2011 BMW 335i with 120,000 miles… All tires appear to be in perfect condition. All tires are run flats. This morning, it started making a sound that was clearly related to the rotating of the front driver’s side wheel. It happens above 65 MPH, and as soon as I slow down below 65 MPH it stops. It sounds and feels fine below that speed, and I don’t really “feel” anything abnormal through the steering wheel while the sound is going. It almost sounds like the tire has gone flat or is coming apart, but the tire is still full at 32 PSI. When I visually inspect the wheel well, I see nothing out of order.
What are the potential failure points that could be causing this sound? Should I take it to Discount Tire as a first stop, in case the wheel needs balancing or has cracked or the tire has an issue? Or am I wasting my time and I should just go straight to a qualified auto mechanic?
Does it sort of sound like when you drive on a really rough road surface, like it sounds driving on a road where the road crew has removed the top layer in prep for applying a new finish coat? And it gets louder the fast you go? If so, I concur w/DMP above, pretty good chance that’s a failing wheel bearing. Common sense says to ask a tire shop check the tire first of course.
Thanks, everyone. I guess the unfinished road analogy is somewhat accurate. But it COMPLETELY disappears below 65 MPH. It’s not a gradual diminution, it’s an on/off switch. Literally when it first happened I thought I would pull over and the tire would be in shreds, belt separation, something like that. And as I was changing lanes at 70 MPH (because it was a busy highway and I was in the far left lane), it almost felt or sounded like the tire was scraping the inside of the wheel well when I edged it right. But nothing on the tire or in the wheel well shows any signs of scraping, even when I turn it completely each direction and look under there with a flashlight.
It was not the road surface; the roads in question were some of the smoothest highways in Dallas. I was 10 miles from home when it started. Whenever I would speed up above 60/65 MPH, the noise would resume, below that it would stop-- highway, freeway, or six-lane road.
This weekend, I spotted a wire that looked like it had come loose from its harness, and might be flapping. So I duck taped it in place as an experiment, jumped in the car, drove on yet another road, and the same thing: above 60 it started, below it abated.
While making the noise change lanes (safely lol) to the right lane and then back to the left lane fast enough you can feel it and see if the noise gets louder and or quieter… Basically you will be loading the wheel bearing and unloading it (to an extent), if it gets louder moving right then it is your left bearing, louder moving left then it is the right bearing… More pressure normally equals more noise and less pressure equals les noise…
You can also lift the tire off the ground and check for play in the wheel…
While I concur w/MM above, still a good idea to at least ask your shop to check the other side for any bearing related issues, noise while hand spinning, unusual amount of in/out or twisting play, etc. My prior car, a VW Rabbit, had this problem while 1000 miles away from home-base, and I had the bearings on both sides replaced by a VW specialty shop. The shop folks told me only one side was making any noise or showing other symptoms in their manual-wheel rotation tests, but the bearing on the side that wasn’t showing symptoms was in worse condition than the symptomatic side. I guess what I’m saying is that, German car, if I had that problem, if one side was bad, I’d replace the bearings on both sides.
For anyone curious about the outcome here, it had nothing to do with the wheels or tires. I had apparently managed to pull the splash guard loose from the front bumper. It wasn’t hanging down dramatically, but there was an even 1/2" gap across the whole thing, such that above a certain speed, it naturally started to flap. I guess from where I was sitting in the driver’s seat, the sound appeared to be localized to the left side of the car.
I will have my indie BMW guy address this during an oil change next week, but for the time being, 12 healthy strips of T-REX tape seem to allow me to go upwards of 80 MPH with no noise.
One final question: I assume that I’m now getting a bit of unintentional air induction through that gap, since the T-REX tape can’t completely seal the gap, just prevent the flapping. I further assume that’s not a bad thing: just a bit more air to the bottom of the engine? There should be no rain between now and the oil change.
The biggest problem with not being able to see and or drive the vehicle to confirm the complaint is most mechanics do a walk around and look for stuff like that before and or after the test drive, it would be almost impossible to explain every single step that we do as pros that are so 2nd nature to us that we don’t think about it, kind of like breathing, you just do it… lol
Many years ago, a co-worker owned a fairly-new Continental Mark VI (a particularly terrible car to drive at more than… let’s say… 30 mph, due to the lousy brakes and horrendous handling), and she complained about a new noise when she drove it at highway speeds. A few days later, I drove next to and in front of her car in order to observe the behavior of the front wheels.
To my surprise, the flexible molding that served to bridge the gap between the bumper and the front fascia was–literally–flapping in the breeze when she hit highway speed. Simply securing that molding eliminated her noise problem, so I’m not that surprised to learn of the source of the OP’s noise problem.