Nasty Whistling sound

TheRedBlur

Active Member

Jul 7, 2003

15

0

38

seattle

Dec 30, 2008

#1

• Dec 30, 2008

• #1

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.

 

B

Brian@PAR

New Member

Sep 15, 2008

86

0

0

Phoenix AZ

Dec 30, 2008

#2

• Dec 30, 2008

• #2

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

中國製造

15 Year Member

Oct 31, 2006

5,525

943

214

Chengdu Province

Dec 30, 2008

#3

• Dec 30, 2008

• #3

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

Founding Member

Aug 20, 2000

1,526

13

124

Twilight Zone, TN.

Dec 30, 2008

#4

• Dec 30, 2008

• #4

Check your PCV connection underneath the upper intake too.

 

TheRedBlur

Active Member

Jul 7, 2003

15

0

38

seattle

Dec 30, 2008

#5

• Dec 30, 2008

• #5

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

Active Member

Jul 7, 2003

15

0

38

seattle

Dec 30, 2008

#6

• Dec 30, 2008

• #6

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

Founding Member

Jun 18, 2003

411

1

16

Houston (Bellaire) TX

Dec 31, 2008

#7

• Dec 31, 2008

• #7

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.

 

S

SleeperCreeper

New Member

Aug 31, 2008

2

0

0

Dec 31, 2008

#8

• Dec 31, 2008

• #8

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

Active Member

Jul 7, 2003

15

0

38

seattle

Dec 31, 2008

#9

• Dec 31, 2008

• #9

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.