Rattle going over potholes

What about going over potholes while turning? Is it more pronounced? Or less? Or the same?

 

Sometimes a rattle like that can be related to a bad wheel bearing or problems with wheel assembly and noise changes while turning often will point to that.

Also... Have you spent much time examining everything underneath the car?

 

I had an upper shock mount rust out once on a Mazda 3.
Made similar noise. I think I was lucky the rod didn't pierce the body before I figured it out.
On the one hand, they salt our roads.
On the other hand, your car is 20 years old.

 

Yes! Exactly... Eliminating noises in a 20 year old car will make anyone crazy from failing too much. Some things about a really old car just can't be fixed.

 

Or person; I'm a living example.

 

Maybe secure the cable better and see if that changes anything?

 

Unless you can afford getting lots of work done... I mean Madonna is 68 years old and barely looks 50.

 

My thing was more of a big scary clunk rather than a rattle.

 

Yep... It's always a nightmare when people try to describe car noises. Near impossible to help people with stuff like that.

If you're living in an area with road salt I guarantee you'll find something under your car that is failing due to corrosion. Take it to person who replaced shocks and have them put it on a lift and try to find it.

 

OP took out the hatch storage compartments and noise still there. Sticking with the "inside the car" theme...

Was the spare out too?

Give the battery a shake and a lift, maybe the tie down is loose?

Pull the 12V battery out and see if there is anything loose in that well.

Check that the little energy storage box near the battery is firmly bolted down.

Wedge some foam under the rear license plate and/or any frame around it. These can make a surprisingly loud noise when they bang up and down.

Shake the wiper arm on the hatch and make sure it is not loose.

Gently shake the plastic trim in which the hatch release button is found. These are prone to breakage and could be moving enough to be audible.

Fold the rear seat down. (Not sure how this would make a noise, but it can move, so, best to rule it out.)

Shake the exhaust tube from the HV pack to the vent in the side of the car, verify that it is tight.

Pull out all the plastic to expose the HV pack. Check that all the bolts are tight and that there is nothing rolling around in that area.

If still no joy...

With everything out of the hatch area, seat a human in the hatch area on a cushion, and drive over bumps that cause the noise to appear. That person should be able to localize the source somewhat. Word of warning (from personal experience), a person sitting unrestrained on the rear deck of a vehicle can be thrown hard against the ceiling when going over a bump with enough velocity. (I was in the back of a 1970's era Bronco and my head, shoulders, and part of my upper back ended up flat against the ceiling liner. Not fun. Lucky I didn't break my neck. Pro-tip, don't go that fast, and have said person put at least one hand on the ceiling before going over bumps.)

Failing all that, one can buy little microphones to place around or under the vehicle. Some are wired, some are I think bluetooth.

 

Pro tip #2: Don't ask your wife to sit back there.

 

As per usual, the recordings didn't offer much insight... And you're sure it comes from the top part of the car not lower down? Have you inspected all the bolts holding the battery pack down? Bolts holding hatchback down?

Also try getting a stick or dowel and while someone else is driving hold one end to your ear while holding the other end to various part of inside of car to find exact location of the sound.

 

Do not do this! Listening through rigid objects is only safe if the thing that is being listened to is not suddenly going to kick that rigid object into your head. One big bump and that stick could be jammed hard into the ear - and it is perfectly positioned to do severe damage when that happens. A mechanic's stethoscope would be safe. Physically, because there is slack in the listening tube. However, it might be very loud.

 

Lol... Thanks for pointing out basic common sense... As well as pointing out my point: If someone is way too overly obsessed with finding a barely noticeable sound in the back of their really old car got injured in the process of doing so: it's well deserved! Also would be kinda funny! Sometimes that's what it takes for people to focus on way more important stuff in life.