Arsenii

Where is a CEL? The engine is off, the Check Engine Light must be on when the key is in the ON position without starting the engine, so it either burned out or was intentionally silenced. Use a scan tool to check for codes, see what you come up with.

The engine sounds like there is barely any compression it's just spinning, check the timing belt and that the timing marks all align, then use a compression tester to see if you have any compression at all. Below is a video of how it should sound.


Hope this helps and best of luck!

a1accord

Let me know if this is worth the trouble of trying to solve or if I should just throw a new engine in there.

LeX2K

That sounds like loss of compression.

Arsenii

That will be very hard to tell without seeing the car in person, my guess of it being low on compression is just a guess from the sound in the video, so I would suggest to check the timing marks and run a compression test before drawing any conclusions.

There are no codes stored in the Engine ECU, use a test light in the Diagnostics port under the hood, put one end to Ground, and another to Pin W, which is a duplicate for a CEL, see if it will light up, if not, you may have ECU issues as well.

Hope this helps and best of luck!