ThaboTheWuff

I came after a long 500 mile road trip to the sounds of grinding metal towards the front of the car. I diagnosed it as the viscous fan bearing but upon removal of the fan I still hear the noise So it has to be the bearing that is in the pulley.

My mechanic tells me that it's an entire unit, fan support bracket that contains the bearing and is failure is very rare so I'll have to get the part from the dealer perhaps??

Can anyone tell me how to remove this part, worried that it's somehow connected near where the timing belt sits and I'll have to remove this too. The fan is off, gotta figure out how to remove the serpentine belt and then remove the 3 10mm bolts on the fan pulley head and then ???????

Any suggestions on an after market part or trying to replace just the bearing. The car is work $4k tops and I hope that this small expensive part is not gonna be her downfall.

Update: Just called local Audi dealer and it's call the flange shaft and is $430 - part number 077121211.

audinutt

Use this part # 077115136a.
It's the bearing alone. should be around $100

You will need to press the old shaft out and press it back into the new bearing.

ThaboTheWuff

Excellent, I give it a try once I get the bugger off the car. Will need to fine a machine shop that can help me out I guess.

audinutt

Or a vise and hammer/punch.

Adjuster

Can the fan be removed, and just go with a good electric fan?

Wire it up to a relay, use the signal to the existing fan as the switch for the relay, and there you go.

Fan comes on when the seperate fan is called for, should keep the car from overheating just fine, and a large aftermarket fan is under 200.00 with a relay etc.

Will result in better fuel economy too.

ThaboTheWuff

Fan is out and if fine but pulley is where the bad bearing is and the pulley can't be removed. COuld drive around with bad bearing but very soon she'll explode and perhaps Mr Fan pulley will end up in my 2 front radiators - $$$$$$. This biatch will have to come out and as I said before there is very little room work. I am going to have to use a mirror to find the place where I need to stick in a drill bit.

silverd2

Doesn't work that way and would take a lot more than that to work properly.

The existing fan mainly runs for the AC refrigerant, and without climate control on, only runs when temp goes well above normal running temp...a back up for other failures or extreme climates.

The existing electric fan also is powered by a dedicated high voltage resister pack (expensive part) that could not run 2 fans.

A simple signal for the other fan (wrong criteria) and relay would not come close to maintaining a constant coolant temp, which is essential for consistent fuel mixture and mpg's.

Nothing is free...major electrical draws in cars, rob the engine of some power. Ever notice how just turning on the rear window defrost (major draw) drops the idle a bit.

The viscous clutch fan is a simple, efficient & uncomplicated system that robs next to no power from the motor...nowhere near as much as an AC compressor, or even a power steering pump. Completely mechanical (always a plus), it pulls in more air thermostatically as engine heats up. Added electric fans in newer cars add complication (more systems to fail)...more electronics to regulate and more electric power draw.

silverd2

A simple mechanic's mirror (swiveling, on telescoping extension) and a little flashlight are my most used tools...both cheap...and cut down immensely on disassembly. They get easier to use with practice.

ThaboTheWuff

Yes, excellent idea. Thanks for all the help here in this thread guys - I've not worked on a car in ages and now it's time to get back in the saddle. My 4000 with the 1.8 4 cyl was the last car I think I worked on.

Adjuster

It's just my 1998 A8 was a belt driven fan with a fan clutch, and my 2004 A8L has only electric fans.

I also realize you can't just run two fans off the controller, thus, using only the fan power to trip the relay, and use at least a 30 amp relay, wired into a source of main power, with it's own seperate fuse and ground.

I agree that most mechanical fans do a great job, but if the bearing is xx.xx dollars to replace, and a large electric fan, relay and fuse is less, why not try the DC fan? (I know of a kit that is sold with two fan sizes available using this same setup for the most part.)

I would only consider hooking up to a fan that is not dependent on the AC system to get a signal to work.

On cold days, my current ride does not run the DC fans much at all, but on hot days, it sounds like a 737 on take off at times, and the "wind down" noise after shutting of the engine is classic large fans spooling down.

A big advantage is at speed, the DC fans are not needed for 99% of the time, so you are not dealing with the drag on the engine, or the alternator.

I would only consider this if the bearing was not needed however. If you need the bearing there for the fan, just to have the belt turn a now empty pully, it defeats the purpose too.

Just thinking outloud here, and I have seen some aplications where DC fans do not work nearly as well as the OEM fan/clutch setup.