Is your transmittion a manual? The leaking oil is a leaking seal or gasket. The lack of power in 3d if it is a manual transmission most likely a broken ring in the engine. The F 134 will not stand high RPM's. 4000 is max try not to exceed 3000 RPM's. A broken ring will cause a lack of power. It is not evident at first but will get worse and score the cylinder walls. If you have a automatic transmission then a lack of seals could cause this.