I drive a 2001 Chrysler Town & Country.
For the past several months I have noticed this rumbling kind of noise coming from the back of the van when I get over 25 mph. It sounds like a rumbling/roaring noise. It’s rhythmic like a “woo-woo-woo.” The fast I go the faster the woo-woo-woo goes and the higher in pitch it gets, but it’s still a low noise … it never becomes like a whistle or anything. Also, I am not sure if this is related or not but especially when I first start out driving the van and I press the brakes I hear this low kind of scraping/grinding noise … it doesn’t sound like metal on metal … it definitely has some “texture” to the noise. This noise is audible but not super loud. Does anyone have some thoughts? Are these dangerous issues that need to be addressed immediately? I usually have two kids in tow and want to make sure that we all are safe.
By your description you could have wheel bearing problems and brake problems. Take off the rear wheels and look at the brakes. Check for smoothness and free play on the rear hubs.
Any brake noise that is not usual should be checked out. A bad wheel bearing can lock up a wheel and cause a skid. Yes, you could have a safety problem.
I agree wholeheartedly with Beads that you should get your brakes checked for that scraping noise.
While you’r there have them check your tires. That rhythmic “woo-woo-woo” is typical of tires that are getting low on tread.
Both of these are potentially dangerous. You should tend to them both immediately.
I have found many lumpy/bulging tires simply by running my hands around them (also cut myself on wire) I would safely check your tires for defects.
Get a wheels off brake inspection (as others have noted)
I have delayed tire rotation on a front wheel drive vehicle more than once. It usually results in odd wear patterns on the rear tires that eventually make noise. I often hear this noise coming from other cars too while walking next to a road. I have also observed tire noise after rotation when there was none before.
If you have not rotated your tires per the advice in the owner’s manual, this could be the cause of the noise that you describe.
The odd wear patterns such as flat spotting or scalloping that I mention are quite visible if you closely inspect the edges of the tire treads.
If it is your tires and not the wheel bearings, the noise is harmless regarding safety but annoying.
With narrow tires, the noise can go away after a few thousand miles after tires are rotated but there are few or no narrow tires having an 80 series aspect ratio these days. With wide tires, the noise may never go away after rotation.