Hesitation and Noise in 3rd

[Wurf]

As noted in my sig, totally stock and right around 2000 miles on the car.
Sometimes when I'm in it, and I grab third shifting very aggressively, right after I let out the clutch it will nose over for a second and I'll hear a "thump" under the hood, almost like a lean stumble backfire.

Any opinions on what this could be? On any given tank of gas it does this sometimes but not always and ONLY when shifter very fast.

 

[dread]

Sounds like it is your engine hitting the fire wall. Upgrade your motor mount and it won't do that anymore..

 

[Wurf]

I thought about that, but it doesn't really feel like a drive line lash thing. It's right after I let out the clutch at the bottom of third. The clutch is fully engaged and it's almost like I'm waiting for the motor to wake up for a tenth of a second or so, and then there's a mild boom or thump I can feel from the motor. Then it takes off.
If that's the mount, that's whack. I've been thinking about the CPE rear mm seriously lately.