I've got this wierd chirping sound that gives my car a "jolt"

At first I thought I was running over a large dry leaf or something, b/c that's what it sounds like and feels like a wheel just slipped momentarily.

But now it happens like every 30 seconds in stop-and-go driving.


I've been able to reproduce this sound by going into 2nd gear to 3000 rpms or above, then engine breaking. The sound and 'jolt' comes around 2000 rpm decelerating.


I'm absolutely stumbped as to what could be the problem, can anyone help?


Much thanks,
Ambert

 

does the car have spider gears, because my work van is awd and the spidergears go all the time in them, dunno though, I might not know what I am talking about, LOL

 

how is it when you are going around turns, they spider gears really get worked up then, thight turns, does the car shake?

 

spidergears? lol this is a wrx.

Yeah it was the AC, thanks all