996 C4s Vibrations at 65-75 mph

Hi guys, I have a 2002 C4s that has been giving me a vibration in the steering wheel at around 70 mph but it almost goes away at about 85, I was thinking it was due to a tire balancing issue. I brought it in for a tire rebalance and alignment at a local shop (Boston) that was recommended to me. I was hoping this would solve my problem but on my way home I still found the vibration in the wheel but it does feel a little better, hard to say how much better though. Has anyone ran into a vibration issue due to alignment being out? How concerning are the below results? It was suggested I replace my suspension for any additional improvement. Below is my before and after (highlighted note at bottom):

Before you spend a lot trying to sort this out. Take it to a good tire shop and have them dynamically balance them. I don't remember if there are any Discount Tire shops in Mass. but they have the best equipment I've seen anywhere. Twice I have had symptoms almost identical to yours with tires and both times it was balance. The first time I had the balance done three times until they got it right. The second time the balancer told me the tires were out of spec. Instead of taking his word for it and spending a couple hundred dollars fixing it, I took it down the street to Discount. 30 minutes and $18.00 later. They were perfect. Good luck.

Could be a lot of things. What do the tires look like? Brand? Age? Tread wear?

Tires are Continental DWS06, 3 years old with about 15k on them. Tread wear is even and nothing visually abnormal. I was really thinking the balancing would have solved it but as tharbin pointed out perhaps it's still a balance issue. Thanks for the replies

Steering wheel shake is almost always front tire or bent wheel. Insure tire psi is within spec, I bet you have a bent wheel. If you see the bare wheel spin on a tire balancer it will be obvious.

+1 on checking the tires and rims. Had a similar problem with my VW, had a bent rim. Got the fixed and no more issues.

Ok, I'll reach out to a shop that can look at the wheel for bends, there looks to be a local shop that does a good job with this. Is it common for alignment camber to not be adjusted? Or new suspension to be needed to bring it in? I've been looking into coilovers but wasn't expecting to invest in them this year.

Alignment won�t fix your shaking, but will fix tire wear and road wandering. This is more than likely a tire issue

Ok, can a bent wheel be detected with a Road Force balance?

Any balancer will visually show a bent wheel, the road force balancer is the latest technology that will provide a better job.

To follow up- returned to the shop for a second attempt at balancing, this time it was a success, no vibrations. Root cause was the balancing. Thanks all for the replies.

Had a similar problem. Always had a slight vibration from the time I bought it with 23K miles. Switched tire to pilots and it got much better. Just changed to Bridgestones and it got really bad... Three attempts at road force balance just made it worse. Car has 98K miles now. Short answer... Rim shop found two bent wheels. Car is much better now. Side note - don't think the Bridgestones ride as smooth as the pilots. In the process had an inde shop align it. Was worth it but no vibration improvement there. Get the wheels checked QUOTE=About2Bite;17473636]Hi guys, I have a 2002 C4s that has been giving me a vibration in the steering wheel at around 70 mph but it almost goes away at about 85, I was thinking it was due to a tire balancing issue. I brought it in for a tire rebalance and alignment at a local shop (Boston) that was recommended to me. I was hoping this would solve my problem but on my way home I still found the vibration in the wheel but it does feel a little better, hard to say how much better though. Has anyone ran into a vibration issue due to alignment being out? How concerning are the below results? It was suggested I replace my suspension for any additional improvement. Below is my before and after (highlighted note at bottom): [/QUOTE]