Morning everyone, hope y’all are doing well. So I tried to crank the rx7 for ***** and giggles and it’s making a sound I don’t recognize when the key (screw drive in this case) is turned to start the engine. No crank from the starter or anything just a weird rattling noise. I’ll attach a video below if anyone can maybe point me in the right direction as to what that sound is please let me know. Thank you and have a great day.

 

I can barely hear it.. but what comes on first when you turn the key is the fuel pump I think. Maybe the mounting bracket for the pump is loose?

 

sounds like fuel pump to me. it's mounted under the driver's side, just forward of the rear axle. yes, sometimes u will hear them. u really don't hear them in cars today because they're inside the tank.

 

Did you ever figure out what was wrong? My rx7 is doing the same thing and the starter is not engaging.

I believe I hear the pump turn on when I turn the key, but I dont hear the starter.
Video of my rx7:

 

I replaced the starter and all that did was make the tachometer move, and throw a few more lights on the dash. Still makes that rattle I have no idea what it is sorry. Mine hasn’t started since 1987 and I think it’s stuck in gear so it’s a mess ngl.

 

Well then,
Check to make sure that there's 12v getting to the starter. low battery? Loose battery terminals? There's no fuse, so the only thing in the 12v line to the starter is the ignition switch itself.
I've had to replace mine, but only after 15-20 years.
Your voltmeter in the instrument cluster should read around 12v , then drop to about 8v as the starter cranks.