Have someone try the starter while you watch the engine. Do the drive belts spin? (Alternator etc) If so, then it might be the timing belt. But that doesn't sound like "something small". It just cranks fast without the sound of coming up on compression.
Flywheel worn on that spot...
Use a 17mm socket in the middle of the crankshaft pulley to turn the engine. Only turn it forwards - that is counterclockwise as you stand alongside the left-front tire & look at the crank pulley.
Or put it in 5th gear & push the car forwards a bit.
'05 Saab 9²x aero (RIP)
2 '07 Civics
'09 Saab 9³ss
'10 Saab 9³sc