sbZenth

iTrader: (23)

Driving at 40 mph and above, i feel rhythmic vibrations in the car.
I can hear it at slow speeds. it sounds like quiet humming. id say at a rate of 60 beats per minute starting around 40 mph and increasing slowly as speed increases.

if i pass 65, i can start to feel a matching rhythmic vibration in the driver seat.

my question is this,
the cars alignment is horribly off. the steering wheel isnt even centered. Could this be the cause of the sound? i havent had the chance to get an alignment because i havent been driving my car lately.

also, a month or two ago, i hit a curb with the front right wheel. it bent a control arm. i replaced it but im wondering if anything else that might be bent could be causing the vibration noises. i guess i will have to get an alignment and find out.


any input?

beetlejuice

iTrader: (1)

I've seen people experience something similar when their tires were out of balance.

It's also possible that you bent one of your wheels (during the accident which bet your control arm), which can cause odd vibrations / resonance at certain mph.

In addition, odd tire wear can also cause what you're experiencing.

So get the alignment, check your wheels & tires (have them balanced if not damaged), and check out your tire wear.

Blown shocks will also contribute to strange tire wear patterns, so that's something else to consider.

Good luck.

Spork

iTrader: (6)

1) Tires/Wheels out of balance
2) Wheel bearings
3) Defective tires
4) Unevenly worn tires, which leads to alignment or camber errors.

sbZenth

iTrader: (23)

thanks guys.

the right front wheel was bent, but now its fixed. the noise was there when i was on the spare as well.

I am getting an alignment tomorrow, and i will get the wheels balanced as well.

If that doesnt fix it, then i guess i will have to look at the wheel bearings. would wheel bearings get damaged when hitting a curb?

terrasmak

iTrader: (8)

Hub rings???

plumpzz

iTrader: (10)

I had this same problem. I hit a bad bump in the road. I had two problems. Bad alignment from hitting the bump, and damaged hubs on the left side (both wheels). Total cost?
80 for the alignment (I had to go to a speed shop with a low enough alignment machine)
800 including labor for replacing both hubs.

sbZenth

iTrader: (23)

shiot. i think the hub might be damaged then.

sbZenth

iTrader: (23)

i just got an alignment. The vibrations and the humming is still there. I asked them to check the hub as well, and the guy said that the hub was fine, and that he didnt see anything wrong with it.
I wonder if the wheels are out of balance? the thing is, i dont feel it in the steering wheel, so i dont think that this is the case.
Could the brakes be rubbing?

Are these specs good for the alignment, shouldnt the front cambers be closer to 0?

Q45tech

The vehicle speed and circumference of the tire can tell you where to look if you know the exact frequency of vibration...................for example a 26" tire rotating at 60 mph will create a 13 Hertz vibration with 1 bad spot on tire or wheel.

http://www.vibratesoftware.com/

Many high end dealerships have this along with test equipment to read frequency of vibrations.
http://www.boschdiagnostics.com/TEST.../Analyzer.aspx

Two different but close in frequency vibrations make create a sum and a difference beat which might feel like ~~ 1 HERTZ that will change and come and go, quiver in and out as phase changes.

sbZenth

iTrader: (23)

wow thats awesome.

ill definitely check that out. thanks a lot.

Q45tech

Be sure to test wheels without tires mounted. Oem specs for brand new wheels require that no wheel requires more than 5.0 grams on inner and 5.0 grams on outer side to achieve perfection [0/0 grams with +- 1.0 gram accuracy].
There are also runout specs which are almost impossible for aftermarket wheels to meet.

A Hunter 9700 radial force balancer should achieve 5.0 pounds [radial force imbalance] or less per mounted tire wheel with the arm set to exert the exact 700-900 pounds of squish weight to equal mounted location on car.........................another very tough test that factory tests before shipment.

Why factory doesn't warranty tires as they degrade in every mile of use.

wArt

Years back I had an Escort that experienced that rhythmic resonance sound and it was attributed to a bad rear strut causing a bit of cupping. Now I have a Cadillac STS that's doing the same thing. New tires (needed, anyhow) worked for a three months but now the rhythm is returning (heard at 35 MPH.)

It might be too early for new struts, at 38K miles, but replacing tires is no less expensive.

Q45tech

Only things that rotate or have a symmetrical pivot can cause a vibration.
Don't confuse shocks which dampen existing vibrations with causing them.

Always take a half dozen college physics courses to under things in the world.

bimmertech

iTrader: (10)

how low is your ride height?

that front camber is pretty high(to the negative side). i won't get into what the alignment guy did wrong here.

the wheel bearing is what causes the noises not the hub, so someone doing a visual inspection of the hub is useless. to check a wheel bearing, drive down the road at a speed to where the noise is present. move the car in a controlled "slalom" type manuver to load one side of the vehicle and remove the weight from the other side--just a little body roll will do. if the noise goes away when you do this then the unloaded side has a bad bearing.

wArt

Indeed. Decided to take it to a dealer today. Simply, it's aggressive tread. The car is RWD and the tires are new-ish (5k) of the high end unidirectional winter snow variety. Coupled with normal wear, it's an expected result. Alignment is good and struts are fine. I live NW of Chicago and will take control over noise, so when the winter departs I'll swap out the rear tires for the season.

An inexpensive diagnosis from an apparently honest dealer.

pchio

iTrader: (11)

When u bent your right front wheel, your wheel bearing may have a very high chance to get damaged. And it will makes the noise exactly as u described.

Do the test as what bimmertech said, so u can isolate if that is tires noise or wheel bearing noise.