DIY 1.8T B6 Serpentine Belt Tensioner Replacement/Diagnosis

[surfntomm]

One way to determine if your tensioner is failing:

If you hear a clicking/rattling noise while idle and it is only heard while idling or rev'ing the engine from idle. This may be a common sympton but to verify that the serpentine belt tensioner is the culprit take a screwdriver or similar object and apply some force to the knob on the side of the tensioner arm seen here while the engine is idling. This will effectively provide more preload on your belt but also eliminate the chatter caused by your failing tensioner and the sound will disappear. Please note that this may also silence a noisy relay roller also known as an idler pulley. This should be easy to see with a flashlight to see if it is loose.



*alternatively an 18mm may be used to securely move the arm via this knub on the tensioner arm.

Tools Needed:
1 x Audi Serpentine belt tensioner MFG P/N- 06B903133E
1x 13mm ratchet wrench
1x Vise grip or pliers to remove pin holding tensioner arm in place.

Steps:
1: Remove 3 x 13mm hex bolts seen here where the red dots are (loosen the top one, remove the middle one, and lastly remove the bottom one. This avoids the tensioner bucking when you finally get your last bolt out)



2: Place new tensioner in place of the old one.
3: Fasten all 3 bolts (reuse the same bolts)
4: Pull upward as seen here on the side of the belt to help remove all slack from the belt and to ensure its engagement on all pulleys.



5: Once slack has been removed and proper engagement has been verified on all pulleys remove the pin using pliers or a set of vise grips. The pin should come out with a little bit of elbow grease but nothing alarming.

Hope this helps and feel free to edit this post as necessary

[coowhip]

Anyone know what size the Idler pulley 12 point is? I don't have a regular bolt but that stupid 12 point.

Do I need to remove the fans for this?

How easy is that to do without taking off the front end?

[MacFady]

Easy, 10 minutes from above, literally take out the three bolts and re-install, this DIY says everything you need to know (except torque specs ) . Removal is more cumbersome than install, you can use your fingers for the most part.

I'll just say it was easier to have everything right there sitting on top ready to go in so I could keep enough tension on the belt with my hand when taking out the last bolt and tensioner itself, that I didn't have to re-align anything when installing the new one. It helps to have a low profile ratchet option but you can do it with a regular 13mm spanner.

I thought the pin would be more difficult to remove, but I just latched on with vice grips, slip a long handle screw driver between it and the middle bolt on the tensioner for a little leverage and it popped right out.