* Valve Cover Gasket: This is a very common source of oil leaks, especially when the engine is idling and oil pressure is lower. Oil can seep out and run down, sometimes making it appear to be coming from the oil pan. Inspect the valve cover gasket carefully for cracks or deterioration.
* Rear Main Seal: This seal is located where the crankshaft exits the engine block. Leaks from this seal are often worse when the engine is running, especially at idle, as the crankshaft's movement pushes oil past a weakened seal. This is a more involved repair.
* Oil Pressure Sending Unit/Switch: These are located on the engine block and can leak if the gasket or the unit itself is faulty. A small leak here can drip down and be mistaken for another source.
* Camshaft Seal(s): Similar to the rear main seal, these seals can leak, and the oil might run down to make it seem like it's from the pan.
* Crankshaft Position Sensor Seal: Though less common, a leak here can contribute to oil loss.
* Timing Cover Gasket: A leak from the timing cover could also run down to the pan area.
Troubleshooting Steps:
1. Thoroughly clean the engine: Use a degreaser and a pressure washer (carefully, avoiding electrical components) to remove all the old oil. This will allow you to pinpoint the exact source of the new leak. Let the engine run for a short while after cleaning to let fresh oil leak and show the source.
2. Visual Inspection: After cleaning, carefully examine all the potential leak points listed above. Look for oil stains, weeping, or dripping. A bright light and a mirror can help with hard-to-reach areas.
3. Start and Observe: Run the engine for a short period, paying close attention to where the oil is leaking from.
4. Check the PCV Valve: A faulty PCV valve can cause excessive crankcase pressure, forcing oil past seals and gaskets.
If you're not comfortable performing these checks yourself, take your Metro to a qualified mechanic. They'll have the experience and tools to diagnose and repair the leak accurately. The age of the car suggests several seals might be worn, so be prepared for multiple issues.
