When using the heater, the noise of the fan is louder than it ought to be. Would consider a fix/swap to eliminate the noise.

Anyone ever fixed (or replaced) a noisy fan unit in the CX-5? Suggestions, caveats, guidance?


Details -- Has a pronounced clicking and noisier "whirrrr" sounds coming mostly from the right-hand vent on the front of the dash. Still works, and blows strongly. But it's noisy. Haven't been under the dash or digging around behind the engine at the firewall, yet, in the CX-5. But, so far as I can tell, the heater assembly has the air driven by the heater blower. Looks like it's accessible from the passenger area beneath the dash and glovebox.

Looks reasonably straightforward. Uncertain, yet, if there are other supporting fans, but it looks like everything's driven from this main "heater blower" assembly.


According to the write-up and diagrams at MCX5.org:

Steps:
Mazda CX-5 Service & Repair Manual - Blower Unit Disassembly/Assembly - General
Mazda CX-5 Service & Repair Manual - Blower Unit Removal/Installation - General

Mazda CX-5 Service & Repair Manual: Blower Unit Removal/Installation
Mazda CX-5 Service & Repair Manual / HVAC / General / Blower Unit Removal/Installation

1. Disconnect the negative battery cable..
2. Remove the following parts:
a. Front scuff plate (passenger-side).
b. Front side trim (passenger-side).
c. Dashboard under cover.
d. Glove compartment.
e. Decoration panel.
f. Lower panel (passenger-side).
3. Disconnect the blower motor connector.
4. Disconnect the air intake actuator connector.
5. Remove the blower unit installation nuts.
6. Pass the blower unit projection between the brackets shown in the figure (1) and rotate the blower unit (2).
7. Pull out the blower unit in the direction of the arrow (3).
8. Remove the blower unit.
9. Install in the reverse order of removal.

Diagrams:

http://www.mcx5.org/images/books/157...uw00001163.gif

http://www.mcx5.org/images/books/157...uw00001164.gif

 

Have you tried running the fan with the engine off? If not, try that at the various fan speeds, and see if any new information shows up. And if the same noise is still present, find out if anything is inside of the fan cylinder. Although it doesn't seem to make sense that critters would make a nest inside the fan cylinder, I can confirm for certain that they do. And if not a rodent nest, then I'm sure it's possible for other debris to accumulate inside the cylinder as well.

 

Yes, it's the fan ... with or without the engine running.

Haven't yet gotten into the dash to remove the blower assembly. But I get the point. If there's an ingress path for little critters and debris, it wouldn't surprise me in the least to find that in there, or in the nearby ducts. I'll check for all of this.


Just wanted to check with people who've done this sort of thing previously, to know if there are any caveats or tips for rooting around in there where the heater blower is. Looks straightforward, but you never know.

 

I'd expect that the plastic panel below the glove box on your vehicle is a very easy pop-out, just like the one on my 2020 is. If so, why not just remove that panel, and check the blower unit, before thinking about removing anything else. You can put your hand on the blower motor and case while the fan is running (vehicle off), and you should be able to determine if the noise is coming from that unit or not. But if it's still not completely clear via touch, you can either use a mechanic's stethoscope or a piece of wood to listen to the unit and surrounding components to try confirming that something in the blower assembly is the source of the noise (or is not). No sense IMO to disassemble anything, unless you have to.

 

Haven't yet dug under there, yet. But, as you say, if it's a simple pop-open of a panel or two, removal of a simple part or two ... that's definitely worth trying first. Don't have a stethoscope, but I've got a buddy that does much of his own vehicle maintenance and I'm sure he'd part with it for an afternoon.

The noise certainly sounds electro-mechanical, and not simply something died-and-dried in there that's swirling around. I'm betting it's the motor or fan itself that's either going or dragging, or something. But, I'll soon find out. It's not bad enough to completely replace, yet, but it's annoying. Hopefully it's something simple.

 

Replacing your blower motor
It is a 15 minute job with common DIY garage tools.

But even if you don't replace it removing it allows for a better inspection and a look inside to see if there is any obstructions.
If your going to replace the blower motors there are better aftermarket quality units then OEM MAZDA!
Oh and as long as you may be going this far you may as well consider doing a HVAC servicing of the vents . VERY VERY VERY easy to do and well worth while.


BTW you can make your own trouble shooting hearing device with a Philip driver a flathead screw and about 12-18 inches of vacuum line.

 

Am unfamiliar with the quality, reliability and relative silence of other competing makers' models. Any suggestions for an improved unit, if it comes to replacement?

CarID lists a few, for example (=2.5L]click):

• Mazda OE KD4561B10 - HVAC Blower Motor Assembly -- Item # mpn4681675249 more details on - https://www.carid.com/mazda-oe/hvac-...kd4561b10.html
• TYC® - HVAC Blower Motor Assembly -- Item # mpn4479735551 more details on - https://www.carid.com/tyc/hvac-blowe...&url=100504339
• gpd® - HVAC Blower Motor -- Item # mpn4667475578 more details on - https://www.carid.com/gpd/hvac-blowe...&url=100504339
• UAC® - HVAC Blower Motor -- Item # mpn4774007988 more details on - https://www.carid.com/universal-air-...&url=100504339
• Four Seasons® - HVAC Blower Motor with Wheel -- Item # mpn1304625057 more details on - https://www.carid.com/four-seasons/h...&url=100504339
• TRQ® - HVAC Blower Motor and Wheel -- Item # mpn4818481466 more details on - https://www.carid.com/trq/hvac-blowe...&url=100504339

Uncertain what "HVAC servicing" of the vents entails. What, removal of each of the vent covers and swishing-out of the ducting to get them as clear as possible? I'm assuming there is a cheapie tool or two that people typically use for this sort of thing. Wouldn't surprise me there are bit of leaves and whatnot in some of the ducts; I would assume this is what such "servicing" is.

 

Check Amazon:
**DWD2 Clean Air 3 Stage A/C Mold Cleaning and deodorizing System Bundle - Refresh Your Air Conditioner!

IMHO having tried a couple (won't mention the brand) the Four Season has the best blower Morte on the market for a MAZDA. The flanged version which is what you are looking at is very quiet on low speeds and does carry more air volume at max speed.

Amazon has it a little less: This is also the part number the MAZDA 3 my year and your CX5 use many of the same exact HVAC parts.

Four Seasons 76983 Flanged Vented CCW Blower Motor w/Wheel

**Starting from post #261
HVAC servicing.
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