I've been cleaning the engine on my Jeep lately. The valve cover was completely covered in grease, but underneath there is still nice shiny black paint. Only problem was, there is a large barcode sticker on the end of it. I removed the sticker, but the glue didn't come off.
It seems to be water and WD-40 proof, and of course has been stuck on that hot valve cover for nearly 200,000 miles. Any thoughts how I can get it off without a belt sander?