• g+1


Engine Oil Supplement Assembly Lubricant | ACDelco

ACDelco E.O.S. (Engine Oil Supplement) Assembly Lubricant is specially formulated as an engine assembly lubricant that helps provide protection against run-in wear and piston scuffing. It also assists in protecting against run-in camshaft lobe and lifter scuffing resulting from insufficient lubrication. This product is not recommended for use as an additive to engine oil.


16 oz. Part No. 10-4021 88862587

Signs of Wear & Troubleshooting:

  • Indications that your vehicle components are in need of lubrication include nagging squeaks and rattles as well as vibration while driving.
  • Lubricants can also address squeaky and sticking latches and joints in places such as doors, hoods, tailgates and trunks.
  • Lubricants that create a wet film are most useful in exterior applications with high friction and metal-to-metal contact, whereas those that create a dry film are best for interior applications where they may come in contact with upholstery, clothing, etc.

Good Maintenance Practices:

  • When applying to crank and cam bearing, pour product over bearing and journals prior to installing crank and camshaft.
  • When applying to lifter assembly, dip base of valve lifters in ACDelco E.O.S. Assembly Lubricant, and pour product over camshaft lobes through lifter ports in engine block.
  • When applying to oil pump, fill oil pump cavity with product to facilitate priming.
  • When applying to piston and ring assembly, liberally coat with product before installing into engine.
  • When applying to engine bores, coat entire surface of engine bore prior to piston installation.
  • Keeping your vehicle well lubricated can help prevent major component failures and minimize the development of wear problems that require costly repairs. Vehicle components will deteriorate much faster if they are not properly lubricated to decrease friction and minimize damage, especially from metal-to-metal contact.
  • Proper lubrication provides solutions to increase driving comfort by reducing noise, vibration and harshness; performance, by helping to provide for durable, long-term functioning of automotive components; safety, by keeping hard-to-reach components working as designed; and reliability, by helping components to withstand extreme temperatures and harsh operating conditions.


Do synthetic lubricants provide significant advantages over petroleum-based versions?

  • Yes, synthetic lubricants are often better at very hot or very cold temperatures. Synthetic lubricants can also be more resistant to washout from exposure to water.


Do I need to clean off old lubricant and/or grease before applying this product?

  • No, it is not necessary to clean off old lubricant before applying this product because the new product will only add to the protection. Clean the area only if the old lubricant is contaminating other surfaces.


Can I use a combination of two types of lubricants and/or greases on the same component where they may come in contact with each other?

  • Yes, different lubricants can sometimes be combined, however, in order to obtain the most consistent results, it is best to use only one type of lubricant.


Is it easy to remove this product from my vehicle components, if necessary?

  • Yes, most lubricants can be removed with a cloth or rag. Do not use other solvents or cleaners because the new application of lubricant may be negatively impacted bythe cleaner solvents.



Search Parts Cataloge
Locate Service Center
Locate Parts Store