Walnut Blasting – Restoring Performance and Efficiency

To comply with emission laws, most modern petrol and diesel engines have switched over to direct injection technology. As the name implies, Direct Injection involves injecting fuel directly into the combustion chamber instead of through the valves.

While this technology has many benefits, the biggest downside is that the fuel no longer contacts the intake valves. This contact would historically keep the valves free from deposits and functioning efficiently.

Lack of “Fuel Wash”

With the “fuel wash” stage missing, deposits form as oil mist from the crankcase ventilation and turbocharger blow-by mixes with hot air from the turbocharger and exhaust gas recirculation. When the oil mist reaches the hot valve, it sticks and burns, forming black carbon deposits.

Since this sludge is no longer washed away by fuel in the intake system, it accumulates, leaving a sticky mess that builds up over time.

As engine performance heavily relies on the amount of air available for combustion and efficient valves, a thick carbon layer reduces airflow, diminishing performance and eventually leading to issues like rough running, especially during a cold start.

Manufacturers At a Loss

To date, manufacturers have been unable to overcome this issue, leaving the after-service market and the consumer to deal with the problem.

Walnut blasting is recognised as the safest way to remove these deposits properly. The process involves:

  • Removing the intake manifolds to access the intake ports.
  • Using compressed air to blast biodegradable walnut shell chips onto the closed intake valves, chipping away the hard crust.
  • At the same time, an industrial vacuum cleaner extracts the debris.

Why Crushed Walnut Shells?

Crushed walnut shells are hard enough to remove the carbon yet soft enough to avoid damaging the metal. They’re biodegradable and a byproduct of the walnut industry, so walnut blasting is a great second use.


The results, as seen in the images, include:

  • Restored performance
  • Increased fuel efficiency
  • Improved emissions
  • Reduced wear
  • Smoother operation

A semi-regular treatment has become a necessary maintenance procedure for most modern cars. Depending on how the car is driven, this can vary between 50,000km and 100,000km.

At Eurotech Autohaus, we are equipped with all the tools to perform walnut blasting efficiently, cleanly, and thoroughly. Special adapters for most European cars ensure that debris ends up only in the required areas, leaving engines clean and functioning at their best.

Our trained professionals strictly follow manufacturers’ guidelines, and our sophisticated dealer-level diagnostic tools allow for the reset and recalibration of all involved electronics.

If your car has been sluggish or your fuel efficiency has been dropping, contact the team at (08) 94688128. We’re here to help.


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24 Radius Loop, Bayswater WA 6053

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