2001 BMW 325i Repair Question
There's two tests you can do. One involves adding a small bottle of dye to the oil if you can see oil on the engine. After driving a short distance, you search with a black light. The dye will show up as a bright yellow stain that you can follow to the source of the leak.
A better test involves a "smoke machine" that you might be able to borrow from an auto parts store that borrows or rents tools. You inject the white smoke at 2psi into the dipstick tube, then watch where the smoke comes out.
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