Quick answer
Carbon cleaner (chemical) dissolves deposits progressively, while walnut blasting (mechanical) uses crushed shells to physically scour carbon off surfaces. Both remove deposits, but walnut blasting is more invasive.
Detailed answer
Chemical carbon cleaners and walnut blasting both aim to strip away stubborn residue, but they approach the job differently. A carbon cleaner relies on specific solvents or detergents that soak into the carbon buildup, gradually loosening it so it can be burned off or flushed out. Walnut blasting, by contrast, is a physical process: compressed air shoots finely ground walnut shells at carbon-caked surfaces to knock off debris. This mechanical method can be very effective, especially for heavily encrusted valves that chemical solvents struggle to penetrate. However, it usually requires partial engine disassembly for direct access, and if done improperly, abrasive particles could stray into sensitive areas. Chemical cleaners, on the other hand, are typically simpler to administer—often poured into the fuel system or sprayed into the intake—and can be performed more frequently without major teardown. They may, however, take longer to yield results, especially if buildup is severe. Choosing one over the other depends on factors like deposit severity, engine type, budget, and availability of skilled service technicians. Many drivers or shops start with chemical solutions and resort to walnut blasting if thick layers remain stubbornly intact. In both cases, the goal is the same: a clearer path for air and fuel, leading to a crisper, more efficient combustion.
