Do you like having some walnuts now and then—a solid, healthy snack? Your car may feel the same way.
Up until a few years ago, some manufacturers were making fuel-injected engines that, over time, have a tendency to get gunk buildup on valves, reducing engine performance in several ways: loss of power, rough idling, reduced fuel economy, and the “check engine” light coming on.
For particular models, one solution is walnut blasting–high-pressure air filled with finely crushed walnut shells to clear out the gunk and help the car run better.
Up until 2016, BMW recommended service interval walnut-blasting to clean out the intake valves on certain models, and other older vehicles with a similar fuel-injection system of that type include Audi, Volkswagen, and MINI.
There is no long-term solution for the problem, which comes from trace amounts of engine oil getting through seals and baking onto the intake valves, so regular cleaning is necessary to keep an engine running optimally.
If your car isn’t performing the way it should, it could be a matter of buildup on your intake valves. Ask your licensed automotive repair shop about a tune-up and possibly blasting that gunk away with crushed walnut shells. Repair shops may also offer a chemical intake cleaning, which is typically less labor-intensive and cheaper.
The Department of Consumer Affairs’ Bureau of Automotive Repair licenses automotive technicians who can answer your questions and provide quality service. You can verify that a shop is in good standing by visiting https://search.dca.ca.gov.