I hate this about my car

[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

[jmabasa]

Isn't it dangerous to be driving with a missing lug nut?

[eslai]

It's even worse on these cars since we don't have lug studs and lug nuts. As blinkwatt said, we have straight-up lug BOLTS.

I wouldn't feel too comfortable driving around at high speeds with one missing.

[porsche986spyder]

Despite what your mechanic says about the wheel bearing, it could still be damaged. When your car is jacked up and the mechanic does the usual shaking of the tire and rim to see if it shimys back and forth to tell him that the wheel bearing is good or bad, this may not show it as being bad. It could still NOT have any movement and the bearing internaly could still be damaged because of the seals being broken or dented along the outside or inside rings. The bearing will still move without any obvious wheel slack, but may show or even sound like a humming noise at higher speeds.

I would still get that lug nut put on before you change out the wheel bearing. But if is the rear wheel that is missing the lug nut, I don't think you would feel it come up through the steering wheel.

[edevlin]

I am a big fan of getting the wheels road force balanced with a Hunter machine. I was having trouble with some vibration until I tried thier machines.

Ed

[pecivil]

me too. Had that vibration until Hunter balancing.

[djomlas]

yeah it wold be very dangerous to drive w one missing, but i guess if you only drive like that for a day or 2, but definitely not pushing the car like that and getting it up to 3 digits...
in my case the lug nut tool just broke in half, so went to the shop and got them taken out, and in the meantime i ordered some lug nuts that were off of gt2 (thats another performance mod right there hehehe, lol) and they came in within 2 days so it wasnt that bad.

[chaudanova]

Originally Posted by pecivil

me too. Had that vibration until Hunter balancing.

Pecivil, can you tell me where to get a Hunter balancing in San Diego?