At the time I found this site, I had recently bought a truck that ran extremely well, but had sludge so bad to the point that the logo on the valve cover was formed in the sludge like a jello mold, and I didn't have the time to pull the engine out of the truck to thoroughly clean it, so I started digging around online to find products that could help me out with cleaning my engine internals and I came across this site in the process.