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Excessive blower motor noise

20K views 15 replies 12 participants last post by  VAFury 
#1 · (Edited)
Does anyone else consider their blower motors excessively loud? Mine isn't broken. or worn out and squealing, it is just plain loud. The volume of it running at high is not proportionate to the amount of air it is moving. I’d like to know if anyone else has noticed it or done anything to quiet it down. Maybe some insulation or perhaps a non OEM blower or new squirrel cage or something like that? In my other vehicles you can’t hear the blower motor at all you just feel the air and I'd like to get my Volvo like this.
 
#4 ·
Mine is not loud, all you hear is moving air.
Remove the cabin air filter and check if contaminated. A blocked cabin air filter might make the motor work harder.
Ensure no leaves or debris exist in any of the vents, including the intake vents in front of the windscreen.
And if an interior vent is closed to just the right angle, it can cause a slight whistling noise as the air moves past it.
 
#5 · (Edited)
I have replaced the cabin air filter with two different ones. I do get a weird moldy or stale smell sometimes and I think it is something in my fresh air vent system. I have used cleaner to rinse the vents under the cowl with the hood up several times trying to flush the source of the odd smell away. I have used purple power degreaser.. rubbing alcohol and bathroom cleaner, next I will try bleach. It isn't very strong.. and dissapates once the A/C and fan run for a minute or two.
The blower motor is not hitting or rubbing anything that I can tell but it is very loud. You can physically hear a vroooooom sound as it set to anything other than the lowest two settings. On high, you can actually hear it outside of the car a pretty good distance away over the engine noise and feel the RPM's of the fan motor resonating off the plastic peices in the car.. There is no clunking it is a constant even pitched, low mechanical soudning noise. Almost as if I am hearing a resonating vibration.. that is very loud. I wonder if my squirell cage is unbalanced. I am not sure if there is a way to balance it or not. It works fine.. no problems at all other than loud as heck.
 
#6 ·
I keep reading this post, trying to figure out if it's an issue or not.

Easiest way to find out is to turn the fan down to zero, then turn back up in single clicks, listening to the fan come up in increments of speed. I tried this a second ago, you can hear the fan increase speed in steps as you turn in single clicks up and down.

If you hear steps of increase, it's likely that the fan and fan controller are working properly. If the fan goes from off then low then full blast in the first couple clicks, something is not right, maybe controller at fault.

One slight possibility, if it's working properly, is to disconnect the battery (wait 5 mins after car is turned off before disconnecting), let it sit for a half hour or so then reconnect (key in POS II), followed by doing a "calibration" of the fan speed as noted below-
If the car is equipped with Manual Climate Control (MCC) or Standard climate control system, fan speed must be recalibrated if the battery has been disconnected.
Ignition on. Turn the fan control to max. Turn the fan control to min. The calibration is complete.


If in the end you have a working fan (steps properly in speed when fan knob is turned) but it's simply noisy, consider replacement of the fan unit itself. Couple posts in the XC90 forum from folks who have done it (me included, mine was squeaking), relatively easy job.

Decent description here on how the climate system as a whole works- https://forums.swedespeed.com/showt...2007-XC90-V8&p=5657961&viewfull=1#post5657961, vehicle noted in the PDF is S40 but they're all pretty much the same.

Good luck in your repair!
 
#10 ·
I fixed the excessive blower motor noise



Your video was helpful. My 2013 was doing the same thing. I read all kinds of cures but removing an breaking one of the tabs to the motor. Got a quote from the Dealership for $1800. I just lived with it for a while keeping the fan under setting 3-4 until I could figure this out. I read somewhere that it may be possible to go from the top to get into the blower fan so I followed this link video to remove the wiper arm and the Cowell under them )https://xemodex.com/us/knowledgebase/central-electronic-module-removal-2/) It is for access to something different but it got me into the blower compartment. I only took off the passenger's wiper are as the Cowell was loose enough to move out of the way to access the blower compartment. I also need a small puller to remove the wiper arm. Once in the blower compartment, there is a shroud/cover that blocks direct access which slide out easily. I was able to see directly into the blower fan cage and saw 1 1/2" piece of foam. It does not take much to through out the balance. I used a grasping tool, but a small hand could get down in pull it out. If I can post pictures of it I will. I hope this is helpful to others. It was an easy fix and was thankful it was a warmer day to work on it. It took about 2 hours. I suspect when I had my windshield replace (2 times because the put the wrong one in) a piece of the foam must have been floating around until it finally fell in the blower fan.
 
#9 ·
That sounds like something is vibrating badly at a low frequency. I'd guess a balancing weight came off, dead mouse stuck in the squirrel cage, etc.
Mine you can only hear the air rushing out of the vents.
 
#13 ·
That sounds like something is vibrating badly at a low frequency. I'd guess a balancing weight came off, dead mouse stuck in the squirrel cage, etc.
I'd wager this is the case. After a major front end wreck, we had our car rebuilt and once it was returned the fan noise was hideous. They found a wad of masking tape inside the squirrel cage. Checking for variable noise at different fan speeds is a good suggestion as an imbalance is often accentuated at different speeds.
 
#12 ·
XC70. fan noise

2008 XC70 Sits a lot since the owner is away. Loud noise developed when heat was turned on at the beginning of the fall. Pulled cabin filter which was dirty and noticed a small amount of mouse nest type material.
I tried vacuuming one of the vent intakes under hood without success . The removed wipers and plastic cowling below the windshield. Reached into the intake and found large amounts of mouse nest material. Removed it all and tried fan again which now worked great without that horrible noise.
Added a 1/4 inch hardware screen over the intake before reinstalling cowling and wipers.

2009 XC70 Last year had horrible clunky noise when using fan. Sound changed depending on fast slow setting. Was able to lessen the noise 80% by adjusting the speed up and down till it was tolerable but not totally gone.
After fixing the 2008 (above) I revisited the fan intake on the 2009 xXC70. Found a single hollowed acorn. Once removed fan was 100% perfect. I added the same 1/4 hardware screen to the 2009 prior to reassembly.

Moral of stories
Don't let mice infiltrate your Volvo. Don't let the Volvo sit too long.

Anyone know a good auto mouse deterrent?
 
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