I have a 1986xr7. She's still pretty stable but she's making this god awful "siren" sound, upon acceleration. She shifts fine so I don't think it 's the tranny. But that's how loud it is. People think they're getting pulled over. Quite embarresing. I've been told multiple times that it's my turbo but I've got no clue as to where I'm looking or what I'm looking for.???? Any suggestions?