OEM Rear Head Plug 0009986590

The rear head plug, often referred to as a freeze plug or expansion plug, is a critical component located at the back of the engine's cylinder head. Its primary function is to seal the water jackets within the engine, preventing coolant from leaking out while allowing for proper thermal expansion and contraction of the engine materials. When the engine is operating, it generates significant heat, and the rear head plug helps maintain the integrity of the cooling system by ensuring that the coolant remains contained, thus optimizing the engine's performance and preventing overheating. In addition to its sealing function, the rear head plug also plays a role in the overall durability and longevity of the engine. If the engine coolant freezes, it can expand and potentially damage the engine components; the rear head plug acts as a safeguard against this risk. In cases where the plug becomes corroded or damaged, it may lead to coolant leaks, which can result in engine overheating and severe mechanical failures. Therefore, regular inspection and maintenance of the rear head plug are essential for vehicle owners to ensure the smooth operation of their engine and to avoid costly repairs.