Help my Ford Dealer: Strange Rattle on Decel

[Old-Raptor-guy]

SOLVED
Turned out the torque converter was ballooning for an unknown reason. Swelling pushed everything out and was causing the flywheel to unevenly rattle on the spacer between it and the block. Here’s a pic of the spacer the tech just sent me.

Yea that is a weird problem to have if no one has ever messed with the engine/transmission before.

And I can see why you were concerned, that had to sound like shit.

 

[MAMiller44]

Yup. Tech was an old school guy who really knew how to diagnose and troubleshoot rather than just read codes. He said he couldn’t find anything else out of the ordinary, seemed to just be an anomaly of an issue. I bought it CPO in 2020. I’ve never had anyone inside there before and doubt anyone was prior since I bought it bone stock and with a clean record. Everything’s going back together now with new converter, spacer, flywheel, studs, etc. I got free installation of the new SPD downpipes + trombone resonator delete so not all is lost. Iz gonna sound extra nice when I pick it up and rattle free!