Engine/Transmission (1994 - 1998) Newly developed Whistle

[MrWill12]

Just today on the way to work, a light whistling noise has developed, but only under acceleration. The whistle sounds like what you would make blowing across the top of your teeth and only something noticable to the person that drives it. (One of 'those' sounds)



I have no mods other than a 4" straight exhaust and the only thing I've done recently, two weeks ago, is a 20k mile air filter change. This is for a stock box, fleetgaurd paper filter.



I'm wondering if one of my boost tubes has developed a pin whole. They are the original tubes on a 97, Auto, 4x4, with 113k miles.



Any other ideas?

 

[JR]

Definitely sounds like a boost leak. Check any connections you may have recently had apart, and go from there

 

[MrWill12]

Cool. I'll add that to the list with the oil change and alternator rebuild.

 

[NIsaacs]

With the new filter change, you might just be hearing the turbo spool. A high pressure boost leak will usually be more of a squeal rather than a light whistle.



Nick

 

[Missouri Mule]

Could be a vacuum leak. How are your vacuum operated components doing?

 

[hsmith]

The most common place for a boost leak is the inlet boot at the CAC. It can rub on the frame and develop a hole. It also would cause egt's to rise and boost to drop. Not saying that is your issue but happened to me while towing.

 

[shoalsgary]

I developed a whistle at shutdown since replacing my governor springs.

 

[MHalloran]

Can we think it may be the turbo making this whistle sound you hear? I'm sure there are other guys out there that know what I'm talkin' about. I can still hear mine during acceleration although it has become more prominent since I removed the ring many years ago... ... ... ... ..... It's even more audible on some big rigs... sounds cool... ... ... ... ... ... . Mike

 

[Missouri Mule]

If it is high pitched it could be vacuum leak.

 

[MrWill12]

All vacuum operated components are fine. This was a lighter whistling sound not the normal turbo whistle. I had disconnected two vacuum tubes while changing the filter, but secured them after the change. The whistle has subsided for now, but I did recheck the vacuum connections again.