Supercharger + power steering belt destroyed.

B8 S4
#1

Drove to work yesterday and parked. Got in a while later and all of a sudden my power steering was acting up.
Switched the car off and popped the hood. I checked power steering fluid and all the belts. All seemed good.
Took it for a short spin around work for a quick test. Power steering was intermittently working. Decided to rather drive home and book it in at Audi. On the highway all seemed fine.

I overtook some slow ass drivers and i had less throttle response as per normal, popped it in a lower gear and gave it a little bit more of gass. All of a sudden u could hear the whine of the charger as it would always make. (Got the airbox off at the moment)

As i got to about 400 meters from my house all hell broke loose. Belts destroyed themselves, huge noise in engine bay, Alternator light came on, Water temp warning came on. I immediately pulled over and switched off the motor. The water temp was around 95 - 97 dec.

Had it towed to my house and started stripping. Lots of pieces of old belts all over the show.


http://i17.photobucket.com/albums/b89/DirkieUys/IMAG2626_zpsl7fw7lnx.jpg


http://i17.photobucket.com/albums/b89/DirkieUys/IMAG2606_zps7w7ytyaa.jpg


http://i17.photobucket.com/albums/b89/DirkieUys/IMAG2605_zpso5eisu5t.jpg

After getting it all cleaned out I found that the Crank Pulley’s outer was loose. Its secured onto the cranck with 8 Allen key screws, and that was all tight.

Check the video link to see what it looks like.
http://youtu.be/UEoEVFvhSBE

I’m going to replace both belts, both pulley tensioners, both pulley guides and the crank pulley.
Parts come to 580 Dollars. It could have been worse

I spoke to a fellow S4 driver locally and he said the exact same thing happend to him 2 months ago on 120 000 kms. Mine is a 2010 model, sitting on 104 000 kms. Has this happend to any one before ?

Mods on the car:
MRC software
APR intake
APR CPS
IBF Pulley
Miltek Non Res exhaust

#2

wow that sucks, glad its only belts. I guess we need to start checking if the main pulley bolts are tight. I think the other instance of this happening was the pulley came apart in 2 pieces from the rubber damper.

#3

I agree. I think it was the crank pulley seperating and mis alining the belts. I’ll take it off tomorrow evening and take some close up shots. Have to wait a week for the parts.

#4

Wow that is a damaged crank pulley for sure. That would be the cause I wouldn’t worry too much about any issues from the belts coming off. The only thing that kinda sucks is that if mm it happened to you and one other guy it will probably happen again at some point.

Maybe try contacting JHM and see if they will make a light weight crank pulley for it. The v8 s4s needed a crank pulley made when they put on a supercharger.

Try v8@jhmotorsports.com. I bet they would make one and you have your broken stock one you could send them if they needed it.

#5

Here are the pics. It looks like it sheared on the hard plastic like material.
No pulleys or accesories are seized or feel slightly odd when I turn them by hand.


http://i17.photobucket.com/albums/b89/DirkieUys/IMAG2637_zpstws7w7xw.jpg


http://i17.photobucket.com/albums/b89/DirkieUys/IMAG2631_zpsnuotse4l.jpg


http://i17.photobucket.com/albums/b89/DirkieUys/IMAG2636_zpsfacbvjxr.jpg


http://i17.photobucket.com/albums/b89/DirkieUys/IMAG2630_zpsndapsndb.jpg


http://i17.photobucket.com/albums/b89/DirkieUys/IMAG2635_zpsfh6ocx5b.jpg

#6

Wow that was bad. Thanks for the pix it really shows how bad it was

#7

agree, guess this is another weak part on the 3.0t. Hopefully an aftermarket solution will come out, im up there in mileage also, so i maybe on this list soon.

#8

also here is reference to the other same failure.
http://www.audizine.com/forum/showthread.php/627126-Much-power-such-throttle-dead-pulley

#9

It looks like the pulley is a 2-piece completely isolated design and the rubber just sheared leaving the outer rings freewheeling.

Kinda sad it only last a few years and 104km but it looks like you got it under control. Good work!

On the BMW N54s they didn’t really have a bad crank pulley (I think it was from weak belt tensioner) AFAIK but there were a few people that literally blew engines because the serp belt frayed and somehow got wrapped around the crank snout. It got sucked into the crank front seal, destroyed it and got into the engine and blew it.

The n54 belt problem is pretty unusual IME but it may be worth doing a close check of the crank snout if possible, to make sure nothing got in there.

#10

Was this an OE belt, or a replacement belt that came with your aftermarket pulley?

#11

I used a new OE belt. It’s done roughly 38 000 kms with it on.

#12

Good to know.
Yes, the crank pulley is comprised of multiple components, separated by a rubber isolator.
Per the audi 3.0 TFSI manual, it’s there for damping the load sent to the SC. I guess swapping the pulley is a good prev maint item–esp for those cars that are driven hard!

#13

Well i think this happened to me this morning. I wont know for sure till i get home, but it sure seems like this. I pulled out of my driveway this morning for work and my power steering felt glitchy.

Started to drive down the street and i could smell a rubber smell, thought my tires were rubbing. My battery light came on blinking. I pulled back home, the p3 gauge was only getting 11-12v.

I popped the hood, the belts are all intact and were spinning, so i will see when i get home what the verdict is. I’m thinking either the alternator seized or the pulley is shot. Definitely the rubber smell was coming from the front of the car. Took my other car to work instead.

#14

I got all the belts, tensioners , pulley guides + flywheel pulley and got a Audi machy to help me install the parts. He discovered that the Alternator pulley has got a clutch function, and this has seized. The pulley is supposed to grip going in the one direction, and slip in the other. Getting that tomoz. Hopefully car will be good in the evening.

So far parts are just on 650 USD.

#15

Curious on the alt pulley, if you could take a vid of how the new one works. Mine seems to be like a normal one, it doesn’t have a one way bearing unless it’s shot like you say. I don’t see why a 1 way clutch pulley would be needed, never heard of that for an alt.

Yea my crank pulley failed the same exact way, add another to the list. 95k miles

#16

^^ since i cant edit posts yet.

Ok, i guess i was testing my pulley wrong, you have to stop the shaft from spinning in-order to test it. If you just try and spin freely it will act as if the 1 way operation is not functioning since the alt is pretty smooth in turning. I will need to hold the shaft then test. Hopefully that is what you did to determine if it was bad and not just free spin it like i did.

#17

Got the car sorted 2 hrs ago, only read the post now. If you hold the new pulley in your hand and grip it by the center and turn the outer, you can feel it slips in one direction. It’s not quite free spinning, its has a dampening feel to it. The other way around it is solid. Old pulley is solid both ways.
It must have gripped and gradually worn down the main belt and Crank Pulley.
Car is running strong again.

#18

Pic of the culprit.


http://i17.photobucket.com/albums/b89/DirkieUys/IMAG2730_zpsgxgj1esm.jpg

#19

I checked my alt pulley and its operating just fine. I wouldn’t blame the alt pulley killing the crank pulley at this point.

#20

How/why is the pulley splined and threaded?