying professional mechanics a king's ransom.