The car is a 90 crx. I hear this grinding coming from the lower part of the engine when you take it up to red line. The clutch needs to be changed, we think it is the throwout bearing. Is there any other possibilities?

 

I pulled a car apart couple weeks ago and the flywheel bolts had come loose. the pressure plate was rubbing against the inside of the tranny. I made the same kind of noise only all the time. Also my friends del sol had a piece of metal sitting between the flysheel and the block and made a grinding noise when revved. Couldn't find where the metal came from though. If it changes sounds when you push it the clutch it could be the bearing.

 

it could be the t/o bearing. change your oil you could have spun a bearing if you see alot of metal shavings you spun bearing. it could be a number of things