My wife drives a 2004 Mercury Mountaineer Premier that just turned 112,000 miles. It is the AWD with the 4.6L. I have been driving it for the past week to try and figure this out with no luck.

The problem that I am having is a wub-wub-wub sound that increases with speed and gets louder when turning left (initially it was only heard when turning left, now it is slightly noticable when driving straight as well as turning left). It is not the classic "clicking" sound of a bad CV shaft but a wub-wub that increases with speed as well. It seems to be coming from the front left or center of the vehicle (sound is really only noticable from inside the vehicle). It has gradually gotten louder over the past few weeks. Both front wheel bearing hubs were replaced about 6 months ago and the left rear wheel bearing was replaced about a month ago. The brake rotors do not appear to have any warping in them and they are not rubbing on the dust shields (all four replaced a little over a year ago). Tires are newer with about 10-15k miles on them.

In addition to the sound, over the past two weeks the ABS has been going off occasionally when moisture is on the roads (however it will not throw a code for me so I can get it checked with a scanner) and yesterday and today the Advance Trac dash light would blink occasionally and it would adjust something as I felt it engage when driving straight (on dry pavement) which is new. The Advance Trac light would not stay on, and the system would only engage for a short second and then everything would go back to normal. My wife did state that a little over a week ago it did throw an ABS code (where the dash light came on and stayed on) and then the AWD locks out and the Advance Trac shuts off automatically until the ABS light went out (when she restarted it later in the day coming home).

Thank you for any help as this noise has been drving me nuts for some time now.

 

sounds like you have another bad hub

Jack up the truck and shake the front tire up and down and side to side and see if there is any play in the hub

 

Already did that, no play on either side.

 

guess its possible you have bearing noise in the front diff

have you tried to rotate the tires around front to back? Ive heard tires making noise like that if they're all chewed up on the inside

 

I'm still at a loss. I have rotated the tires all around to elminate noise from one of the tires. Noise remains the same. Replaced the front wheel hub (in case it was a bad part) on the side that the noise was coming from, noise remains.

To top things off, now the noise is happening when I turn to the right as well (this just started yesterday). I guess it is time to take it into a mechanic as I am lost.

 

sorry I can't be more help over the internet