Purpose and Specifications

LIQUI MOLY Diesel Purge (21957) is a powerful 500ml fuel system cleaner designed for all diesel engines, including those with turbochargers, catalytic converters, and DPF filters. It quickly removes deposits from injectors, nozzles, and combustion chambers to restore lost power, smooth out rough idling, and eliminate knocking or pinging.

Key practical benefits:

• Improves cold starts, acceleration, and engine response
• Reduces exhaust smoke, noise, and injector clatter
• Boosts fuel economy by ensuring optimum combustion
• Provides corrosion protection for the entire fuel system
• Prepares engines for emissions tests with cleaner exhaust

One 500ml can treats up to 70 liters of diesel fuel. Shelf life is 4 years when stored in a cool, dry place between 0°C and 30°C.

When to Use / Replace?

Use preventively every 20,000 km or annually during fuel filter changes to prevent buildup. For heavy deposits or poor performance like rough idling, smoke, or hesitation, apply as a shock treatment by running the engine directly on pure Diesel Purge through the fuel line or filter for 10-20 minutes at varying speeds. Repeat if needed for severe cases. Safe for regular maintenance without harming engine components.

FAQ

Is LIQUI MOLY Diesel Purge safe for modern diesel engines with DPF?
Yes, it's fully compatible with turbo diesels, catalytic converters, and particulate filters, helping reduce emissions without damage.

How often should I use it?
Every 20,000 km or once a year with fuel filter service for prevention; more often for cleaning existing issues.

Will it improve fuel economy right away?
Users notice better economy after cleaning, especially if deposits were causing inefficient combustion, often within the first tank.