Ok, I'll also send the video to the local German mechanic and get his opinion. What do you think about the transmission?

 

I don't think anything of the transmission, if it shifts fine its ok. That service light has ABSOLUTELY NOTHING TO DO WITH IT. I suggest you find an owners manual and read it cover to cover.

 

I wasn't referring to the light, I previously said that I wouldn't worry about it unless it was constant... I was talking about the vacuum-like sound when shifting into reverse...

 

You won't get a sound like that from the trans, it would come from the engine. There is a vacuum pump (on automatic models) thats next to the engine which will activate in reverse, however you shouldn't be able to hear it. It could be getting on in life, but i have never had to replace one so don't worry about it too much. The vacuum pump is just to help the engine produce engine vacuum with load on the engine, its way overdesigned.

 

Ok. Are the belt tensioner and fan clutch DIY jobs? My father and I are fairly handy. However, I'd like to add that I drove the car for about an hour and a half at speeds of 80+ MPH, with several enjoyable bursts of acceleration, and the coolant indicator was at less than half the whole time. Granted, this was in 30 F weather, but I thought I would add that bit of information. What causes the fan clutch to fail, and how could I know for sure?

Also, it doesn't look like there is much play in the belt...

Also, you are referring to the accessory belt tensioner and not the timing belt tensioner, right? Just want to make sure.

Thanks again, you're definitely the man when it comes to Audi concerns online.

 

Well the fan clutches just wear out after 100k or so, it sounds too loud for it to be one of the timing belt pulleys or water pump. However i would still check it because that belt/water pump should be changed every 80k, do you know the history and what was replaced and when? Pop one of the timing belt covers off so you can grip the belt, if you can't twist it more than 90 degrees its fine. Its still probably something on the accessory belt making the noise, thats what it sounds like to me.
What do you mean the coolant indicator is at half? You mean on the coolant resivior or the coolant warning lamp came on?

 

Oh, and yes you can easilly change the fan clutch, you just need the tool to spin the nut off counter clockwise.

 

No, the engine coolant temperature gauge stayed at less than half. I don't know the exact history, the seller said it was replaced, but I'm not sure if I believe that since he obviously lied about the current condition of the car.

While the fan clutch should be changed as preventative maintenance, is it what's making the noise? I know that it's probably hard to tell from the video, I'll probably get the oil changed and let them check it out. From my understanding, if the tensioner is bad, the belt would have play in it, right? Also, why does the noise go away after the engine has been running for a few minutes?

I think I'll go spray some water on the belt to confirm that it is indeed coming from it.

 

Oh, well thats normal, its supposed to be right in the center.
The fan clutch isn't whats causing the noise, i just noted that since its toast the previous owner obviously didn't keep it up to date as he claims, which leads me to believe the accessory belt tensioner has never been replaced either which is most likely the cause. I would put the front end in service mode http://audi-diy.blogspot.com/2007/11...d-removal.html same as here but you don't need to remove the coolant lines, just disconnect it and pull it forwards to gain better access at the belts, now you can run the engine and spray each pulley with WD-40 or silicone spray to see if one of them shuts up when sprayed. I would think the serpintine belt tensioner pulley is at fault because the bearing is exposed at the back of it where dirt can get in there.

 

I've actually determined the noise to be the fan on the front right of the engine. With the car off, we span if a few times by hand and the sound is audible if you spin it fast enough... what is this fan's official name, and how would I go about replacing it?

Out of curiosity, what would valvetrain noise sound like in this car, and would there be codes/CEL?