04 Maz3 noisey hvac blower fan ?

[uxhamby]

My daughter's '04 Maz3 came home with an odd issue today.

Apparently, the hvac blower fan abruptly started making a rubbing noise, which gets louder the faster the fan is run. Its quite loud and vibrates the whole dash.

I was thinking that perhaps some leaves or other debris had got into the works, so I dismantled the passenger side trim & duct work to inspect the cabin air filter(s). I found no filter but got quite a few leaves etc out of the heat exchange plenum. Despite the clean up, the noise persisted.

Next I got a small mirror and a flashlight and looked up into the filter opening and watched the fan cage spinning. I didn't see any debris up there but I noticed that if I pulsed the fan switch to just rotate the fan cage slowly, I could see that its not spinning evenly on its axis of rotation. My theory is that the wobble, visible at slow speed, worsens at high speed causing it to rub against something and the noise.

I'm quite willing to do a replacement of the fan but since quite a lot of dismantling is called for, I thought I'd do a bit of research first. Not to mention, get in some spare parts etc.

So, does the Maz3 have any general history of this I should know about? Is anything LESS than a complete fan replacement called for?

Thanks,

Brian H.

[uxhamby]

Further to this, I replaced the fan and blower with one purchased from a wreckers. When I installed it, I checked very carefully that its rotation was nice and symmetrical around its axis of rotation i. e. no wobble. It lasted about a week and the rubbing noise came back.

Have just dismantled the whole thing again to find that the blower cag is AGAIN wobbling on its axis. Im somewhat perplexed and would like to know if this is a common affliction with these cars?

I have destructively disassembled the blower cage from the original motor shaft and it looks to me as if the heat from the motor is conducted down the shaft and melts the plastic fan cage hub enough for it to distort.

I ran the original fan motor in free air for about 10 minutes but it didnt get hotter than I could hold onto.

Suggestions / experiences would be welcome. Thanks.

[uxhamby]

The blower motor housing, has a 1/2" dia port and hose on the back side that is listed on documents I've turned up online as a "motor cooling air inlet". I have mine connected at the motor end, but wonder if it has come adrift at its other end, and thus isn't supplying the cooling air properly. I can't see or feel where the hose comes from and alas I dont have a manual on this car.

Can anyone shed any light on the fan motor cooling air source for me?

Thanks,

Brian H.