I've noticed a weird humming noise when I'm accelerating in 4th or 5th between 50 and 60mph. It's hard to explain and I can't quite figure out where it's coming from. As I said, it only happens when accelerating and will stop when I take my foot off.. it also vanishes as soon as I hit 60 and up. I've noticed it for a few months and it seems to be getting louder and happens more often (it used to only happen at 55, now happens at 50). I also notice the same noise sometimes in 3rd at about 30mph.

I drive an 02 WRX btw. Anyone know what this might be? It's just annoying me!

 

Does it happen at certain revs?

Could be a vibrating heatshield

 

Doesn't do it in any other gear. I took it up to 60 in 3rd and there wasn't a hum, so it only seems to occur in 4th and 5th..

 

In that case im not sure what it could be.

Im sure someone will come along shortly with some suggestions