What Causes Engine Oil Leak Under the Car?

[ElijahDella]

The causes of engine oil leak under the car are: 1. Shock absorber oil leakage; 2. Brake master cylinder, wheel cylinder, or ABS pump oil leakage; 3. Clutch master cylinder or wheel cylinder oil leakage; 4. Half-shaft oil seal leakage; 5. Rear differential oil seal leakage; 6. Transmission oil pan leakage. Engine oil is the lubricant for the engine system, possessing certain properties such as oxidation resistance, wear resistance, and corrosion prevention. The method for changing engine oil is: 1. Lift the car, remove the protective plate, and place a container of about 10 liters under the oil drain plug; 2. Unscrew the oil drain plug, use an air gun to blow into the oil filler port for two minutes, then tighten the oil drain plug after draining and wipe it with a tissue to check for leaks; 3. Reinstall the protective plate, lower the car, and use a funnel to add engine oil through the filler port.

[McNolan]

Oil leakage under the car is quite common, and I've seen it many times. Usually, it's due to the aging and cracking of the oil pan gasket. Over time, the rubber becomes brittle, and oil slowly seeps out. Another common cause is the oil drain bolt not being tightened properly or having cracks during an oil change, or the oil filter not being securely installed—just a slight twist can reveal this. Another possibility is a damaged crankshaft oil seal, which is located near the bottom of the engine, making oil drips on the ground very noticeable. Other potential issues include problems with the valve cover gasket or loose connections at the oil pump interface in the cooling system. Oil leakage not only wastes oil but can also cause the engine to overheat or even fail completely. So, if you notice oil stains on the ground, it's best to visit a repair shop as soon as possible for inspection and repairs. Don't ignore it and let the problem escalate.

[MacKeira]

I found several main reasons for oil leakage under the car: First, the oil pan gasket may be aged or damaged, which is a common wear part, especially in older cars where leaks are more likely. Second, the drain plug might not have been tightened properly or could be damaged after maintenance, causing oil to slowly seep out. Third, the oil filter might not be installed correctly, and if the sealing ring is deformed, it will leak. Fourth, there could be issues with the front or rear crankshaft seals; poor sealing there will cause oil to flow to the bottom. Fifth, other components like the cylinder head gasket might have cracks leading to oil leaks. As a car owner, you should regularly check the engine bottom, simply feeling for oil traces with your hand. If unsure, take it to a professional shop to inspect with a lift. Untreated oil leaks can increase fuel consumption, pollute the environment, and may lead to more serious malfunctions, making driving unsafe.

[McDylan]

Oil leakage under the car is usually caused by several factors. The most common issue is aging of the oil pan gasket, where the rubber deteriorates over time, allowing oil to leak. Loose or defective drain plugs are also frequent causes, especially if not properly checked after an oil change. Failed oil filter seals are another high-frequency reason, often resulting from improper installation. Additionally, damaged crankshaft oil seals can cause oil to seep underneath the vehicle. Ignoring these leaks may lead to insufficient oil levels and accelerated engine wear. It's recommended to seek immediate repair upon noticing oil drips.