So I started hearing a new noise this week and need some ideas.
It varies with speed but not RPM. Turning doesn't change it. Handling and ride still feel normal (no slop or wandering).
Under 30mph, I don't really notice it.
At 30-60mph, it just sounds like tire noise that you'd get from an offroad tire. I have street tires and this noise is different. Radio at normal volume is usually enough to drown it out.
Over 60 mph, start hearing it more and at 65mph it sounds like I'm following one of those crappy riced out Hondas and there is slight vibration in the floor. A buzz or hum might be the best description. It continues like this up to 70mph. I haven't gone over 70mph.
I can't figure out where exactly the noise if coming from since it's only at speed.
Things I've changed recently before the noise:
1. New brake pads but noise didn't start until about 1200 miles after installing them.
2. Drain/fill rear diff. Used same oil as last time. Did this about 2 weeks (~800 miles) before the noise started.
3. New rear engine mount (at tail of transmission). OEM part from dealer. Installed about a week (~400 miles) before noise started.
4. Greased u-joints about 1 month (~1600 miles) before noise.
Things I've tried to see if the sound changes or to see if anything feels odd:
1. Changing lanes or taking long curves at speed. Didn't change the sound at all.
2. Shifting into N (auto trans). No change in sound.
3. Slow figure 8s in a parking lot. Didn't feel any slop in the steering or hear any popping sounds.
4. Driving around the yard and in the woods to flex the suspension. Didn't hear anything odd.
5. Greased u-joints again. No change in sound.
6. Checked tire pressure. 32 psi all around as usual.
7. Braking hard from ~60mph. Feels normal. No vibration or anything.
8. Accellerating lightly vs aggressively from 40-70mph. Hear it more under light accel but that's only because I can't really hear it over my exhaust.
9. Taking foot off gas at 70mph and coasting down to 30mph. Same as usual (loud buzz until I get around 60mph, then seems like road noise that gets quieter as I slow down).
10. Driving 65mph in overdrive or regular. No difference.
Anyone have thoughts?