In the last two weeks I've noticed a new whine coming from the front of the car. The pitch of the noise changes with revs rather than speed. I know this engine already is quite whiny, but this is a new noise that has developed recently. Initially, it only came after the engine had warmed up a bit (maybe after 5 miles or so) then would go after the engine had been working hard for 30 mins or so. Now, it seems to be there from start up and stays there the whole time. Any ideas? Timing chain issue maybe? Car has done 75k miles. Thoughts appreciated.