Generic Hydraulic Lifter Additive — 2 Pack (2×300 ml) for Gasoline & Diesel, reduces lifter noise

LIQUII MOLY Hydraulic Lifter Additive is a concentrated oil-treatment that reduces hydraulic lifter noise while cleaning valve bores and restoring smoother lifter operation.

This two-bottle pack contains 2 × 300 ml doses of a specialist formula designed to be mixed into engine oil for both gasoline and diesel engines, including turbocharged units. The additive targets the deposits and varnish that cause noisy or sticking hydraulic lifters, and it works with all common engine oils. It has been tested for compatibility with catalytic converters and can be used safely in vehicles fitted with turbos.

How will this additive affect noisy hydraulic lifters?

The product helps dampen the tapping and ticking noises that come from worn or gummed-up hydraulic lifters by improving lubrication and loosening deposits. It does not replace mechanical repair but can restore quieter operation and reduce the urgency of immediate disassembly in some cases.

• Targets varnish and sludge in lifter holes and valve bores
• Enhances oil film to reduce metal-to-metal noise
• Can bring noticeable noise reduction after one treatment

How do I use the 300 ml bottle and how much oil does it cover?

Each 300 ml bottle treats engines with up to 6 liters (6.34 quarts) of engine oil. Add the bottle to warm engine oil with the engine off, then run the engine for a short period to circulate the additive. Follow standard safety and disposal practices for used oils.

• One 300 ml dose treats up to 6 liters of engine oil
• Add to oil while warm, then let engine circulate to distribute
• Two bottles give enough for two treatments or larger sumps

Is it safe for my engine, catalytic converter and turbocharger?

Formulated to mix with all commercially available engine oils, this additive has been tested for catalytic converter compatibility and is suitable for turbocharged engines. It improves lubrication without requiring oil-type changes, but always follow your vehicle manufacturer's maintenance guidelines.

• Compatible with gasoline and diesel engines
• Tested for catalytic converter safety
• Suitable for turbocharged and naturally aspirated engines

What performance or handling details should I expect?

The formula both cleans deposits and enhances the lubricating properties of the oil to help hydraulic lifters operate more smoothly. It has a flash point around 60°C; store and handle accordingly. Results depend on the level of wear and deposits—severe mechanical damage may still need professional repair.

• Improves oil lubricity and cleans valve bores
• Flash point approximately 60°C — handle with care
• Sold as a 2-pack for multiple applications

Who is this for: This LIQUII MOLY 20004 Hydraulic Lifter Additive 2-pack is aimed at car owners and DIY mechanics who want to quiet noisy hydraulic tappets, refresh engines with deposit buildup, or perform preventative maintenance. It’s suitable for owners of petrol and diesel cars—especially those with turbochargers or catalytic converters—who prefer a simple oil-treatment solution before deciding on more invasive repairs. Use it when topping up or changing engine oil to help maintain smoother lifter action and cleaner valve bores.