Corolla making strange noises

[LeNeve]

I tried research on the web, and the only thing I found that makes the "warbling" noise, is the tensioner for the timing belt. I guess a carolla has a timing belt. You might want to get that changed as a preventitive measure too. I change the timing belt, and tensioner every 50,000 miles. Ford recomends every 70,000 I think. I have been left stranded a couple times in the last 15. That is why I change the belt earlier.