bouncing/shaking emergency help! UPDATE

[bassthrive]

This is driving me nuts. At 25-30 mph I get a medium frequency up and down / slight side to side bouncing I can dramatically feel in the seat and again around 55 mph - I get a higher frequency vibration.

Had my tires balanced friday, all was satisfactory until my commute this morning. Yesterday I did a panic stop due to squirrel (that shouldnt have affected anything though). Struts and springs are almost a year old. Tires are 80-90%.

The bouncing at low speed is absolutely rediculous. Like someone is rapidly pulsing hydraulics.

What could cause the feeling of riding on square wheels besides balancing? Maybe a wheel weight fell off during my panic stop? Are my tokico struts blown (how do I diagnose this)? Are my wheel hubs/bearings shot? Need expert help here, and quick.

<update>
Replaced the defective tire causing the hop with a brand new one. Folks at TireRack gave me a 30% discount since there was not enough tread left to do a proper warranty claim. Smooth sailing again!

[SleeperSolara]

It might be the shock and struts.
You might want to check it oil leakin' out of them....
That all i can think of.

[~Spadwaller~]

Motor mounts?

[SC V6]

check and make sure your brakes arn't fu*ked

[bassthrive]

Brand new brembo blank rotors and ceramic pads. No shaking while braking. Alignment was done a month ago. Symptoms are solely dependant on forward velocity only. Happens regardless of throttle position, acceleration, braking or cruising.

bouncing at 25-30mph (almost like riding a trotting horse)
smooth around 40
fast vibration at 55-60
a little smoother at 70

will try going back to the shop that did my balancing after work.

[indiglosolara]

Do you have aftermarket wheels or OEM??

[bassthrive]

aftermarket 17's, and they've given me problems from day one, just never as bad as what i felt this morning.

why is it that whenever a problem like this shows up, it is intermittent, therefore impossible to get a mechanic in the car to physically experience the sensation? the ride home from work was fine! maybe because the car was cold in the morning? this morning was 20-30 degrees colder than usual jere in florida. ill give it a few more days before going back to the shop to see if the problem comes back.

[indiglosolara]

aftermarket 17's, and they've given me problems from day one, just never as bad as what i felt this morning.

why is it that whenever a problem like this shows up, it is intermittent, therefore impossible to get a mechanic in the car to physically experience the sensation? the ride home from work was fine! maybe because the car was cold in the morning? this morning was 20-30 degrees colder than usual jere in florida. ill give it a few more days before going back to the shop to see if the problem comes back.

Their could be a few problems that i can think of from experience:

1. You are missing the Hub Centric Rings that hold your wheel centered. Without this you get a vibration depending the speed is traveled( in your case from you description).

2. Your wheels are bent. You may need to put it on a high speed balancer to find out. Sometimes a wheel may not look bent at all but you can only tell on a true high speed balancer.

3. Rebalance your wheels. be sure to inspect your suspension while its all visable.

Hope this helps.

[bassthrive]

1. You are missing the Hub Centric Rings that hold your wheel centered. Without this you get a vibration depending the speed is traveled( in your case from you description).

Not missing rings, but they could possibly be damaged. My rims shipped with metal rings. Those vibrated considerably on round, balanced wheels so I had tirerack send me plastic rings which worked (for the time being). I suspect they are not as durable as the metal ones.

2. Your wheels are bent. You may need to put it on a high speed balancer to find out. Sometimes a wheel may not look bent at all but you can only tell on a true high speed balancer.

I asked the mechanic to check for bends when I got my wheels balanced on friday. He said they were perfect but I am skeptical of his diagnosis.

3. Rebalance your wheels. be sure to inspect your suspension while its all visable.

Doing that for sure. And I want to watch him spin the wheels on the dynamic balancer and look for wobble or dents. Thanks for your input!

[Jai_Jai_Binks]

i know you already said you took it to the shop, but besides what above has already been stated, just keep your hands over the tread and go around the tire...(i'm asking to see if the steel belts on the radial could be broken??)

[bassthrive]

Very close Jai! Brought her back to the shop yesterday and had them spin the wheels again. Turns out my rear driver's side tire has a hop (they didnt have a road force machine to fix this though). This tread is worn down to 40%. The other three tires are fairly new, due to several reasons (i.e. two originals wore out, one damaged when I got hit) Maybe at this point it would be wiser to mount a brand new tire instead of taking it to the shop down the road with the force balancer to quick-fix the problem?

[bassthrive]

update