07t

I started my 2007 scion tC today and for some reason it started whistling while idling (it wasn't doing it last night). I then put it in gear and it seems like the higher the RPM the louder the whistling gets. I can tell it is coming from the engine but I have no idea what it could be. It is routinely service and maintained.

jct

sounds like a vacuum/air leak some where

TRaViESA760

My car was doing that not too long ago... and later that same afternoon my power started to shut down. Turned out my alternator and battery both needed to be replaced

TTCCC

My bet is a vacuum leak.

jkois

That is definetaly an alternator issue. Specifically the diode block will make that squealing noise as the diodes go bad. Change it before your wreck the battery as well.


FYI,
Vacuum leak would be opposite from his issue. It would squeal loud during idle, completely go away as engine speed increases if it was a vac leak.