Kneale Brownson

We've had some -20s (F) weather and today I discovered all the blades gone off the A6/S4 fan!! Maybe the Fleabay seller is wrong that his are OEM quality.

I've since replaced the failing Westportparts pos fan blade with one I got from AutohausAZ for just a few bucks more that looks a lot more like an OEM part should. The first A6/S4 blades just looked like seconds. The seller has been unresponsive to my efforts to take advantage of his advertised warranty.


I replaced the cracking AR fan today with the S4/A6 viscous clutch and fan.

Needed these:


<img src="http://www.pbase.com/kneale_brownson/image/144295962.jpg>


That's a 32mm wrench, 7mm socket and and adjustable pin wrench.

The OEM fan:


<img src="http://www.pbase.com/kneale_brownson/image/143309528.jpg">



There were cracks all around the fan. I think seven of the eleven holes had cracking going on.


<img src="http://www.pbase.com/kneale_brownson/image/144295886.jpg">


Fan is out:


<img src="http://www.pbase.com/kneale_brownson/image/144295905.jpg"


S4/A6 viscous clutch and fan:


<img src="http://www.pbase.com/kneale_brownson/image/144295973.jpg">


New fan in place:


<img src="http://www.pbase.com/kneale_brownson/image/144295968.jpg">


Removing the driver side boost tube provides just enough room to get the tools in place to pull the old fan and clutch (holes in the front of the fan driver pulley accept the pin wrench pins), remembering that its lefty tighty, righty loosy, and the 32mm wrench (1 1/4" sae would work too) make removal fairly easy. The 7mm socket is for the hose clamps.

Only real snag for me was that the OEM fan has three bolts holding it to the viscous clutch and the S4/A6 assembly requires four. Luckily, since it's Sunday, I found a fourth in some of my 200q20v parts.

pierreb

nice. i'll be doing this next weekend on the boy's car.

awdjunkies

Good Job! Where did you get the new fan from?

Kneale Brownson

I bought the S4/A6 viscous clutch from fleabay. Numerous sellers there. Cost about $45. The S4/A6 fan won't fit the Allroad viscous clutch.

I bought the A4/S4/A6 fan for $18 plus shipping from Westport parts:
http://www.westportparts.com/078121301EFanWheel.htm

Zuffenhausen951

Is the S4 fan considerably louder? I feel louder means more air is brought past the radiator, no?

Kneale Brownson

It's noticeably louder when accelerating at low speeds, but not objectionable. My guess is the ring on the OEM fan blades concentrates the air flow more, while the open blades of the S4/A6 version dumps more air to the sides, making it a bit less efficient. I see no increase in coolant temperature when pushing it.

Zuffenhausen951

True, the open fan blades create more air buffeting. Plus, the larger volume blades appear to displace more airflow. Looks like this is also my next project. What is the estimated ETA with all the right tools?

Kneale Brownson

If, unlike me, you have nimble fingers for reinstalling the nut that fastens the air tube, it's a pretty easy task taking under an hour. Took me two because I had to hunt down the extra bolt.

Zuffenhausen951

What size is the hex bolt that attaches the fan blade to the clutch? Looks like a 5mm x 15mm. Does that sound about right?

EDIT: It's a 5mm M10 Allen bolt. I found one among my huge bicycle parts bin.

Kneale Brownson

Not sure because I matched up from my tiny supply of nuts and bolts. It may be the same size as the thread on the license plate anchors.