👉 Stuck fluid, also known as stuck oil or emulsion, occurs when oil and water do not fully separate due to the presence of surfactants or other additives that cause them to form an emulsion. This results in a viscous, often black or dark brown substance that is difficult to drain from surfaces like engine blocks, fuel tanks, or hydraulic systems. The trapped oil and water prevent proper lubrication and cooling, leading to potential engine damage, reduced performance, and costly repairs.
