WTF

something like:

VVVVVVVRRRRRRRRRRRRRROOOOOOOOOOOOOMmmmmmmmvvvvvv

Like the "mmmmmmvvvvvv" is not as loud audible as the engine revving up. But when I listen closely, I notice it.

It's like a belt is too tight or something. I I hope my timing belt tensioners aren't bad.

Maybe more like:
vvvvvvvvvvvVVVVVVRRRRRRRROOOOOOOOMMMMMMMMMmmmmmmmm (engine has revved back down)mmmmmmmmmvvvvvvvvvvvvvv (after engine has revved back down)