After driving around 30 minutes at high speed (>80 miles per hour) on the expressway, there is a humming noise heard during the last miles of the highway and on normal streets immediately after the highway, which disappears completely a few yards later. This issue started only since 2 weeks. It has around 163000 miles. It is a 2010 Mazda CX9 GT AWD.
Have no idea. Hard to tell without hearing it and or experiencing it. Here is a great article I wrote that might help you narrow it down. I did take the time to look and see if there were any Technical Service Bulletins out on the issue but none were found.
What others on the web think:
- If your Mazda CX-9 is making a high pitched noise or hum, it could be a sign of a bad wheel bearing. There are several different vehicular components that can make a squeal or hum. That’s why it is important to know the other warning signs of a bad bearing before just going in and replacing it.
- We recently bought the Pirelli Scorpion tires at 30,000 miles for my 2007 CX-9. Its been 4 months and probably 6000 miles and there is now a loud humming noise, which the dealer thinks is tire noise. Is anyone having problems with tire noise on these vehicles? I went back to the tire store and they put on a Goodyear Wrangler and still had noise.