Ather

Hi All, just purchased an 87 S4 and drove it home from AZ to the Bay Area CA. While driving I noticed a couple of things I was hoping to get expert feedback on.
1. There seems to an excessive amount of vibration in the steering wheel and dash that occurs when I reach speeds of 90 or more. It idles fine and drives smoothly at lower speeds so I'm not sure if its the motor mounts. I read other posts about MMs and they say that it would idle rough as well.

2. The steering wheel seems heavy but still quite responsive. I am a first time 928 owner so I am not sure what the norm is.

I know I should have gotten a PPI (shame on me for not doing that). The car was sitting around for a couple of years in the previous owners yard and was unregistered so driving it around was a bit of a problem. It has 124k miles and the engine is strong if that helps any.
Thanks,
Ather

Speedtoys

Steering in a 928 feels heavy...its just like that.

The vibration..wheel balance, bent wheel, bad tie rod ends, worn steering rack bushings...a bad tire even..etc.

auto, 5spd, pictures?

cpayne

Get the tires balanced. I had front tires put on acouple of months ago and things were fine until two weeks ago when i noticed higher speeds there was severe vibration. Took it to the tire shop had them balance them. Now smooth as silk YMMV

Jerry Feather

And, bad rear wheel bearing(s). Jerry Feather

jej3

+1 Did a high speed balance tonight @ Discount Tire. $60 out the door and a smile from ear to ear as 100MPH felt like 30 on the interstate!

SeanR

Could also be collapsed motor mounts.

Do the tires first.

Bill Ball

Do the wheel balance. Usually that's the cause of high speed vibrations if they are slightly out of balance. BUT if still present, then all the other things mentioned need to be checked.

Where in the Bay Area are you? If the tire balance does not eliminate it, I'd be happy to put the car on the lift at my house and check out the other possibilities Even if it does, we could give the car a decent examination for other issues.

Speedtoys

If you guys do this on a weekday, let me know..I may be able to cruise up and say hi.

Ather

Hey Guys, thanks for the input, you guys are great. I will try the wheel balance first and hopefully that will do the trick. If not then I'll move on to the other stuff.

Bill Ball, that would be awesome if you would be able to do that for me.
I am located in Palo Alto but am willing to go anywhere to get that done.
I am free on most evenings and weekends as long as the boss doesn't have any chores planned.

martinss

Left sitting for a "couple of years" will likely have caused flat spots the tires, especially if they are old, hardened and allowed to deflate, which is likely in a car that was not used much and then left to sit. You can determine the age of the tires from the sidewall code. I'd bet on some 10 year old tires... In such a case wheel balancing won't help, but is the obvious first thing to try. The tire tech will likely tell you about aged or out-of-round tires.

AO

I knew I had one dented wheel from hitting a pothole (damn Michigan roads!) and call a guy out to fix it. While he was there I decided to have the guy check the others. In all 3 of 4 were pretty bad. Even though all the weights are off the wheels, the car is silky smooth now! Best $250 I've spent in a while.

JoeTaylor

Congrats, must have been a fun ride home.

Ditto on the flat spots on tires.

When I bought my 928, it was only driven about 400 miles per year. Like new tires had flat spotted caused vibration around 85-90 mph.

It got better the more I drove the car, but a new set of tires fixed it. Smooth as glass now.

Joe

Ather

Didn't think about the aged tires and flat spots. Great advice, thanks guys! I will check it out.