My 1999 Mitsubishi Eclipse starting
shaking one day and then the next day when I went to start it, it started
screeching. Now, it currently struggles to start and when it finally does start it
makes this terrible and loud
screeching noise that stays constant. The screeching does not go away
regardless of what gear it’s in or if it’s
idle or driving. It is NOT a belt and the reason I’ve come to that conclusion is
that currently the belts are off and the only thing that’s there now is the crank shaft and it still screeches every time
it’s started and running. Please help
me with any advice or suggestions you have.
Thanks 
Timing belt shredding?
If the noise is coming from the front of the engine it may be from the timing belt tensioner pulley or the water pump. If the noise is from the front of the engine remove the timing belt cover and inspect.
There is also an balancing belt behind the timing belt that requires replacement too.
Check the engine oil level first. And make sure that the engine doesn’t overheat doing your ‘no belt’ experiment. That could easily happen if you’ve disconnected the drive to the water pump, even just idling in the parking lot.
If the water pump is still working, that can cause a noise like this. A locked up AC compressor or alternator could too.
I think the most likely cause is what the experts above say, the belts still remaining, something amiss w/ the timing belts and pulleys and idlers. If so, this needs immediate att’n. Best not to try to start the engine until this has been determined.
Since you have removed the serpentine belt, the only remaining possibility is something driven by the timing belt. Get it checked out before it becomes a more expensive problem.