Revitalize Your GDI Engine with Walnut Shell Blasting: The Latest Method for Clearing Carbon Buildup

Dear Mike, I recently heard someone mention Walnut shell blasting for cars and I’m not sure what it is. Can you explain what this process involves and why it might be necessary for car maintenance? Thanks for your help!
Sincerely, Violet.


Dear Violet,

I am so glad that you reached out to me about walnut shell blasting. In the professional auto repair world, it’s quite the buzzword lately as one of the best methods to clear out carbon buildup from older GDI engines. So, let me explain to you what the process involves and why it may be necessary.

When it comes to GDI engines, the combustion of fuel and air happens directly in the combustion chamber, which is different from traditional port fuel injected engines where the fuel is injected before the intake valve. This configuration may lead to the accumulation of carbon buildup on the engine’s intake valves and intakes manifold.

The engine oil, which circulates throughout the engine, can seep past valve seals and quickly become baked onto the valves, causing hesitation, poor drivability, or a check engine light appearance. That’s where the Walnut shell blasting comes in.

Walnut shell blasting uses finely crushed walnut shells that are blasted at high pressure to clean out the insides of the engine. The biodegradable abrasive helps to break down the buildup and residues on the intake valves and manifold, which allows for clean airflow and ultimately better performance.

Now, let me warn you; this is not a DIY or an hour-long procedure. It can be a pricey process as your mechanic will have to remove the intake manifold first. However, if you are a regular car owner and have a GDI engine, it might be worth it.

But there is good news. A Canadian company called Kleen-Flow has come up with products that can resolve these issues in most cases, and even help to prevent the buildup in the first place. Ask your service provider if they offer a full GDI cleaning service, which is a four-step chemical process designed to resolve the carbon buildup issues within these types of engines.

The bottom line is that if you are experiencing hard engine starts, rough cold idle, decreased acceleration, mechanical engine misfires, black exhaust clouds under hard acceleration, or a check engine light or flashing, then Carbon buildup could be the culprit. It is always wise to adhere to your manufacturer’s recommended service intervals and follow the advice of your trusted mechanic.

I hope this helps answer your question about walnut shell blasting and GDI engines. If you have any more questions or concerns, don’t hesitate to reach out.

Best regards,

Mike Urban