I'm getting a high frequency (but medium'ish pitch) noise coming from the front when I accelerate. Doesn't seem to happen as often if I accelerate slowly and smoothly. I do not get the noise by revving the engine in neutral or park while at a stop, so it seems to only happen with the engine under load. Could it be an engine/transmission mount starting to go? It's sounds much different to the noise I would get when the mount under the battery would fail and make the vibrating noise, although seems to happen in similar'ish circumstances. Perhaps it's the mount on the side opposite the battery? Could there be anything else causing a noise like this?

 

Where in the front is it coming from?

 

Mine does the same thing sometimes - started after I changed the clutch. Not sure what I disturbed... and I have no idea how to track it down.

 

I would say it's coming from the right'ish side of the car? in the alternator belt area maybe?

 

loose heat shield? or maybe one of the bolts on the alternator??