If this has already been posted then I'm sorry. I searched and didnt find anything so this might be new. Anyways, I've had the tC since end of Jan. and got my first oil change less than a month ago. Ever since that first oil change, when I accelerate I hear this high pitched whistling-type sound coming from the engine. I didnt notice it till after the oil change. I dont have an aftermarket intake or exhaust or anything. Everything is stock. If anybody would be of great help as to what that sound might be (good or bad) and where its coming from? I know nothing about cars and their mechanical work so I'm clueless. Any help would be appreciated

 

It's the stock airbox. The sound is more prominent after a few miles. I actually like the sound... gives it a little something different.

Nothing to worry about though.

 

Its normal, nothing to be worried about at all.

 

I just noticed that same high pitched sound yesterday (200 miles on a 2006 tC). The funny thing is, it happens even if you remove the top half of the intake/maf assembly from the airbox, effectively bypassing the main air filter. I wonder if it has something to do with the secondary air filter (very thin layer of cotton/wire mesh) that's built into the inlet of the maf?

Ravi

 

More info: https://www.scionlife.com/forums/viewtopic.php?t=56412

Search works wonders, btw.

 

I believe the whistle is actually the throttle body. I have the K&N CAI on my tC and I still hear the whistle....but it's louder. I think it sounds cool....but hey, just my $.02

 

well.. i have my theories aswell......... and one is the throttle body... but the other is another peice that does not change even if you go to a CAI... and that is the MAF/Air temp sensor.. if you have ever really looked at it.. there is a cone that will cause a difference in air pressure on either side.. sort of works like a straw..would work.. if you sit long enough and think about it.. you can fegure out how the airflows thru the sensor..

in short.. that cone in my opinion could be the cause of that whistle once the air flows thru it at a certain volosity.. just another theory.. but the airbox it is not... other that have replaced the box still get it.. so....

 

well, i got into an accident and kind of exposed the driver's left bumper and fender.. and i can hear the sound a lot more clearly... AND there's a lot more noise from 3K RPM on up. it's sweet... minus the huge whole in the face of my car.

 

i had the same whistling noise... the dealer said they didnt hear it so i had to ride with the mechanic.... after holding it for a day they found the problem... the seals and moldings around the front of the window and moon roof are defective.... the wind slips in the seal and the noise is the riber vibrating againts eachother and the glasss like a cheap ****.... im waiting for a call this week to bring my car in... parts had to be ordered..... my noise came in when i reached about 60 miles an hour

 

^^^ no its not, we are talkin about something totally different

 

correct this has soemthign to do with the intake system

I totally agree that is a wind noise from the top not the engine compartment

 

http://home.cfl.rr.com/icdedppl/faq.html#f1

this has been discussed numerous times. use the search or use the faq.

 

da da da da! icdedppl comes to the rescue again!