What does a bad flex plate sound like?

My teen sons project BMW E39 525...after replacing the trans...is making a noise that I have been having a hard time tracking down. I have removed the trans twice trying to figure it. So, today I put the trans back in the car and took a video.

When I had the trans off the last time I visually inspected the flex plate for cracks and obvious signs of issues, but didn't see any -- although I did not remove the flex plate from the crankshaft. It's a two piece type design. It's a thin metal triangular piece that is held to the geared part via the crank shaft bolts. (like this. Not the actual unit)

I was wonder if some of you are familiar with this sound and issue. The first part of the video is in normal speed, and the second part is in slow motion. In slomo, you can see a relationship between the flex plate flexing and the sound.

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https://youtu.be/WARxQZS7b4U

Had one on a Chevy truck with a similar sound.  There was a loose bolt, and every time it spun around it smacked the dust shield.  Look for something with a shiny rub mark before you decide the plate is flexing.

In reply to tr8todd :

Thanks. I looked for evidence, but didn't find any.  But, it's obvious that I missed something LOL. I think I am going grab another flex plate and swap this one out to see if it solves things

I bet you when it comes off and you flip it, you see the crack.

In reply to Ranger50 :

Now I am wishing I would have went ahead and removed it when the trans was off, but I am getting good at removing an E39 trans LOL

I did not listen... but a cracked F P and a loose TQ CONVERTER CAN SOUND JUST LIKE A BAD CON.ROD

This was mine. Sounded like a -nasty- lifter noise from down low:

Here's mine.  It was remarkably quiet until it wasn't, at which point it made a noise like all of my dead Harbor Freight hammers had returned from the underworld to haunt the inside of the bellhousing.

In reply to SkinnyG :

Oh! Being somewhat new to these automatic transmission issues, I realize I really should have removed the flexplate rather than trying to eyeball it on the car. Now for another trans removal. This time I think I will time it. I bet I can remove the trans in less than an hour now. (the silver lining)

In reply to ¯\_(ツ)_/¯ :

WOW! That is impressive...Was it still in place when removed? Could the car still be started?

In reply to vazbmw :

It started fine and even drove into the garage!

Something is either loose, broken or bent.  There shouldn't be anywhere near as much runout as you have.

In reply to ¯\_(ツ)_/¯ :

WOW! 

Impressive

In reply to APEowner :

That's what thought. I check runout whilte turning by hand. It was a few weeks ago, so I don't remember the measurement. But, it was small. With the engine running the runout is obvious. Nothing is bent, so I am guessing there is a crack hidden behind the triangular piece

The last one I broke almost made a ringing noise.

In reply to AwesomeAuto :

I am now 80% sure it's my flexplate. It's even making a different sound today. Kind of a sliding metallic sound, which some times goes away. But I feel a vibration now