My Z's been making this thumping sound for a few months now, but only when the car been driven for about 20 minutes and warm up. The sound comes from underneath the car towards the rear. When I brake hard for a stop light, I hear a thump after 5 seconds, sometime I hear it when I accelerate slowly. To describe the thump, it sounds like a malet is being struck very hard underneath the car. The dealer doesn't know what the problem is because they don't hear when test driven. If anyone here has this same thumping noise, please help me locate it. Thanks

 

Does it thump while you are idle? It's annoying... lots of people here discussed it before. After accumulating more miles, the car idles much better than before.

 

I had a similar sound, like someone with a bat was under the car, it happened whenever I accelerated from a stop and sometimes from first to second shift, and it also started after driving the car a while, at first it just happened sometimes then it was all of the time. The dealer couldn't find out what it was, and now it has disappeared without doing anything, I got under the car and checked and found nothing lose so it is still a mystery to me.

 

The thump is like what Westpak describe. I didn't hear it when I first got the car, maybe after 8k miles and it's not going away. Yeah dealers don't know what it is.

 

Check to see if it's the same as this:

SERVICE BULLETIN NTB04-065
affects all 2003 models and 2004 built before 2-14-04

description part #
Bearing assy, rear 43210-AL505
Axel outer joint assy 39211-73L00
Repair kit, dust boot outer 39241-73L28