Timing Chain Tensioner Options

[palmer]

My sister has a 2003 Corolla CE, automatic. In 2007, I started to notice an oil leak, I do all the servicing on the car. The powersteering pump was starting to get covered in oil. I cleaned the area over the next 2 oil changes(10,000km) and monitered the leak. I told her to take it in and let them determine what was wrong(as the car was still under warrenty). They said the timing chain tensioner was leaking and replaced it. Over the next year and a bit there was no leak. It has been under 2 years since, and again I am noticing a leak in the same area, the power steering pump is getting covered in oil, and the tensioner is showing signs of leakage. I told her to take it in again and find out if it is the same leak. She told them to check the same area, and they are now saying it is the timing chain cover that is leaking, a repair that they quoted over $600 to repair. Is the timing tensioner a common problem on these cars? I do not believe that the cover is leaking, as there is no oil on that side of the motor, it is all on the back side. I even put a die in the oil before she took the car in to help locate the leak. Anybody else have a problem like this? Hope nobody takes this seriously, but I am more of a Ford guy(Iown a 08 Focus). Any help would be appriciated.