Vroom vroom!

[cubewhiz]

So starting today on my way home from work, when I let off the clutch (foot also off the accelerator), the RPMs climb a few hundred for a second or two before dropping back down.

For example, going 55 on the highway, let off accelerator, wait a few seconds, foot on clutch, RPMs climb like 300-400 and stay there for a couple seconds, then fall.

What could cause this?

Thanks.

 

[adsm08]

IAC probably.