Ok, all you plumbers, both professional & amature. My bathroom toilet has been making this god awful whine when I flush it. I tried to get video, but of course the whine isn't nearly as bad as when I'm not trying to video it. I've narrowed it down...it's the water inflow. How do I fix it? Second, I don't think the water to the tank has EVER been turned off in the last 20 years, and I can't budge it. What should I try? WD40? Coke (as in cola)? It's kind of awkward to get to because it's next to the vanity which doesn't help matters. Third, I think I need to replace the valve (?) because I think I have a slow leak. I'm sure I can handle this but in light of my other two issues, do you think it's best for me to get someone to do this for me?