Whistling Noise In Engine Compartment.

[elmor]

A few weeks ago I started hearing a whistling in the engine compartment of my 05 LeSabre. I had a broken clip on my MAP sensor so I replaced the PCV valve, MAP sensor and clips, hoping that it would fix it. Turns out that wasn't the problem. I've noticed that the whistle is loudest at idle and when you shut the engine off, it takes a couple of seconds before the noise stops.
I'm not sure if it is vacuum related or not. Could the EGR valve cause this? The car seems to run fine otherwise.

 

[ulycyc]

3 places to check. Power brake booster, HVAC fan or engine cooling fans, Pull the fuses for the HVAC fan first then the cooling fans fuses. If it still whistles pull the vacuum hose of the booster and plug it then start the car. If you have air level ride pull that fuse also.

 

[RD_Atlanta]

High pitch tones are so difficult to pinpoint. Perhaps there could be some carbon build up around the throttle butterfly valve resisting flow just enough to create a harmonious whistle tone when the throttle is closed at idle? Maybe try cleaning the butterfly valve area and IAC passage?

 

[ulycyc]

He said it make the noise happens after the motor is off.

 

[RD_Atlanta]

He said it make the noise happens after the motor is o

Right, if I understand his post correctly, while at idle and "it takes a couple of seconds before the noise stops". I have five LeSabre 3.8L's in my family and on all of them, you can hear air passing through the throttle for 1-2 seconds after shutting off the engine. I assume this this is possibly the post engine shut off period of time that he hears the high pitch whistle.
Of course, what I'm suggesting may not be the cause but it's something cheap and easy for him to check.

 

[ulycyc]

Best if he clarifies "when the engine is off"

 

[02LTD2.0]

PCV spring....Make sure your PCV has everything sitting right.
O-rings and spring. Go back and check your work.

 

[02LTD2.0]

More Information for GATES EMH999

 

[elmor]

Best if he clarifies "when the engine is off"

The noise happens when the engine is running and when you shut the car off, you can hear the whistle fade out for a couple of seconds before it stops completely.
Yes, the noise is hard to pinpoint. I think it's coming from the driver's side of the engine. Would a leaking EGR gasket cause this? I will pull the power booster hose and see what happens.

PCV spring....Make sure your PCV has everything sitting right.
O-rings and spring. Go back and check your work.

The PCV is sitting where it needs to be. New hose, new spring, new O-rings, new MAP sensor.

 

[silverbullet04]

Check the rubber grommet on the map and make sure its on properly.

 

[elmor]

Weird stuff! I fired up the old LeSabre today and it whistled as usual. Drove to my daughter's, which is 60 miles each way. The car whistled all the way there; I could hear it every time I slowed down or came to a stop. Shut it off for 15 minutes and when I fired it back up, no whistle! We drove around and did errands and every time I started the engine it didn't whistle. ????? Guess we will see what tomorrow brings. I don't have a clue why it would make noise for weeks and then suddenly stop. Runs great. Best $300 car I ever bought.

 

[02LTD2.0]

300 is about the price of scrap these days. You're lucky it runs and shifts okay.