Glad I found this forum, looks like a wealth of info here. This is my first post, so here goes:
I just bought a 2003 monte LS 3.4 litre. It has 112,000 kilometeres on it (canuck here)
I have a front end humming noise/slight vibration coming from the front end. It varies when I turn the steering slightly from side to side. I think it's a bearing or could it be out of alignment? The sound goes away almost completely when I track slighty to the right. Also when backing out of a parking spot, if i crank the wheel over all the way then pull forward there is a growling noise and my TRAC message comes up, but then goes away after a few yards of driving. This doesn't happen every time, though. Any ideas anyone?

 

sounds like the wheel bearing is going

 

If this pulsating feel when you press the brake petal, you probably need the rotors turned on front of vehicle, this should be done every time you install new brake pads.

 

Probably the bearing, they are fairly easy to replace. Autozone has a good writeup on how to do it and sells them for $90 with a 1 year warranty. Autozone will loan you the large socket you need to take off the axle nut.

 

I was having the same grinding noise after backing out of a spot, etc. It became progressively worse throwing ABS and TRAC codes. Here is what I did: I cranked the wheels and disconnected the sensors at the harness that connects the integrated wheel bearing assembly to the electrical system. Once disconnected, spray both male and female components thoroughly with electrical component cleaner (available at Oreilly, etc.). Wipe them off and reconnect. Fixes the computer erroneously misreading wheel speed, etc. and throwing lights. Hope it works.

 

id say wheel bering as well.....very common issue..