I just had the oil and filter changed a few days ago. Yesterday the check oil light came on. Took it back to have it checked. Turns out there was a hairline crack in the aluminum oil pan running vertically down from the middle bolt. It had been noted as a small lead around the bolt. The tiny bit of oil completely concealed the crack. The pan had not be whacked or damaged in any way. Now they're trying to find a replacement. Having the valve cover gaskets replaced at the same time. Costly, but essential to protect my baby. Sigh.