Review on Mazda BP05 11 312 Engine Crankshaft Seal by Ron Chang

is well sealed. It turned out that my "crankshaft seal" was not leaking on the Miate. Instead, it was dripping from the oil pump dipstick hole. The same oil pump is used on many cars and the oil pump I supplied did not have a connector installed. The leaky hole is right next to the crank head, and that fooled me for a long time. I even twisted the handle. I bought an oil pump and wasn't aware that the pre-Miata Mazda 323 had a dipstick that went through the oil pump. If you have a very slow Miata oil leak, look to the right of the crankshaft pulley.