Should the Oil Filter Be Replaced When Changing Engine Oil?
4 Answers
When changing engine oil, it is necessary to replace the oil filter. If the filter is not replaced during an oil change, the new oil will be contaminated by the dirt retained in the filter paper as it passes through the filter, causing the new oil to become dirty quickly. Prolonged failure to replace the oil filter will significantly reduce its filtering efficiency, rendering it ineffective. Continuous driving under such conditions can accelerate wear on the internal components of the engine, and in severe cases, may lead to oil burning. The functions of engine oil include: 1. Reducing friction and high temperatures; 2. Minimizing gas leakage and preventing contamination from external pollutants; 3. Protecting components from contact with water, air, and harmful acidic gases; 4. Cushioning the pressure rise in the engine cylinder ports; 5. Flushing away dirt generated on the working surfaces of components.
Last time my neighbor Master Zhang reminded me, never skimp on the oil filter cost when changing engine oil. This thing is just like a water purifier's filter - after prolonged use, it's full of metal shavings and sludge. I once tried extending its service life, and the oil turned black as ink with the engine sounding muffled. Once the filter gets clogged, new oil gets contaminated immediately upon entry, making those expensive synthetic oils a total waste. Mechanic Xiao Wang said the pleated filter paper reaches saturation after just two months. Every removed filter during oil changes is rock hard. The worst scenario is filter paper rupture - metal debris entering the crankcase could cause cylinder scoring, with repair costs exceeding hundreds of filters.
Honestly, an oil filter only costs around 30-50 bucks, why save on that? I once repaired an engine where the owner skipped changing the filter three times in a row to save trouble. The result? Sludge clogged the filter into a solid lump, and the oil pressure light kept flashing. When we opened it up, the camshaft was covered in scratches. Now, during every maintenance, I make sure the mechanic installs a new filter. The rubber seal must be coated with oil as per instructions before installation, or it'll leak. A reminder for modified car enthusiasts: high-performance engines need even more frequent changes. After upgrading to a 2.0T, I change my oil filter twice as often as the factory recommendation.
Definitely need to replace it! The filter paper in the oil filter can only last for 5,000 kilometers. Once saturated with contaminants, it starts leaking dirty stuff back into the engine. Plus, the old filter contains half a liter of used oil—not replacing it is like dumping garbage into fresh oil. Mechanic Brother Li showed me a comparison: new filters can trap particles above 15 microns, finer than a human hair. Don’t believe those myths about non-replaceable filters—magnetic types can’t capture sludge either. OEM filters come with a check valve to prevent dry starts, but aftermarket ones might lack this feature.
