I have a 2008 Subaru Impreza that makes a weird, low humming noise and slight vibration, but only when driving between 30 and 35 mph. The problem occurs whether I’m depressing the gas or not, and even occurs if I shift into neutral or even turn off the card and coast. At speeds over 40 it goes away completely.
My local mechanic gave it a look and said he didn’t find anything, and that the issue might just be a loose (or poorly manufactured) dashboard that has a resonating frequency around those speeds… but I’m not sure I believe.
Any thoughts on what I should get checked out? Anyone else with Subaru’s experience this phenomenon?
Did he go for a test drive? Find another mechanic if he didn’t.
If it gets louder when curving one way or another, it could be front wheel bearing.
He did. He’s actually the one who noticed that the noise persists even when coasting with the engine off. I’ve used him for a few years and so far he hasn’t steered me wrong… I just feel like he’s missing something here.
I haven’t tested if it gets worse while turning at that speed, but I’ll give it a go and look into CV joints.
Thanks for the suggestion.
Check your tire wear pattern to see if they are exhibiting any feathering, cupping or other problematic wear issues.
Tires are still pretty new and look good. No wear patterns I can identify.
Turning or driving into a curve doesn’t seem to affect the noise for better or worse. It still seems to just be the speed.
I checked out some CV joint and bearing issues and my noise doesn’t seem to match. I took a quick video that kind shows what the hum is like: https://youtu.be/_CHXGSh-4hk.
You can hear the buzz fade away as I drop into about 25 mph.
Just wanted to give an update.
Put on new tires and had them balanced. Checked breaks. No change. Still getting the resonance.
One thing I did notice as spring where I live fluctuates between 80 and 40 degrees. The colder it is, the more persistent the vibration. The hotter it is, the harder it is to detect and I have to get to higher speeds, around 40 to locate it. Not sure if that helps narrow down the issue.
If I ever figure it out, I’ll be sure to post.