The LIQUI MOLY 300 mL Hydraulic Lifter Additive (part 20004) is a single-can engine oil treatment aimed at valvetrain tick. The manufacturer says it targets noise from hydraulic lifters that have become contaminated or sticky, and that it cleans the oil passages and valve bores that feed them so the lifters can refill properly. It also says the treatment improves the lubricating properties of the oil it is mixed into. Compared with a generic solvent or a general-purpose oil stabilizer, the appeal is that LIQUI MOLY states the product is safe for turbochargers, catalytic converters, and GPF/DPF particulate filters, which matters if your engine has modern emissions hardware. Searches like "LM 20004 lifter tick additive," "quiet sticky hydraulic lifter oil treatment," and "GPF DPF safe lifter additive" point to this exact formula.
Fitment is application-based rather than tied to a specific vehicle. The manufacturer lists it for all 4-stroke gasoline and diesel engines, with or without turbocharging, and notes compatibility with most commercial motor oils and belt-in-oil systems. Owners on user forums report it helps when the cause is dirty or gummed-up lifters, but they also caution that ticking from genuine mechanical wear is not something an additive will cure, and that engines without hydraulic lifters will not benefit at all. Because the manufacturer says it is not suitable for motorcycles with wet clutches, check your application before adding it. Dosing is simple: one 300 mL can per 3 to 6 liters (3.2 to 6.4 US quarts) of oil, shaken well and added at any time.
The manufacturer describes it as a treatment for noise from contaminated or sticky hydraulic lifters, which it says cleans oil passages and helps restore proper lifter function. Owners on user forums note that ticking caused by real mechanical wear generally needs a mechanical repair rather than an additive.
Yes. The manufacturer states the additive is safe for use with catalytic converters and particulate filters (GPF/DPF).
The manufacturer says it is not suitable for motorcycles with wet clutches.
The manufacturer specifies one full 300 mL can for 3 to 6 liters (3.2 to 6.4 US quarts) of motor oil. The product is self-mixing, can be added at any time, and should be shaken well before use.
No. Owners on user forums point out that some engine families, such as certain VQ-series designs, use solid lifters, so an additive of this type cannot address their valvetrain noise.
This is a no-tools job. Shake the can well, then pour the full 300 mL into the engine through the oil filler cap, ideally with a funnel, after checking your oil level. The manufacturer says the product mixes itself into the oil and can be added at any time, so you can do it at a routine oil change or top-up. Run the engine normally afterward. Because the manufacturer's dosing is based on 3 to 6 liters of oil, do not add the can to an already full sump. Expect a gradual change rather than an instant fix, and if the tick persists after an oil change, the cause may be wear rather than deposits.
