Thunk!

[Paul Hawker]

I have noticed a soft "thunk" sound coming from behing the drivers seat area with the top up.
Anyone else hear this.
Any ideas.
Could be the top mechanism, or rear suspension item?
Normally hear it when driving slow, and it is associated with going over bumps.

 

[SylvanSRT]

Make sure you top is secures by the latch behind driver side "roll bar" sometimes you need to hold top down and pull the lever up to make sure it locks the top in place. hope this helps. that or take the bowling ball out ofyour trunk.

 

[Brad04Mamba]

I had the same thing on my GTS. Turned out to be a can of beans that fell out of the grocery bag a couple of days earlier.

 

[Frank 03SRT]

Turned out to be a can of beans

I got to say it --- A Viper with a fart can exhaust!

 

[Black SRT]

I hear that "thunk" all the time, but then again we have a lot of squirrels in the neighborhood.

 

[Black SRT]

Paul,

The "thunk" you are describing could be driveline backlash. The below is copied from "Frequently Asked Questions" in the "Members Only" area of the website:

Question 11:
First of all, I LOVE this new machine! Here's the observation, and I'm wondering if others have experienced this. Second, third and fourth gears at "coasting" speeds, semi-gentle quick stabs at the go pedal are producing HUGE amounts of backlash-sounding driveshaft and differential noise, much like used up GM muscle cars or a 12-year-old 928S4. Any comments?

Answer 11:
The noise you are describing is normal. What you hear is the driveline backlash that occurs as a result of the significant levels of torque being managed by the driveline. This noise is normal.

 

[Leonard Knight]

Paul:

I get that thunk sound too but mine sounds like a shock mount loose or body parts rubbing together. I hear it most when going over uneven surfaces like the body parts are flexing and rubbing or some suspension part is lose. It is definitely not the driveline though as I am familiar with that one from my older GTS.

I hope to find it one of these days and if I do I will post. Please do the same. It is very annoying.

 

[GR8_ASP]

Not sure but I am betting that the thunk heard is the crossover exhaust hitting the underbody tray. That is thunks heard when hitting a bump versus those when accel/decel.

There is a TSB for the exhaust issue. Don't know how to access the TSB's but I saw it as I was trying to trouble shoot mine. Mine was not able to be covered by the TSB as I modified the exhaust. Getting the crossover positioned just perfect is absolute.

 

[cstegall]

There is a TSB out on the "thunk" issue. Exhaust problem posted in September of '03. Dealer should know about it...my ViperTech fixed mine.

CStegall

 

[cstegall]

http://www-odi.nhtsa.dot.gov/cars/problems/tsb/tsbsearch.cfm

for TSB info.

CStegall

 

[Paul Hawker]

Thanks guys. The shock mount or exhaust sound like possibilities. Definitely not drive line.
It thunks when going over bumps, even backing out of the driveway.
Anyone else have more information?
The nhtsa did not list anything that sounded like it.

 

[cstegall]

Paul,

On the site above click on "get summary" and it will note that there is a noise while driving the car(under exhaust concern). If you would like, I can put you in touch with my ViperTech.

Clark