High pitched whistle
Thread Starter
Team Owner
Joined: Nov 2001
Posts: 45,000
Likes: 586
High pitched whistle
I have had this issue for quite some time and I cannot determine the cause. At full throttle just before the next shift (it's an auto) I hear this high pitched whistle almost like a waste gate sound. Once it shifts it is gone. There is no way to be under the hood and under load at the same time so I have to rely on guesses and forum member's experience. Any ideas? It is not speed related but is RPM related. At full throttle any other time, it is not present or not audible. It is at the 1-2 shift that I hear it. It may be from 2-3 as well, but I am not wound out like I am from 1-2. I tried recording it with my phone but the ambient noise is way too loud.
Melting Slicks
Joined: Jun 2003
Posts: 2,170
Likes: 48
From: Yuma CO
Senior Member
Cruise-In V Veteran
If, unloaded, idle hangs a little high or is a little slow to return all the way down to idle, then I would guess you might have a vacuum leak. This might also explain why you get a whistle at high RPM's from it, although actual intake manifold vacuum is usually at its lowest with large throttle openings.
Just a guess, but maybe something to look for.
DSTURBD
Just a guess, but maybe something to look for.
DSTURBD
Melting Slicks
Joined: Jun 2012
Posts: 3,163
Likes: 6
From: Oceanside California
I think it may be a vacuum leak at the intake. You would hear it squeeze by when the pressure changes during the shift. Its most likely happening on all shifts too, but not as noticeable.
Thread Starter
Team Owner
Joined: Nov 2001
Posts: 45,000
Likes: 586
The car is bone stock. I bought it with 13k on it so the problem has been around for a while. Now at 37k. How would I go about finding an intake leak and would a smoke machine find the vacuum leak?
Pitch get higher as RPMs climb.
Pitch get higher as RPMs climb.
