New A/C idler pulley making noise

[aceventura]

I recently replaced all the idler pulley's on my VS with Holden parts.

-The new tensioner pulley is metal (works fine)
-The idler directly below the coil pack is identical to the one that came of it (works fine)
-The A/C idler is metal and included a washer as a spacer so that the metal guard does not hit the pulley

I fitted the pulley's checking there was no contact with the metal guards, but when I started the engine it started making a noticable metallic squeak. I narrowed the problem to the A/C idler pulley and went to Holden and they replaced it, even though there didn't seem to be much wrong with it. The replacement bearing felt exactly the same, and when I put the new one on and there was no difference.

Next I went to the mechanic to check I wasn't being an idiot, and it turns out that the noise is indeed coming from the A/C idler pulley. He is not sure exactly what the problem is, but said that he has heard similar noises before from VT's.

The A/C idler pulley does not mount as firmly as I would like, but I can't work out how to stop this. The mounting is new, cause I buggered the old one getting the old pulley off, so it shouldn't be worn.

Is the mounting the problem, or have I got two dud pulley's in a row?
Any other ideas?
Has anyone else experienced anything similar?

[aceventura]

Sorry, thought I could delete the thread and move it ... I was able to move it but I can't delete this one. Might as well leave the description here, in case someone knows what is wrong ... anyone?

[hako]

It could be the raised rubber ribs on the belt rubbing against the metal ribs on the pulley - try some chalk on the belt....this can quieten the noise sometimes. There also are belt lubricants but normally they are not required. You could also spray some water on the pulley that is making the noise when the engine is running...the water will act as a lubricant and if the squeak goes away then it will prove or disprove whether its the belt or the bearing.

[aceventura]

It could be the raised rubber ribs on the belt rubbing against the metal ribs on the pulley - try some chalk on the belt....this can quieten the noise sometimes. There also are belt lubricants but normally they are not required. You could also spray some water on the pulley that is making the noise when the engine is running...the water will act as a lubricant and if the squeak goes away then it will prove or disprove whether its the belt or the bearing.

Chalk, water, sound is still there.

Punch the bearing out, put a new one in, sound is still there.

The sound appears to be coming from the idler, but I think I will have to start searching elsewhere ... I'll post the answer once I work it out.

[hako]

The actual tensioner assembly will make a creaking noise 'normally' - if you watch the arm it moves in and out just a few mm and as it does this it creaks.

[moff_man]

the big metal washer is not needed with the metal pulleys, just dont fit it and i bet the noise goes away

[aceventura]

the big metal washer is not needed with the metal pulleys, just dont fit it and i bet the noise goes away

Hmm, the noise is still there but it definitely not as loud - good suggestion.

[aceventura]

It could be the raised rubber ribs on the belt rubbing against the metal ribs on the pulley - try some chalk on the belt....this can quieten the noise sometimes. There also are belt lubricants but normally they are not required. You could also spray some water on the pulley that is making the noise when the engine is running...the water will act as a lubricant and if the squeak goes away then it will prove or disprove whether its the belt or the bearing.

Hi Hako - Turns out I can't read instructions.

I put the chalk on the ribbed side - no change.
I also sprayed water on the ribbed side, not on the pulley making the noise. The back of the belt runs over the A/C idler, so the lubrication didn't reach where it was required.

Anyway clutching at straws I changed the belt and amazingly - Sound gone. If I had have sprayed the water on the pulley that I thought was the problem I would have identified the belt as the issue.

Thanks everyone for their suggestions.