The last couple of times I went out beetlebuggin, there was a terrible clattering coming from under the car. It definitely sounded like sheet metal rattling and would only happen when going over an especially rough patch in the road, like railroad crossings.
I still don’t have a garage or a lift or even a paved driveway, so it’s still a challenge getting decent access under the car to investigate. I went around, man-handling all the fenders, doors, and running boards, but couldn’t get anything to make a sound. I jacked up each corner and got each wheel off the ground, one at a time, and couldn’t find anything.
There is a drainage ditch at the end of my driveway and I have found that straddling the car across it gives much more (safer) access to the undercarriage.
From under there, I was able to find that the bolts connecting the heat exchanger to body heater pipes were missing and those assemblies were just loosely flopping around. There is a threaded bracket on the undercarriage, but I wasn’t able to find a bolt to fit, so I did the right thing and zip tied them snugly in place. The hose clamps were really loose, so I got them tightened up as well.
Took a little test drive and the clanging didn’t happen as often, but was still there on more extreme bumps in the road.