Seafoam Valve Cleaning
From: http://volvospeed.com/volvo_repairs_h... Seafoam like Techron or any other valve cleaner or additive should only be used every 10-15k miles. Over the course of normal driving carbon deposits itself on the back of the valves and piston tops. Using a cleaner through the intake can help control these deposits, which can cause a loss in fuel economy and performance. Below you can see two pistons removed from an engine with 30,000 miles. The piston on the left is from a cylinder treated with Seafoam.
