'01 A6 2.7T: Help identifying an engine part please.
 

Hello,
So with the help of a mechanic friend, I have identified the part that causes my car to make strange whirring sounds (especially loud when turning the wheel).
When I open the hood, I look down and the part is this silver metal pulley-like thing. It is about the size of my hand and is mounted vertically. It is located directly behind the grill and does not need the plastic engine top cover to be removed to see it.
Any ideas as to what this is? Remember, it makes a loudish noise on startup and it gets worse when I turn the wheel. I will need to order the part and have a local Audi mechanic here replace it for me.
Thanks a lot for your help. I am new to this whole DIY thing and I am very excited to get deeper into it with your help on this great forum.

-Sam

Can you take a pic of it ?

I don't see anything like that on my '01 2.7 - I'm probably not looking in the right place...

Sounds like power steering pump noise, possibly low fluid, by what you are describing. Check P/S fluid level and suction-side clamps as a first course of action. Fluid should be Pentosin CHF 11S available at foreign auto parts stores.

Diagnose, then replace. Search this forum for "power steering noise".

Great advice. Thanks.
I will search around the forum and web for more information to make sure it is the part I am referring to.

Thanks again!

After looking at photos of the power steering pump, I have learned that this is not where the sound of coming from.
The part that is making the noise is more of a metal belt wheel/pulley. I will take a photo of it and post it here when I can.
Thanks.

The only "round metal belt wheel/pully"-like things I can imagine where you described are the accessory (serpentine) drive components and the various fans (which appear round and metal-like :) )

I'm guessing viscous fan clutch.

I'd pull the serp belt off and verify that the noise is gone. If not, it's timing belt related and needs to be addressed immediately. This is a concern, given the that the location you think it is coming from is right by the idler roller for the timing belt, the most common failure point.

If the noise is gone with the serp belt off, spin each component by hand to determine the source.

Save a few bucks by inspecting the PS fluid first...seems like it's the most-often overlooked wear item on a vehicle. If it smells burnt, replace it, doesn't take much. That will not solve any issue with the pump itself, but it will prolong the life of a pump on its last legs.

If that wasn't the issue, D4D's suggestion becomes critical.

Be wary of trying to locate a noise on a running engine, the apparent source can be misleading. What you are describing does sound like classic power steering system issues, so the last thing you want to do is replace major components based on where you think the noise might be coming from.

A general rule of thumb for keeping your power steering system in good shape...try to avoid turning the wheels in place.

Here are a couple articles from Google...none of them discuss what happens as the fluid ages, but they're good starting points.

http://cars.cartalk.com/content/advi...rsteering.html
http://www.hondaclub.com/forum/artic...ng-system.html
http://autorepair.about.com/od/regul...eer_fld_ck.htm

How do I go about checking the power steering fluid?

Check the owner's manual for exact location on your car...look for a reservoir with an icon of a steering wheel or similar molded/printed on the cap, pull the cap, insert rubber gloved finger, smell. Some cars have a sort of dipstick thing on the cap...means you don't have to dunk a finger in the stuff ;).

If it's really dark, or smells burnt, replace it. Search through the forums here, there are explanations for a DIY, and pictures. It's one of the easier fluid changes on the car.

Just be 100% certain you are using compatible fluid. The seals are not compatible with ATF...you can find that statement reiterated on the forums here (search), and by calling pretty much any service shop (I did).