Sounds like something is hitting under my car. Happens when I go over bumps in the road, especially when my passenger side rear tire takes the impact. Doesn't happen every time of course, but enough to annoy the hell out of me. Noise gets worse when it is raining outside. Multiple visual inspections under the car have revealed nothing. Suspension looks fine. Shocks aren't leaking or anything. Tire pressure good. Tranny mount fine. Rear hatch doesn't seem to be the culprit. The only thing I can think of is that it's my exhaust hitting that structural brace that runs across the middle of the car, right up by where the Y connects with the cat-back. The noise seems to have started right after I put my Loudmouth on about a month ago. Shaking the exhaust under the car, or bouncing the car up and down does not produce the noise. Anyone else experience a similar problem, perhaps right after installing their LM??

 

Check out the alignment of the LM check all the way up and down it. Clearance around the underbody see where your hands fit and dont fit it could be bangin off something when you hit a bump real hard. My Hooker catback was bangin off my underbody right where it goes over the axle because my passenger side mount was all worn out and it was allowing it to move a damn lot. Also check your suspension bolts, possibly an LCA bolt coulda worked loose....definitely check for loose suspension bolts they are responsible for alot of clunking.

 

Thanks for the info. The thing that gets me is why would it become so much worse when its raining outside?

 

The exhaust hanger on my right rear broke a couple times and makes a hellish noise.

 

It's worse when it's raining because the wet rubber mounts and hangers allow for even more movement. Check you exhaust clearances all around, especially from the y pipe area and where the over the axle pipe passes over the panhard brace.