wmglaser

I have a 2000 TA 6 spd. EGR and Air pump delete. Just today I started hearing a whine from the passenger side engine, sounds like on top end. It only does it at 1700 to 1900 rmp. If i rap the enginge as it spools down it does it. When drive and slowing down to this rpm does it. Does it in neutral with clutch in or out, does it in all gears or neutral. Does it rolling or sitting still. Already changed idler pulley. Doesn't sound like coming from A/C compressor. Could it be the collector rattling on the header? I was told I have a bolt missing out of the three. It has been this way buy no noise until today. Almost sounds like a fan hitting a shroud if that makes sense? Not a knock or a hit but fan coming into contact with shroud or maybe flywheel coming into contact with dust sheild????? Any ideas or help would be greatly appreciated.