KA24E Engine siezed?

[Tieny]

Had a long 400 mile trip (6-7 hours non stop) the other day with my 89 240sx auto coupe (this is my daily; usually 50 miles a day). Once I finally got off the highway, I started noticing a slight knocking sound coming from under the hood. At first I thought it was my exhaust as it was half broken off but it was definitely coming from under the hood. Its not a consistent knock, almost sounds like a rattle. (i'll post a video of the sound in a bit)

Also while driving at normal city speeds I noticed an unusual vibration when my foot is on the brake and I can slightly make out hearing it. It felt and sounded like a grinding noise. (an example like brakes slightly rubbing against each other but in a slightly lower pitch.)

So left it until today, tried to start it up and it cranked really slow but still started up. Ran seemingly alright but that grinding feeling was a bit more apparent. And soon as I turned it off it won't start up again. (cranks once and then struggles cranking and stops)

I'm afraid the engine may be seized up but need some extra confirmation. Especially what that knocking sound was...

Thanks for any help

[kyral]

jack up the rear end, put it in 5th gear and get a buddy to help you rotate the tires. or put it in neutral and get a breaker bar with I think a 1 and 1/16th socket fits pretty nice on the crank bolt and rotate clockwise. try jumping the car too