- Honey or yellow oil is brand new and smells sweet. Diesel engines built before 2000 will blacken the oil in about five engine hours. Newer diesel engines and most gasoline engines usually will not dirty the oil for a longer period of engine hours.
- Coffee or black oil has removed carbon from the combustion chamber of the pistons and smells of burnt, carbon odor and taste (Yes, I taste my oil although you may wish to refrain). So, monitor your oil change cycle and be sure to change the filter too.
- Chocolate milk means raw water has leaked into the lubricating oil and the engine should not be operated. Water can enter the oil system through a raw water leak in an oil cooler heat exchanger or worse, a cracked head or gasket.
- Strawberry milkshake color may be raw water leaking into the transmission cooler heat exchanger and mixing with ATF, Automatic Transmission Fluid.
Learn more about DIY owner maintenance in our next Introduction to Boat Systems course. Click here for information about our classes or call 772-205-1859 to find out about our next class and learn how you can participate.