Not sure exactly what the problem is so I want to hear all the different possibilities.

Problem: whenever Im cruising or coasting (at any speed in any gear) and I bump the throttle to continue driving or accelerate there is a *thud* noise coming from somewhere behind me.

Mods: Built 4G64 2.1L w/ FP Black & supporting mods. AWD Motorsports tuned on 92 to make 450 to the wheels

I have owned an '03 and an '06 IX RS. I never heard or had this problem with either car though the RS had Shep trans and T-case. I don't beat on the car and I don't launch it ever but I can't speak for the previous owner(s). I did notice a small trans fluid leak so I have to throw the car up on the lift and find where thats coming from but thats a whole other problem.

Let me here your thoughts on what it could be. Thanks for your time.

Chris

 

Sounds like a lot of play in the driveshaft.

 

^^Yup

 

Loose/broken rear diff mount, or excessively worn bushing maybe?

 

Something loose in your trunk? Check the open areas in the rear fenders...Dead hooker stashed back there or something?

 

Nothing in my trunk, no liner, no spare and I got rid of the dead hooker and 4 kilos of cocaine a while back...

 

Is it absolutely a mechanical sound, or could it be your exhaust backfiring?

 

rear diff, driveshaft.. period.

 

definitely not backfiring...

 

rear diff mount

 

ever get this sorted out?