Benefits:

  • Reduces oil leaks
  • Rejuvenates hardened or shrunken seals
  • Reduces exhaust (blue) smoke at start-up or on take-off
  • Reduces oil consumption and oil burning
  • Can save the expense of seal replacement
  • Reduces leaks in all types of gearboxes & differentials

Engine Stop Leak

Nulon Engine Stop Leak (ESL) is a result of the most advanced technology available in the control of engine oil leaks due to the failure of oil seals, particularly those of the elastomer type. Most engines use this material as the basis of their "rear main" and "timing cover" seals. These seals are difficult to replace and in many instances require engine removal, or at least considerable labour costs, to install replacements. ESL also effectively promotes better sealing of valve stem seals. ESL is safe to use in all petrol, diesel and LPG engines.

With time and heat seals become hard and lose elasticity. Special additives in ESL react with the seal material to rejuvenate the seal so that it regains elasticity and is once more able to perform its function of sealing.

Nulon Engine Stop Leak reduces annoying oil leaks in all petrol, diesel and LPG engines (cars). Use this product if your car/vehicle has any of the following symptoms: loses or leaks oil, blows blue smoke at start-up, on take-off after a period of idling at traffic lights, or when decelerating downhill.

To our knowledge, no other product available controls "oil leaks" as effectively as ESL. Nulon ESL can be used safely in all overhead cam and multi-valve engines. Unlike many stop-leak and stop-smoke products, Nulon ESL is not an oil thickener. It can be safely used in engines that require low-viscosity oils, e.g. SAE 5W-30.


  • Reduces oil leaks
  • Rejuvenates hardened or shrunken seals
  • Reduces exhaust (blue) smoke at start-up or on take-off
  • Reduces oil consumption and oil burning
  • Can save the expense of seal replacement
  • Reduces leaks in all types of gearboxes & differentials

Features: Nulon ESL is suitable for use in petrol, diesel and LP gas engines, and is safe for use in all mineral and synthetic oils.

Note: Nulon ESL can also be used to reduce oil leaks in gearboxes and differentials (add 60 ml per litre of oil). 


Add 1 bottle for every 5 litres of engine oil. Shake bottle and add contents to engine oil. Idle engine for at least 1 minute. Use with every oil change. To reduce gearbox and diff oil leaks, add 60 ml per litre of oil.

Note: It may take 14 days or 500 km to achieve maximum benefits. Excessively worn or damaged seals may not respond and will require replacement.


For advice, contact a Poisons Information Centre (Phone e.g. Australia 131 126; New Zealand 0800 764 766) or a doctor (at once).


Part numbers

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Engine Stop Leak
Part No.ESL

300 ml bottle
6 per carton

Barcode: 9311090000384

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