I hate this about my car

[Stunin_Stud]

Ok I have read post about this before but its has not answered my question. My car vibrates or shakes and you can feel it through the steering wheel when I go 85 to 95 mph then its goes away and comes back at 106 and then goes a fades a little at 110. at 35 mph it makes a howling noise like tire sound. Mechanic said its not wheel bearing. The allignment seems fine. I have ballanced it twice before but I think I should do it again. one of my rear wheels is missing a lug nut because the tire center lost it. maybe thats a reason I dont know. All i know is that Its very tiresome driving my car fast because it vibrates too much. I have a corolla and it goes these speeds with ease with no fuss. I get too much feedback from the road. on bad roads i feel like its gonna vibrate off the road. My suspension seems very stiff too maybe thats why. The mechanic said my tires are not too smooth. theyre fairly new tho, although cheap. Im running Sumotumo HTRZII all around.

any Ideas guys?

[blinkwatt]

First thing is first,get another lug bolt.

[humara]

probably good idea to keep it under 100 until you do get that lug nut.

[Adam]

I don't think there is anything wrong with your car other than missing a lug bolt. My boxster shakes a little too sometimes and has stiff suspension. This car is going to give you more road feedback than a Corolla because it's a sports car, not an econo grocery getter.

[RandallNeighbour]

The first set of tires I put on my boxster had at least one out of round tire, and it caused the exact problems you are describing. I bought a set of Sumitomo HTRZII's and had them road-force balanced on a Hunter 9700 series machine and the problem went away... the car was smooth at any speed.

As others said, get that missing lug nut on the wheel and drive it again at 85 and see how it acts. If it vibrates, I'd say you should get the front wheels road-forced balanced. Some Discount Tire Company stores have the machine.

Then drive the car again. If this doesn't fix the problem, I'd say one or both of the front tires are out of round. There's no way to fix this that I know of.

My out of round tires were Kumho's, by the way ... another budget tire for our cars.

My third set of tires, required for larger rims I purchased at the beginning of this year, are Michelins. I spent the big bucks for two primary reasons:

1. I have far better wet traction and they're far less noisy than cheap tires as they've worn. My Kumho's got really loud after about 7,500 miles.
2. None of them are out of round, and I have zero vibration other than road feel response, which we need to drive safely at speed.

Hope this helps!

[djomlas]

i had vibrations that you are describing when i didn't have all 5 lug nuts when my key for opening the lug nuts broke. ordered new lug nuts and put them on, problem solved.
do that first, get the lug nut, and go from there

[racer_d]

Originally Posted by Stunin_Stud

...I get too much feedback from the road...

For many people, that is why they drive a boxster. Feedback is good! 18" wheels, M030.. it should be "stiff". Then again, maybe another Corolla would be more appropriate,

As for vibration, I would get all lug bolts installed and torqued to the correct tightness. I would encourage a "road force" mounting/balancing. It is concievable that after some miles the tires can become "unbalanced". Also, it could be possible that a wheel weight has come off a rim.

[Perfectlap]

lug nuts are over rated... So is correct tire pressure and wheel alignments.
What's next? buying one of those silly torque wrenches?!
You Porsche guys need to chill out and have faith that nothing will go wrong.