Top 10 Best Engine Leak Sealers 2021

1. NO LEAK PREMIUM SEALERS 20401 Engine Oil Treatment,16 oz

  • Works in all gasoline and diesel engines including turbocharged, eco boost, hybrid and even racing engines, including 3, 4, 5, 6, 8 and 10 cylinder engines in all cars, trucks, vans and suv’s
  • In most cases the oil leak issue will be repaired with a single dosage. however, for best results and to prevent the problems from reoccurring, use with every other oil change, or once per year
  • This premium quality synthetic blend works with all types of motor/engine oil including regular petroleum, high mileage, synthetic blends and fully synthetic formulas
  • Can also be used in heavy-duty applications as well as tractors, boats, rv’s, motorcycles (including wet clutch), atv’s, lawn equipment
  • Use 1/2 bottle for smaller systems (3. 5 – 4. 4 quarts of oil), in larger systems use 1 bottle for every 6 quarts, in small engines use approximately 3oz to every quart of oil

2. Bar’s Leaks OS-1 Seal Engine Oil Burning/Leak Repair – 16.9 oz.

  • Stops oil leakages from the engine and prevents their emerging in the future
  • Reduces engine noise and oil consumption
  • Restores elasticity and stretch ability of rubber gaskets and seals
  • Eliminates the need for expensive repair
  • Compatible with motor oils of all types

3. XADO ATOMEX Stop Leak Engine Oil Additive Sealer (Bottle, 250 ml) – Repair Gaskets & Seals Treatment

  • Seals cracks and stops leaks: avoid expensive downtime, our coolant stop leak will permanently seal cracks and holes! quickly repair your head gasket, block, leaking radiator, freeze plug, heater core & water pump casing with no adverse impact on efficiency.
  • Scientifically tested: safe and effective, our heavy duty coolant stop leak repair seals leaks up to 1/32 of an inch! once cured, it withstands the high pressure of the combustion chamber, without failing or clogging the cooling system. us bestseller
  • Repairs in minutes: create a permanent weld within the entire coolant system, including on hard plastic radiators and aluminum heads and blocks in larger capacity engines, ag, rv etc. the only industrial coolant sealant university tested to meet astm d3147.
  • Pour and go: our cooling system sealer is easy to use just shake the bottle, add to your radiator/overflow and run the engine! unlike some competitive products, it mixes with all types of antifreeze, no draining, flushing or pulling the thermostat required.
  • Customer support: if our engine coolant leak doesn’t seal your head gasket, the system might be over-pressurized. check the technical specification section of this page for extra instructions for a successful repair. over 8 million bottles sold. save time/money

5. Bar’s Leaks – 1000 Engine Repair – 16 oz

  • Seals cracks and stops leaks: a diy alternative to costly repairs, our head gasket fix permanently seals cracks and holes! quickly repair your blocks, leaking radiator, freeze plug, heater core and water pump casing with no adverse impact on efficiency.
  • Scientifically tested: safe, effective, our head gasket and block repair seals leaks up to 1/32 of an inch! once cured, the repair withstands the high pressure of the combustion chamber, all without failing or clogging the cooling system. us bestseller
  • Repairs in minutes: permanently fix blown head gaskets, cracked heads and cracked/porous blocks including aluminum heads in old and new cars. the only head gasket and block sealant that is 3rd party tested to meet astm d3147. save time/money
  • Pour and go: our head gasket sealer is easy to use just shake, add to your radiator/overflow and run the engine! unlike some competitive products, it mixes with all types of antifreeze, absolutely no draining, flushing or pulling the thermostat required.
  • Customer support: if our head gasket repair leak doesn’t seal your intake gasket, the system might be over-pressurized. check the technical specification section of this page for extra instructions for a successful repair. over 8 million bottles sold.

7. BlueDevil Rear Main Sealer

  • Seals cracked cylinder heads and blocks
  • Dual action 2 part formula — liquid ceramic: liquid penetrates large and small leaks to form a seal actually harder than the original head gasket — reinforced fibers: fiber additives lock together with liquid to increase strength and promote a permanent seal
  • Included components: unit, instruction guide
  • Stops block leaks
  • Repairs blown head gaskets
  • Head gasket sealant is not compatible with antifreeze and must only be added to the cooling system after all antifreeze has been flushed and removed.

8. Bar’s Leaks 1100 Head Gasket Repair – 20 oz.

  • Renews worn seals with no risk of damage or eventual corrosion
  • Contains no harmful solvents
  • Compatible with petroleum, semi-synthetic and full synthetic motor oils
  • Reduces engine noise and oil consumption, while raising oil pressure

9. Lucas Oil 10278 Engine Oil Stop Leak, 1 Quart

  • Rejuivinates all rubber seals & gaskets in engines, transmissions, power steering, differentials and hydraulic systems
  • Does not contain petroleum distillates, will not over-swell or breakdown seals
  • Professional strength fast acting resealer, stops leaks fast
  • Compatible with conventional and synthetic oils, atf, gear oil, power steering fluids and hydraulic oil
  • 8oz bottle will treat a 6 quart capacity, adjust accordingly