# 2007 Mazda CX-9 hums **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [August 16, 2023, 4:22pm UTC](https://community.cartalk.com/t/2007-mazda-cx-9-hums/192317 "2023-08-16T16:22:38Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Cdc](https://avatars.discourse-cdn.com/v4/letter/c/b2d939/32.png) [@Cdc](https://community.cartalk.com/u/Cdc)\ **Post date:** [August 16, 2023, 4:22pm UTC](https://community.cartalk.com/t/2007-mazda-cx-9-hums/192317/1 "2023-08-16T16:22:39Z")
I am hearing like a humming noise when I speed up it grows with the speed. ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [August 16, 2023, 9:33pm UTC](https://community.cartalk.com/t/2007-mazda-cx-9-hums/192317/2 "2023-08-16T21:33:11Z")
It might be the normal fuel injector sound. Seems possible it has been there all along, but so faint you didn’t notice. Until one day you did notice, & now you are hearing it consistently b/c only now you listening for it. ---
**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\ **Post date:** [August 23, 2023, 12:57pm UTC](https://community.cartalk.com/t/2007-mazda-cx-9-hums/192317/3 "2023-08-23T12:57:14Z")
If the hum is a lower pitch, failing wheel bearings are a possibility. ---
**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\ **Post date:** [August 23, 2023, 3:12pm UTC](https://community.cartalk.com/t/2007-mazda-cx-9-hums/192317/4 "2023-08-23T15:12:39Z")
> [@Mustangman](#): > > failing wheel bearings are a possibility. +1 Or, this could be tire-related. Are the OP’s tires nearing time for replacement, or were they recently replaced with a type of tire other than the previous tires?