Noisy accessory belt tensioner?

2005 Passat TDI, 118K miles. Just to get this out of the way, I have already replaced the one-way alternator clutch pulley about a year ago. The fairly recent squealing noise seems to be coming from the accessory belt tensioner, but just wanted to check with people here that have much more expertise on these cars if there are other more common issues that might be something to check. OR, since it isn't that expensive, should I just replace it?

Thanks, Skelly

Take the serpentine off and spin the pulleys by hand. Do you hear any noises, is there any resistance? It quite probably is the tensioner pulley but depending on where the alternator pulley came from (eBay,Amazon) and the manufacturer, that could also be failing again.

First, spray some water on the belts to rule out a squeaky belt.

Accessory belt only drives the AC. Remove it and check if the noise is still present.

QuickTD said:

One accessory belt drives the AC. A second belt drives the alternator, cooling fan and the power steering.

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I reread his post. I was defining the two belts as Serpentine and accessory, but it does look like he's talking about the serpentine belt.

They are both accessory belts. Serpentine is just a type of accessory belt.

QuickTD said:

Both of my passats have needed new bearings in the engine driven cooling fan hub. Easy to feel the play in the fan when you remove the accessory belt.

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Yes, common bearing to have start making noise. When mine first went out I thought my turbo was starting to go, but it was this bearing.

Also try taking the belt off and starting it. If the noise is still there it's prob a bad Balance shaft chain tensioner, if it hasn't been replaced or deleted already.

Just replaced the tensioner on mine for the same reason. Bought the INA one for $50 instead of a VW for $200. INA makes it for VW. In fact the INA one is pretty much the exact same one. You can see where they milled the VW/Audi logos and part number off. On mine it wasn't the bearings. The pivot and strut were the culprit. The noise is gone, and the belt runs much smoother.

Thank you

My apologies for not thanking all of you for your suggestions sooner. 11 out of the last 14 days working 12 hour shifts. As soon as I have a chance to dig into the issue I will update. And, yes I did mean the serpentine belt. Again, thank you.

johnboy00 said:

Accessory belt only drives the AC. Remove it and check if the noise is still present.

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Finally got the time to try some the welcomed suggestions posted here. It did turn out to be AC belt tensioner. Thank you johnboy00, also many thanks to all of you.

Skelly