ok i made a post earlier today about my fuse for the secondary fan keeps blowing and when i put a fuse in, the car started making a horrible noise and shaking and stuff. well i bought another fuse today to troubleshoot and find out what was shaking so bad and i found that it is the secondary fan. as soon as i put in the fuse, the fan came on (i just got done driving home so the engine was pretty warm).the fuse didnt blow, but the horrible shaking noise was coming from my secondary fan. it was shakin like it was about to break off and fly away. it has never done this before. i turned the car off and checked to see if a mounting bolt had broken or something and all the mounting places seemed to be intact just fine. so does this violent shaking mean that my secondary fan is on its way out?? if it does go, i imagine that a cheap electric aftermarket fan would be much cheaper than getting an actual audi repacement fan and it would do the same thing (provided that it flows the same amount of air). has anybody ese had this issue? could it be anything else besides my sec fan thats about to break??

 

It sounds to me like part of the fan itself is broken or has something stuck on it. Disconnect the fuse before going near it and have a closer look at the blades and surround. Look for a crack if theres nothing obvious.

on the aftermarket fan I agree, if the amperage and CFM are close, but will defer to the experts.

 

yeah i already looked at the fan and didnt see anything wrong with its hanging mounts or zny cracks. i have the fuse taken out cause i cant stand feeling the vebrations inside the car or listening to the sound while i'm driving but its getting hot and i really need my AC so i need to get this fixed. i just dont know if buying a new fan will solve the problem...plus the fan spins freely like its supposed to right now so i dont even know if thats the problem at all.

 

Pull both Fan control relays in the aux relay panel
Fan should not run with key on.
Key off. Replace relays

Pull the coolant thermal switch connector located on the hose adaptor
at the bottom of the radiator. Key on. Fan should not run on hi.
If it does, the hi speed relay might be bad.

Thermal connector pinout looking into connector (towards harness)

Latch
2 4
1 3

Key on.

Looking into the connector face
bridge 1 & 2 to get stage 1 speed (low)

Bridge 1 & 3 to get stage 2 speed

Key off. Did stage 2 make you run for cover?

With the coolant thermal switch reconnected
and coolant temp under 80C (~ 175F)

Key On. If the fan goes back to takeoff speed, its most
likely the thermal switch.


The thing might still be a bit unbalanced
...not unlike more than a few of my friends... but only showing up
on hi....not unlike more than a few...........

 

Mecahnical problem with the fan. It needs to be replaced.

 

i found the problem. somehow one of the blades broke off completly. i have no idea how that could happen while driving, but it did. and so that threw off the balance of the fan causing it to vibrate. it looks like there is just a bolt holding the plastic blades on to the motor itself, so does anybody know if you can replace just the plastic blades or can you only replace the whole fan assembly

 

ECS has whole assemblies motor and all for like $150. I saw OEM blades at some race shops for $50 but they listed them as belt driven even tho they looked the same as the electric. Junkyard or better .. classifieds here.

 

double post. deleted.