Whistling noise at idle, then goes away, but appears at approx 2000 rpm.

[krusing]

2006 CX6 Adventra

On the weekend I had a very unusual whistling noise from under the bonnet, especially when I first started my car in the morning, being it idles at approx 1100 rpm when cold, then drops to approx 750 rpm.
And at approx 2000 rpm,
And first I thought, got to be a vac leak,
so I checked ALL the vac hoses, PCV pipes and everything was ok,

However, after the start up idle speed had dropped down to normal,
It sounded a bit more noisier than usual idling, sort of like metallic,
So out comes the mechanic stethoscope
(Dr krusing at your service )
Thinking it could be the Water Pump, Alternator, or the Power Steering Pump, or the 2 idler pulleys.

What I found was the Power Steering/Air Conditioner Tension pulley bearing was very noisey by using the stethoscope, it sounded buggered, and it was.
Removed the idle arm, and pulley,
I pressed it out, you could hardly turn the bearing,

Being I have spares on hand, 6203-2RS, (as they are very common idler pulley bearing)
Pressed a new one in,
and what a difference it’s made when idling, much quieter now.

 

[Immortality]

Yes.

I do pulley bearings every few years on the L67, I had a draw full of the 6203 bearings. I like to pop the seals out and fill with high temp grease.

If I had a lathe at home I'd make myself some new alloy pulleys and use a double row bearing instead. Not really a great using a single row bearing to support a pulley, especially the tensioner which seems to cop the most abuse.