Nasty Whistling sound

[TheRedBlur]

I took my car out after having let it sit for a few weeks (bad weather). Now I'm getting a pretty nasty whistling sound, it sounds like a mix between a vacuum leak and a slipping serp. belt. So I got under the hood with some brake cleaner, hoping to find some external vacuum leak, nothing. Then I removed the serp. belt and started her up for a second, still the same sound. The engine has a high idle like it would with a vacuum leak, but when I shut the car off, the whistling goes away right as the engine stops, and becomes quieter as the rpms approach zero. Wouldn't a vacuum leak continue to whistle for a little bit after the engine stops turning? I also had some exhaust popping as I compression braked.

What do you guys think?
It's been a while since I've had to fix this thing, so my diagnosing is rusty.

 

[Brian@PAR]

If it is a vacuum leak at the engine it will stop as soon as the motor stops since there is no more vacuum. There are some devices that will hold vacuum but the motor will not.

I would take a close look at the PCV. It can be a source of a pretty big leak and it's pretty well hidden on an FI car.

 

[NIKwoaC]

Does it whistle under throttle? A dead Idle Air Control Valve (IAC) will whistle at idle when the throttle is completely closed, and will be louder if the idle is high.

 

[JH96GT]

Check your PCV connection underneath the upper intake too.

 

[TheRedBlur]

The IAC works fine. I'll check the PCV. I think I'll put up a vid too.
Bearings don't whistle do they, they rattle right?

 

[TheRedBlur]

pcv is fine. Sounds like a lower manifold leak but I don't see symptoms of burnt oil, probably leaking from the top part of it.

YouTube - 100 3299

YouTube - 100 3300

 

[BigHairyMonkey]

what kind of tb is on the car? i lot of people complain about throttlebody whistling at wierd rpm's, especially with the professional products.

 

[SleeperCreeper]

i had a very high whistleing/shreiking sound comin from under the hood, freaked me out, though somethin was really f'd up. check'd the belt, intake, etc. just turned out that two header bolts were like a half turn loose. go figure, didn't sound anything like an exhaust leak.

 

[TheRedBlur]

hmm, that could explain it the sound, but not the high idle.


BTW: I've had this motor for 1.5 years and haven't done anything to it in the past 4 months. The whistling I'm talking about is a new sound that it hasn't made before.