Try to not give up although I know what you've gone through. When I troubleshot my 2004 Vibe Gt for it's oil leak, I had a lift available, a "snake" camera, and time. It took several attempts but I eventually pinpointed the leak. My engine has the Yamaha head on it and the three points that meet (block, head, timing chain cover) is where my leak was at. What started as a very minor leak at around 140k miles, progressively got worse until I got tired of putting something under the car every time I parked it. That may have been some 15k more miles roughly. Don't give up