I have this annoying problem that happens occasionally. I will sometimes have alittle extra whining from the engine during acceleration or sustained speeds/rpms. Saying Im coasting at about 2800 rpm... and the engine whine will be kinda loud sometimes which makes the engine sound like im coasting at 4000 rpm's... And i hate it! Sometimes i dont have any extra engine whining and I can almost hear nothing from the engine while coasting at 3000 rpms... It comes and goes.
FYI, i have 2 secondary air-injection CEL codes at the moment... maybe related?
Idles nice and smooth even during loud engine whining moments.
Sometimes burns gas pretty quickly during gentle driving and sometimes wont.
1997 Boxster, 115,000 miles Original Engine.
Anyone else experience this?