Since this could impact any generation, and no responses from 5th gens, trying the General Discussion...

See description and video here: https://maxima.org/forums/5th-genera...vibration.html

 

Have you tried pulling up the carpet to see if the sound is coming from the seam? I'm inclined to agree with your assessment of a failed weld but it needs to be verified.

 

Yes.

So far I had removed all trim and carpet for visual inspection as well as used a flexible inspection "snake" camera throughout the inside of the b-pillar. No anomalies found. This tells me the problem is likely a small issue that is making a big ruckus.

UPDATE: Stuffed the b-pillar cavity with rags and foam. This initially reduced the noise to a reasonable level, but it was still audible. Then, when the Arizona weather cooled down (below 100's), the noise reduced significantly. Not sure if the weather had much to do with it, vs. the filler material settling in. If the noise returns, the next move would be to line the area with dynamat.

Anyway, it's good for now....