Gio's Walnut blasting blog VW engine

What is Intake Walnut Blasting?

Updated: Dec 23, 2020


Before and after intake valve blasting
Before and after intake valve blasting


Why carbon builds up in intake valves?


Regardless of the type of fuel management system used, carbon buildup is an unfortunate consequence that occurs over time. In older vehicles, fuel typically flows through intake ports and valves, where carbon buildup occurs. With direct-injection technology in modern cars, fuel is sent into each cylinder, bypassing the intake, but carbon is still likely to cake cylinder walls.


What happens when carbon builds up?


Carbon deposits accumulating over time can build up into a thick layer and cause serious issues such as:


Restricts airflow to the engine that results in noticeable loss in performance.

Engine misfires.

Check engine light getting switched on.

Poor fuel economy.

Rough running or sluggish performance.

Extended cranking/ start times.



Which cars require intake walnut blasting?


Direct injected cars have a significant drawback as compared to port injected ones. Carbon deposits have to be removed at regular intervals. Vehicles with a gasoline direct injection engine such as an Audi, BMW, Cadillac, Mercedes-Benz, Mini Cooper, Volkswagen, etc. require intake cleaning via this method. It allows manufacturers to increase fuel mileage without compromising the vehicle’s power or efficiency. Using crushed walnut shells propelled by compressed air, the carbon buildup is gradually chipped away at. Since walnut shells are softer than the metal of the intake valves, they don’t cause any damage, while being tough enough to remove deposits.



When should walnut blasting be done?


Ideally it depends on the way in which you drive your car. If you are letting your car fully come up to temperature and then revving out the engine through it is entire RPM range, the buildup is likely to be lesser than someone who has a 3 to 5 minute commute to work. It is recommended that intake blasting should be done between 60000 and 80000 km. However, if your car is brand new, you can get it done somewhere between 40,000-50,000 .


What are the benefits of intake walnut blasting?

Better vehicle performance

Soot escalation is always a problem, as it hampers key components in the car. Whether the carbon buildup is in the valves, ports or combustion chamber, it eventually impacts performance. Get rid of the carbon and enjoy the boost in acceleration.


No more engine knock

Engine knock can cause damage to the cylinder wall and piston, but removing carbon ensures your engine is running smoothly once again.



Great fuel efficiency

Accumulation of carbon over time affects performance, which is directly related to fuel economy. Once you remove buildups, the fuel economy improves a great deal.





Reduce harmful emissions

When the engine runs poorly, it consumes more fuel, which in turn leads to more pollution as the vehicle expels harmful emissions through the exhaust system. Carbon footprint and emissions are reduced by removing buildups in the intake valves.



What is the price and time frame of walnut blasting?


Walnut blasting will cost you in the range

of $500 and $1200 depending upon the make & model of the car, its condition, how many miles traveled, and so on. The process usually takes around 3 to 4 hours.

Walnut blasters are similar to sandblasters but gentle enough to maintain


integrity of the engine parts. Don’t try to strip the engine and clean the intake valves manually – it is tedious and time-consuming, and might end up damaging components. Clean up the carbon buildups via walnut blasting by a professional.


Thanks for reading our article. Feel free to ask us any question or comment.


Zach C.


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