Direct Injection Explained. Best I Have Seen..But That’s Just Me...

[Imp4]

Originally Posted by Dave1027
I don't see how that Gumout Regain can work. With an engine running, the stuff would simply blow right by the valves and the rushing air would dry off any small amount of solution that happens to hit the valve surface. Much more solution would hit the catalytic converter

If you do a little research you'll find plenty of documentation that shows the product works quite well.

 

[buster]

"What will help with these issues is Vavoline's Modern Engine Full Synthetic, which is specifically formulated with additives to reduce carbon buildup more than other oils. "It is hot there, so that oil has to be able to withstand oxidation, thermal breakdown, and degradation or that oil can form deposits over time," Warholic explained.
That's exactly what Valvoline Modern Engine does that other high-quality oils, even synthetics, don't. Valvoline Modern Engine is an oil that is specifically designed to address a problem and take measures to solve, while others remain seemingly fixated on the ineffective notion of cleaning by the use of special fuel. Warholic believes, "Modern Engine is only one designed for this.""