What Causes Oil Filter Leakage?
2 Answers
The reasons for oil filter leakage are: a broken sealing gasket, not tightening it properly during installation, or overtightening which may cause the housing to crack. During engine operation, metal shavings, dust, carbon deposits oxidized at high temperatures, gummy deposits, water, and other contaminants continuously mix with the lubricating oil. The oil filter's function is to remove these mechanical impurities and gum, keeping the lubricating oil clean and extending its service life. An oil filter should have strong filtration capability, low flow resistance, and a long service life. Typically, the lubrication system is equipped with several filters of different filtration capacities: the oil strainer, coarse filter, and fine filter, which are connected in parallel or in series within the main oil passage.
I've been driving for over a decade and changed engine oil countless times myself. The main causes of oil filter leaks are either not tightening it properly during installation or aging/deformed sealing rings. In hot weather, oil expansion makes seepage more likely. With poor-quality filters, the rubber rings tend to dry and crack, causing leaks. Another common issue is worn filter base threads leading to insecure sealing. Some car owners buy cheap filters to save money but end up with bigger troubles. Oil leaks not only waste oil but also create messy stains on the ground - more dangerously, insufficient oil can cause engine overheating or even complete failure. I experienced this once, and since then I personally inspect the filter during every maintenance, choosing quality brands like Mann or Bosch. Regular maintenance prevents small issues from escalating - if you spot a leak, get it fixed promptly.
