I've got a buzz!

[KWBum]

So, my '92 SVX has a buzz.

Whenever you accelerate, it buzzes, almost like an electric motor. It doesn't really increase, or get too much louder, with speed. It just, well, speeds up a bit.

And it doesn't matter if you are accelerating slowly and gently, or hard and fast.

Any ideas what this could be? Or, indeed, if it's serious? Like a death rattle?

Thanks!