Anyone who would like to chime in regarding the sound depicted in the video link below, please do. I played this recording for my mechanic; he called it out as rod-knock and I don’t doubt it. This occurred out of the blue the day after this car passed it’s CA smog check with flying colors. It was running great, I pulled int the grocery store, came out, and when I started the car, it would barely idle, and under any torque, I got this knock. It’s an 89 740tT with 220k on it. Transmission leaks and the interior is fairly decrepit, so I feel like a full engine overhaul/ swap would be throwing good money after bad at this point, but it’s such a bitchin’ car that I wanted to solicit some Brickboard wisdom before making a move.