Cleaned the engine and determined the location of this oil leak. I am posting two pics. The far away shot shows the leak in the center of the picture...near the motor mount. The close up pic u can see the leak coming from a vertical seam just Below where the half shaft enters the transaxle. It is definitely motor oil, not transmissioin oil. I hope someone can shed some insight here as to how to fix it. I'm afraid it's not going to be easy. Any help appreciated!!
I suggest you verify that the leak is not originating from the valve cover and dripping down the engine, which would be the easiest to repair. Another possibility is that the leak is coming from the cylinder head gasket, which would require removal of the cylinder head so a new gasket could be installed. If in fact the leak is originating at a lower point between the engine block and the transaxle, and is engine oil, then it is likely that the rear crankshaft seal is leaking. That repair would require removal of the engine and transaxle and separation of the two, to gain access to the seal. That would not be a cost-effective repair unless the leak is severe. Good luck.
Thanks Patrick. The oil leak is definitely originating at the lower point between the engine block and the transaxle. In the close up pic, you can see the passengers side half shaft going into the transmission. The leak seen in the picture originates exactly where you see it...it isn't dripping from anywhere, it is seeping through the block and transaxle. I wish it was coming from the valve cover gasket after you saying engine removal was required to repair! I can keep adding oil I suppose---I have 219000 miles on this 07 prius!
...you can try Mobil-1 "high mileage" or possibly Pennzoil high mileage formulations which have extra dose of leak prevention (zinc?) additives. The only thing I can say is they claim to have added more leak prevention additives, but I am sure no one is promising miracles. The good news is you don't need as many oil changes since you are constantly refreshing. The bad news is of course, the groundwater contam. Mobil USA | Car Engine Oils | Product Comparison Chart (The Mobil-1 High Mileage gets three checks but I don't have that chart handy)
