Permanently seal cracks and coolant leaks with our top picks for head-gasket sealer.
By Noelle Talmon
5 minute read
Best Overall
Steel Seal Blown Head Gasket Fix Repair Sealer
Best Value
K-Seal ST3501 HD
Honorable Mention
BlueDevil Head Gasket Sealer
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Faulty head gaskets are no fun to deal with. This type of malfunction can cause a lot of issues, including engine misfires and oil leaks. While a bad head gaskets will eventually need to be replaced in most cases, gasket sealers just might buy you some time to get you by until you can afford to do so. There are numerous head gasket sealers available online and in stores, some intended to be used as mentioned, others to promote a seal during installation. This guide will help you decide which is best for your situation.
Summary List
- Best Overall: Steel Seal Blown Head Gasket Fix Repair Sealer
- Best Value: K-Seal ST3501 HD Multi Purpose One Step Permanent Coolant Leak Repair
- Honorable Mention: BlueDevil 38386 Head Gasket Sealer
Our Methodology
We selected this sturdy, extensive selection of head gasket sealers based on user experiences, effectiveness, price, and value. Some are on the higher-dollar side, some are very inexpensive. There are many sealers out there that have questionable effectiveness, but these three products’ reviews indicate that all hope is not lost. While a liquid sealer isn’t the most optimal fix for a head gasket, it could be enough to stave off a lofty repair bill for a good, long while. But of course, your mileage may vary. For more on how we select products for our reviews, check this out.
Best Head Gasket Sealers: Reviews & Recommendations
Best Overall: Steel Seal Blown Head Gasket Fix Repair Sealer
The Steel Seal gasket sealer comes in two bottles that are enough for people with bigger engines, such as eight-cylinder engines. The product comes with easy-to-follow instructions, though you need slight automotive knowledge to use it. This sealer is designed to solve different blown head gasket symptoms, which include white smoke, engine overheating, external leaks, and watery oil.
The biggest potential drawback is the need to flush the system prior to its use. That, stacked with the high cost, will push many to consider other options.
Best Value: K-Seal ST3501 HD Multi Purpose One Step Permanent Coolant Leak Repair
The K-Seal Coolant Leak Repair is a “shake, pour, and go” head gasket sealer that comes with an affordable price tag. This product’s standout feature is the fact that it’s compatible with any antifreeze product, which eliminates the need to flush out the coolant system before application. It’s a multipurpose product, and you can safely use the sealant to solve other leakage issues related to the heater core, engine block, water pump casing, and freeze plugs.
Unfortunately, there are some issues with this product. It is an affordable product that’s easy to use, but it really is suited for only small leaks. Reports of coolant discolorations may indicate the need to replace coolant once it’s done its job.
Honorable Mention: BlueDevil 38386 Head Gasket Sealer
The BlueDevil gasket sealer is an easy-to-use sealer that saves you money in repair bills for your car. It’s a professional-grade head gasket sealer that also solves leakage issues associated with the heater cores, freeze plugs, and other components associated with the coolant apart from the radiator core. As long as you follow the instructions provided, the sealer provides a permanent leakage repair solution.
It works so well, in fact, that it can even cause blockages if it’s not used correctly. It also works best when fresh coolant is added to the system, meaning you may want to flush the engine before and after using it to avoid issues.
Our Verdict on the Best Head Gasket Sealers
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.
How Much Are Head Gasket Sealers?
$20 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. If you are looking for a larger container that can fix a couple of leaks, then look into products in the $25-$50 price range. The containers typically have 32 ounces of fluid. That’s enough to handle six- and eight-cylinder engines.
FAQs
You’ve got questions. The Drive has answers.
Q. Are head gasket sealers safe for the engine?
A. Good-quality head gasket sealers are designed to work effectively without compromising the engine’s function. 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?
A. 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?
A. 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?
A. 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.
