Mercury - Oil Cooler MerCruiser Sterndrive & Inboard Series Black Anodized Housing 8M0107033. Overview. If you spend enough time on the water, you learn to appreciate the parts you never actually see working. The oil cooler is one of those unsung pieces of gear-quiet, tucked away, but absolutely essential. When you throttle up, chase a rising tide, or push through a long run across open water, you're trusting that your engine temperature stays steady and your oil stays healthy. That's exactly wh