Yes, it is safe to add Sea Foam through a spark plug hole. Mechanics have used this method for decades to free stuck rings and clogged expander rings. How to do it: Remove the spark plugs and pour Sea Foam into each cylinder cavity through the plug hole. [Note that it’s easier to use Sea Foam Spray.] Let the engine sit and soak up to 3 days (if you have the time). Be sure to crank the engine once a day to loosen the rings. You can also add a little more Sea Foam to each cylinder each day as it sits. Adding Sea Foam to the crankcase oil helps, too!
We use necessary cookies to make our site work. We'd also like to set analytics cookies that help us make improvements by measuring how you use the site. These will be set only if you accept.
Based on your browser's "Do Not Track" or "Global Privacy Control" settings we have automatically rejected analytics cookies for you.
Necessary Cookies
Necessary cookies enable core functionality. The website cannot function properly without these cookies, and can only be disabled by changing your browser preferences.
Analytics Cookies
We use Google Analytics cookies to help us improve our website by collecting and reporting information on how you use it. The cookies collect information in a way that does not directly identify anyone.
Yes, it is safe to add Sea Foam through a spark plug hole. Mechanics have used this method for decades to free stuck rings and clogged expander rings. How to do it: Remove the spark plugs and pour Sea Foam into each cylinder cavity through the plug hole. [Note that it’s easier to use Sea Foam Spray.] Let the engine sit and soak up to 3 days (if you have the time). Be sure to crank the engine once a day to loosen the rings. You can also add a little more Sea Foam to each cylinder each day as it sits. Adding Sea Foam to the crankcase oil helps, too!