Can anyone identify this horrendous rattling noise?

[oldmansmonte]

'85 Monte

SBC, 200r4 with column shift.

It just started one day. Goes away occasionally but has gotten worse. I thought it was the column shift link bar because it touches the headers but I can use a screwdriver to move the shift link away from the headers and it still does it. Does it while driving too. Mostly while accellerating 0-40ish, after that it seems to settle. Any help would be appreciated.

 

[ELCAM]

Perhaps a broken flex plate.

 

[Dayzedandkonfuzed]

Perhaps a broken flex plate.

Or even just loose converter bolts. Had that a time or two, sounded very similar to this.

 

[oldmansmonte]

Or even just loose converter bolts. Had that a time or two, sounded very similar to this.

Yeah I’m going to check them out now. Definitely sounds like converter area.

 

[Ugly1]

Definitely check the dust cover for marks then all the bolts and flex plate for cracking.

 

[Ernest]

Ima take a wild stab at this and say..... muffler bearings. j/k

I've had this noise before and it tuned out to be a cracked flexplate for me.... but could be loose convertor bolts as well.

 

[bracketchev1221]

Going to take a wilder guess and say broken catalytic converter internals.

 

[Mac442]

Going to take a wilder guess and say broken catalytic converter internals.

Mine was making the same sound. Was broken honeycomb inside one of the cats…get a piece of rubber hose and with it running place one end right next to the cat and other end next to your ear to try to isolate the sound location

 

[nycutlass]

if a flex plate is cracked while the engine is running and in park rock the car aggressively front to back while doing so listen carefully is the sound progressives or not

 

[Local Hero]

Going to take a wilder guess and say broken catalytic converter internals.

That was my first thought as well. I had a convertor come apart internally and sounded just like that. I could even hear it rattle without the engine running, just by slamming the door.