In the interest of saving money, I decided to try the former method, which required some intake valve cleaner (or carburetor cleaner), a set of hard plastic or soft metal picks, and a shop vacuum ...

Walnut shell blasting media is a cleaning method that basically sandblasts ... Once you're sure all the intake valves are closed, you can pour whatever chemical you're using into the intake ...

That ritual beats a Saturday of walnut‑blasting intake valves — this modern tune-up checklist shows how PCV crud can easily ...