Drivers of some 2007 V6 Camry models may come into your store with a complaint of a slight, but persistent, oil leak from underneath the engine. One likely source of the leakage, says Toyota, is the interface where the bank 1 cylinder head, the engine block and the timing cover meet.
To make an accurate diagnosis, add some fluorescent dye to the crankcase and let it circulate. If the dye confirms that the leakage is coming from the interface between the cylinder head, block and timing cover, reseal the cover then add additional dye to verify that the leak has been resolved.