tapping noise in engine

i recently discovered a tapping noise coming from my engine but it will only

do it through the 3000 + rpm range and dramatic loss in power through that

range any one have a similar problem please tell me what it is

i think it is a valve or something in the head

Sometimes cheap gas can cause tapping or a knock. Don't know if thats your problem.

93 and fuel inj cleaner each fill so not that

Could it be a Fuel Injector failing under pressure? I wouldn't think so normally because a dying injector would typically fail off and on. I think when an injector goes it does make a tapping noise. How many miles on your Aurora and what year?