Loud whistling sound! Need help!

[jpouliot]

I purchased a 1970 Bronco from the original owner a few weeks ago. It hadn't been moved from the barn in 4 years or so. I've had to replace & repair many parts ( brakes, carb & entire fuel system as well as gas tanks)

However, there is this loud whistling noise that my we can't figure out. It happens at a minimum of 20 mph and only after the Bronco warms up for at least 5 minutes. It is very loud and can be heard from inside and outside the vehicle. It is very difficult to hear where exactly the sound is coming from, we can't pinpoint the location of the sound. The wheel bearings are fine and the speedometer cable has been lubed.

Anyone ever heard of anything like this?

 

[Broncofan76]

exhaust leak from manifold/headers?

 

[Jfromtn]

May be the u joints if moving .mine was making a chirping noise like yours.i pulled the drive shaft and replaced all the u joints and no more noise

 

[jpouliot]

Some one else suggested it might be the U-joints, @Jfromtn, did you experience the chirping after the car warmed up/at a certain speed? Or was the chirping constant?

 

[Jfromtn]

First it did it intermittent then it became constant once I started moving.easy fix

 

[DuctTape]

Vary with engine speed or just ground speed? Does it change pitch as you change speed? Try to eliminate variables then keep eliminating things until you track it down. If just ground speed it is either wind or something that rotates. If engine speed start hunting for leaks.

 

[Quick & Dirty]

Vacuum leak.

The ball in the double cardan joint may be dry after sitting so long. More of a chirping or squealing than a whistle though.

 

[rwill]

Had similar sound in mine when I bought it 15+ YEARS AGO , vacumn leak

 

[sprdv1]

Vacuum leak.

The ball in the double cardan joint may be dry after sitting so long. More of a chirping or squealing than a whistle though.

kinda what I was thinking too....