how well can you see the rear of the engine? You have a rear main seal that may be leaking, but you will need to clean the area and inspect. the flywheel will need to be removed to replace this seal, so you want to make sure this is where the leak is before dissassembly.
ok. Lets look ate the oil pressure switch, if it is leaking it will run down the block on the drivers side. here is a diagram for its location.
let me know if you need more help
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