Torque Converter issues

[Litchkar]

how can you tell if the torque converter is failing? when I start my car, I have a rattling noise until the rpms get above 1,200. I just rebuilt the motor because it was making this noise thinking it was the motor, but it is still there. When I shift to drive, the rpms drop to about 500, then go back up. It’s a 340 with a 727 trans, stock stall converter. I have swapped out every part on the motor and I am running out of options.

 

[moparlee]

I don't know what a failing torque converter sounds like, but I do know that if the flex plate to torque converter bolt heads are making contact with the dust shield it will make that same sound. Check that out first and at the same time if any are loose.

 

[Litchkar]

I will try that tomorrow when I get off, that would be a simple and cheap fix.

 

[Litchkar]

I removed the cover, check the bolts, but still the same sound. Sounds like a box of rocks at idle.

 

[moparlee]

I removed the cover, check the bolts, but still the same sound. Sounds like a box of rocks at idle.

So the bolts didn't look like they were hitting on anything? Maybe someone else will chime in with some ideas and hopefully not anything serious.

 

[Litchkar]

Yesterday I found what looked like a torque converter bolt on the garage floor. Went under and found all the bolts were loose and one was out. Applied Loctite blue, reinstall them and the cover. I let it set a few hours and it started and purred like a kitten. I never would have figured it out Moparlee’s suggestion.thanks to everyone who commented.