What size is the oil drain plug for a Corolla?
1 Answers
The oil drain plug for a Corolla is a 14mm bolt with a washer. The drain plug is the sealing bolt located on the engine oil pan. Typically, during vehicle maintenance, the drain plug needs to be removed to drain the old oil from the oil pan. The bolt is then reinserted, and new oil is poured into the engine through the filler port on top. Each time the oil is changed, the bolt threads and oil pan should be inspected. When replacing the washer, the tightening torque should be approximately 30 N·m. If the drain plug is not tightened properly, it can lead to engine oil leakage or even detachment, affecting engine performance. In severe cases, it can damage the engine and pose a significant safety risk to the driver. The drain plug itself rarely needs replacement unless the vehicle has a plastic oil pan, in which case the plug is made of a disposable material and must be replaced each time. However, the washer should ideally be replaced every time. Since oil is a fluid with strong permeability, the contact surface between the drain plug and oil pan cannot be perfectly smooth, leading to potential leaks. The washer deforms when tightened, and repeated use makes it difficult to fill the gaps, resulting in leakage. Therefore, the washer should be replaced with each oil change.