I was driving steady at ~3000 RPM's in 4th gear, when I immediately began hearing a chunky grinding noise from the engine. It was on and off for the first 20-30 seconds while the motor seemed to still be able to rev appropriately, then the noise became continuous until I shut it down.
I quickly grabbed my phone and recorded this video for reference.
1988 911 Carrera - Engine Problem on Vimeo
I'm anxiously awaiting for news of its condition; however, the shop isn't open until Monday. In the mean time, does anybody have an idea what this may be?

Cost?

I'm almost too afraid to ask.
I've always enjoyed reading the information that everyone shares on this forum and I'll appreciate any feedback while I wait.
Thanks!