Land Rover Repair: 02 Disco - chirping sound, alternator pulley, serp belt

Question
I have an 02 Disco, and like so many of my fellow owners the "three amigos" (ABS, ETC, and HDC) are with me.  As frustrating an issue as that is, that's not my problem today.  My disco makes a kind of chirping sound.  It the kind of sound that I associated with a bad serp. belt.  However, this sound remains regardless of enging temp.  It seems to depend on load too.  I mean, if I am going up hill, rapidly accelerating, or no gas petal pressure at all, there is no noise.  It's also only audible at relatively low speeds (below 50ish) and with no change in acceleration (could be lack of road noise). Any thoughts or suggestions?

Answer
Hi Brian,

it could be a bearing that is about to fail.  Which bearing becomes the question of the day.  You can remove the serpentine belt and manually rotate each pulley.  This will reveal if a pulley bearing is at fault.  You'd feel a rough 'spot' as you turn the pulley.

Most times, in my experience, the bearing that fails the most is on the tensioner arm/pulley.  Next would be the alternator pulley.

I hope that's that cause and you find the fault soon.  When the noise begins to get louder...its not a good thing.

Best of luck,

JohnMc

NB:  it does not help that LR will not recognise that there is a problem with the 3 amigos.