Best Engine Oil Stop Leak Additive of 2026

Last updated on 05/04/2026
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1
9.8
Exceptional
ATP AT-205 Re-Seal Stops Leaks Fast In Engines & Transmissions - English & French 236ml
ATP Automotive

ATP AT-205 Re-Seal Stops Leaks Fast In Engines & Transmissions - English & French 236ml

Why we love it
  • Stops leaks quickly and effectively.
  • Rejuvenates rubber seals effortlessly.
  • Compatible with all oils available.
Main Highlights
  • Professional strength fast acting resealer, stops leaks fast.
  • Rejuvenates all rubber seals & gaskets in engines, transmissions, power steering, differentials and hydraulic systems.
  • Compatible with conventional and synthetic oils, ATF, gear oil, power steering fluids and hydraulic oil.
  • Does not contain petroleum distillates, will not over-swell or breakdown seals.
  • 236ml bottle will treat up to a 6 quart engine capacity (5.7 Litres.) Adjust accordingly.
9.8
Exceptional
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Best Value
2
9.7
Exceptional
Lucas Oil 10279 Gallon Engine Stop Leak, 3.785 Litre
Lucas Oil

Lucas Oil 10279 Gallon Engine Stop Leak, 3.785 Litre

Why we love it
  • Extends oil life significantly.
  • Safe for any engine.
  • Reduces engine noise effectively.
Main Highlights
  • Extends the life of engine oil by at least 50%
  • Contains nothing that could be harmful to an engine
  • Less engine noise
9.7
Exceptional
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3
9.7
Exceptional
LIQUI MOLY Pro-Line Oil Loss Stop | 1 L | Oil additive | SKU: 5182
Liqui Moly

LIQUI MOLY Pro-Line Oil Loss Stop | 1 L | Oil additive | SKU: 5182

Why we love it
  • Reduces oil consumption significantly.
  • Regenerates rubber and plastic seals.
  • Suitable for all engines.
Main Highlights
  • Suitable for all petrol and diesel engines with or without a diesel particulate filter (DPF).
  • Can be mixed with all commercial engine oils.
  • 1 L, enough for around 15 L of engine oil Sealing action after 600 - 800 km
  • For professionals only!
  • Oil Loss Stop regenerates rubber and plastic engine seals (e.g., shaft seals and valve stem seals). Reduces oil consumption through piston rings (due to its uniform viscosity) and through valve guides (by regenerating the seals).
  • Suitable for all gasoline and diesel engines.
  • Contents of the can (1 liter) are sufficient for up to 15 liters of motor oil. The product can be added at any time. After adding, run the engine until warm or drive the vehicle.
9.7
Exceptional
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4
9.6
Superb
LIQUI MOLY Pro-Line Gear Oil Leak Stop | 500 ml | Oil additive | SKU: 5199
Liqui Moly

LIQUI MOLY Pro-Line Gear Oil Leak Stop | 500 ml | Oil additive | SKU: 5199

Why we love it
  • Regenerates hardened seals.
  • Prevents polluting oil stains.
  • Ensures lasting effect.
Main Highlights
  • For all manual gearboxes, drive shafts and differentials.
  • Do not use in fully-automatic transmissions and transmissions with clutches that run in oil baths.
  • 500 ml, enough for around 10 L gear oil.
  • For professionals only!
  • Stops oil losses in dripping transmissions. Regenerates hardened rubber and plastic seals. No more polluting oil stains.
  • For all manual, auxiliary and differential transmissions.
  • Contents of can (500 ml) sufficient to treat up to 10 liters of gear oil. The product can be added at any time. Sealing first takes place after about 600 to 800 km of driving.
  • To guarantee a lasting effect, we recommend using Pro-Line Gear Oil Leak Stop at every oil change.
  • Note: Not suitable for use in fully automatic transmissions or in transmissions with a wet clutch!
9.6
Superb
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5
9.4
Superb
3x Lucas Engine Oil Stop Leak 946ml | Stops Leaks & Oil Burning|Engine Treatment
Generic

3x Lucas Engine Oil Stop Leak 946ml | Stops Leaks & Oil Burning|Engine Treatment

Why we love it
  • Stops oil leaks instantly.
  • Reduces oil burning effectively.
  • Extends engine life significantly.
Main Highlights
  • Instantly Reduces Oil Leaks – Specially formulated to condition and swell seals, helping stop common engine oil leaks fast.
  • Cuts Down Oil Burning & Smoke – Restores worn engine components to reduce exhaust smoke and oil consumption in older or high-mileage vehicles.
  • Protects & Extends Engine Life – Adds a protective lubricating layer to minimize friction and wear, improving overall engine performance.
  • Safe for All Petrol & Diesel Engines – Compatible with all conventional, synthetic, and semi-synthetic oils; works perfectly in cars, vans, trucks, and SUVs.
  • Cost-Effective Repair Alternative – Helps prevent expensive mechanical repairs by rejuvenating seals and internal components for long-lasting protection.
9.4
Superb
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6
9.3
Superb
2x Lucas Engine Oil Stop Leak 946ml | Stops Leaks & Oil Burning|Engine Treatment
Generic

2x Lucas Engine Oil Stop Leak 946ml | Stops Leaks & Oil Burning|Engine Treatment

Why we love it
  • Instantly stops engine oil leaks.
  • Reduces smoke and oil consumption.
  • Extends engine life and performance.
Main Highlights
  • Instantly Reduces Oil Leaks – Specially formulated to condition and swell seals, helping stop common engine oil leaks fast.
  • Cuts Down Oil Burning & Smoke – Restores worn engine components to reduce exhaust smoke and oil consumption in older or high-mileage vehicles.
  • Protects & Extends Engine Life – Adds a protective lubricating layer to minimize friction and wear, improving overall engine performance.
  • Safe for All Petrol & Diesel Engines – Compatible with all conventional, synthetic, and semi-synthetic oils; works perfectly in cars, vans, trucks, and SUVs.
  • Cost-Effective Repair Alternative – Helps prevent expensive mechanical repairs by rejuvenating seals and internal components for long-lasting protection.
9.3
Superb
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7
9.1
Superb
2 x Lucas Engine Oil Stop Leak 946ml
Lucas Oil

2 x Lucas Engine Oil Stop Leak 946ml

Why we love it
  • Compatible across different motor oils.
  • Safely renews worn seals.
  • Reduces noise, improves performance.
Main Highlights
  • Compatible with petroleum, semi-synthetic and full synthetic motor oils
  • Renews worn seals with no risk of damage or eventual corrosion
  • Reduces engine noise and oil consumption, while raising oil pressure
  • Contains no harmful solvents
  • Lucas Engine Oil Stop Leak is an all new formulation of Lucas additives and very specific base stocks designed to stop seal leaks in engines!
9.1
Superb
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8
9.0
Superb
JLM Engine Oil Stop Leak | Additive for Motor Seal Leaks & Lubrication, 250ml (J06055)
JLM

JLM Engine Oil Stop Leak | Additive for Motor Seal Leaks & Lubrication, 250ml (J06055)

Why we love it
  • Stops harmful oil leaks.
  • Reduces harmful emissions effectively.
  • Enhances overall oil efficiency.
Main Highlights
  • STOP & SEAL MOTOR OIL LEAKS: JLM’s Engine Oil Stop Leak contains the latest in seal-swell additive technology that helps restore the pliability of oil seals & supports the lubrication system of an older combustion engine
  • REDUCES EMISSIONS: This additive works to restore oil seals & reduce oil burning in the combustion chamber, cutting blue exhaust smoke
  • REDUCE OIL CONSUMPTION: The formula boosts oil viscosity to reduce the quantity of lubricant burnt within the compression chambers which can improve overall oil efficiency
  • SUITABLE FOR A VARIETY OF CARS: Designed for all petrol, diesel, hybrid, LPG & NGV cars, but most beneficial in older, higher mileage engines; not suitable for oil seals that have collapsed or suffered from mechanical damage
  • EASY TO USE: We recommend dosing around the time of your car service; add the whole bottle (250ml) to the sump before the old oil is drained & fresh lubricant is added; treats 3 to 6 litres of motor oil & can be mixed with all engine oils
9.0
Superb
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9
8.9
Excellent
2 x Engine Oil Stop Leak Sealer Treatment Additive For Petrol & Diesel Engines 300 ml, Renews Seals and Gaskets Repairs and protects, Specially formulated and Prevents Minor Oil Leaks
AXpower Inspirational Technology Empowering People

2 x Engine Oil Stop Leak Sealer Treatment Additive For Petrol & Diesel Engines 300 ml, Renews Seals and Gaskets Repairs and protects, Specially formulated and Prevents Minor Oil Leaks

Why we love it
  • Repairs and protects engine components.
  • Eliminates costly mechanical repairs.
  • Compatible with all motor oils.
Main Highlights
  • Renews Seals and Gaskets, Repairs and protects & Specially formulated
  • Helps repair engine heat damage
  • Eliminates the need for oil leak mechanical work.
  • Increases existing engine oil protection
  • Suitable for regular/synthetic motor oils
  • Will not harm oxygen sensors or catalytic convertors
8.9
Excellent
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10
8.8
Excellent
Lucas Oil 10278 Engine Stop Leak, 946 ml
Lucas Oil

Lucas Oil 10278 Engine Stop Leak, 946 ml

Why we love it
  • Extends oil life substantially.
  • Engine-safe and reliable.
  • Reduces engine noise.
Main Highlights
  • Extends the life of engine oil by at least 50%
  • Contains nothing that could be harmful to an engine
  • Less engine noise
8.8
Excellent
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