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Audio of Rattling Noise When Revving Engine

I took my car to PepBoys (I know, first mistake) over the weekend for some issues with the car starting and a rattling noise that can be heard when accelerating. I made a voice recording of the noise when revving the engine in park (it also makes this noise when driving and changing gears… automatic trans if that matters). I picked the car up last night after $1500 in various repairs. It started perfectly and I didn’t hear the rattling. Today, it took almost ten times to start the car and the rattling had returned. Here are two audio clips (MP4 and WAV) from my Dropbox account. Can someone help shed some light on what this may be?

MP4: https://www.dropbox.com/s/j24of7dlogw986u/Car%20Noise.m4a?dl=0
WAV: https://www.dropbox.com/s/6ixu0yw0crzohum/Car%20Noise.wav?dl=0

PepBoys said on the receipt that they had replaced the starter assembly / reman starter and “repair exhaust”. Any help would be appreciated!!!

Would the engine crank, but not start? The rattling sounds like a heavy metal object hitting a metal part. Maybe the flex plate is loose and hitting the inside of the bell housing, or the new starter failed and the pinion is hitting the ring gear on the flex plate. Can you get it back to Pep Boys?

Maybe the torsion damper is loose at the front of the engine. Can you stand in front and tell which end of the engine the noise comes from?

Make sure to ask your shop to check the cat heat shield. That’s a common source of rattling noises. I expect you alrealdy know that it shouldn’t take more than 1 or 2 attempts to start the engine, so you got another problem of some kind going on.