Author Topic: Heater Blower Fan Noise  (Read 7366 times)

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Offline zigzag

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Heater Blower Fan Noise
« on: March 29, 2013, 12:02:21 pm »
Over the past week I started to notice that the heater blower fan was making an annoying ticking noise. I was beginning to think the fan motor bearing were starting to fail and that I would need to make a trip down to the dealer to get it sorted out under warranty. However, similar noise problems had also been reported on various US Mazda forums and one suggestion was it could be dried up leaves stuck in the blower fan which is located behind the glovebox. So today I decided to do a little more investigation myself by removing the glovebox to get access to the pollen filter (I found a video on YouTube showing me how to do that :) ).  Once the pollen filter itself was out I could just about get my fingers into the gap to spin the fan motor blades by hand. No noise was evident when I did this and so it ruled out the possibility of the fan blades catching on something. The gap was too small to be able to feel any further into the recess. Therefore, as a last resort, I thought I would try vacuuming up any debris that might be trapped down there. But once gain the gap was too small and awkward for an ordinary vacuum hose. So instead, I adapted a length of narrow plastic tubing and stuck that onto the end of the vacuum hose. When I tried this and checked what had been sucked up, it was indeed a dried up leaf  :), and now, I have no more noise coming from the blower fan.

I thought I would share this in case anyone else runs into the same problem. I do find it surprising though that leaves can make it past the pollen fitter and get lodged in the fan like this.

Just one question, the pollen filter has arrows indicating the direction of the air flow. When I took mine out I forgot to make a note which way round it was meant to go. Is the direction of the air flow downwards or upwards?

Offline SM25T

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Re: Heater Blower Fan Noise
« Reply #1 on: March 30, 2013, 06:17:03 pm »
I think you will find that you get debris landing on the pollen filter in normal use.

When the filter is withdrawn, all the crap on top of it is scraped off and falls under it. Unless you vacuum this out, it will get sucked into the fan after the new filter is fitted.

There is your clue .... the dirty side of the filter faces upwards.