Near the beginning of December I had winter tires/rims installed on my '11 Journey. A few weeks ago, I began to notice a noise coming from somewhere when cruising around 60-70 km/h. I've since narrowed it down to when the transmission shifts into 5th gear and I am cruising at around 60 km/h, it makes this sound only when I am on the gas (for example, going up a mild incline and using enough throttle to maintain speed). It sounds like a low rumbling/rubbing/grinding sort of sound. I have no unusual sensations or vibrations coming through in the steering wheel or the throttle. If I had to compare the sound to something, it's sort of like when you're driving a standard and you try to accelerate hard in too low of a gear.
I have no idea if the sound is somehow related to the winter wheels. I have inspected the wheels and they are not rubbing the calipers, and I also had the tire shop check that there were no rubs. My stock wheels are the 19" rims, however I purchased 17" steel rims and tires for the winter set (simply due to cost of the larger 19's).
I did some testing and experimenting this evening using the autostick to control shifts. The sound starts in 5th gear around 60 km/h, however it subsides and seems to disappear when speed increases passed 70 km/h. Around 80 km/h, if I shift into 6th, it starts that same noise again. Again, only when being loaded (quiet when coasting). Gears 1-4 do not appear to generate any noise.
I'm not sure if this is a case of the transmission being confused by the lower diameter tires and being in too low of a gear during cruising or if there is something actually wrong with the powertrain somewhere. There seems to be no other symptoms than this noise, and I am positive the noise was not there before.
Anyone have any input on this?