Hey all, just looking for some expert opinions from anyone that may have had a similar issue:

95 coupe, auto, 15,xxx miles. Sat for 8 years in a garage before I bought it over the summer. Put on new wheels and tires and had the balance done twice cause I thought it felt “wobbly” the first time. Also had the new wheels checked for bends. They’re good. And the balance is confirmed good as well.

I get intermittent vibrations/wobbles in the car more often at higher speeds. However, sometimes around 50-60 it will become super smooth and ride like a magic carpet. But then other times at the same speed it will shake like a maraca. Speed doesn’t seem to be a factor as to a cause of the wobble. I do hear a bit of a “whirring” coming from the back wheels, but it’s hard to tell if that’s a bearing noise or a noisy u-joint (is that even a thing?), or the diff. My real question is: can a bad bearing cause an intermittent vibration? If not, what can? I have taken the car to a shop for a once over and they said they can’t believe how good it looks for it’s age underneath. The rubber all looks to be solid, suspension still nice and tight, and no accidents or anything that would knock out the alignment. But again it’s odd that it comes and goes the way it does. I’m going to put it up on jack stands this weekend if I have time and shake the wheels to check for an obvious bearing issue, but otherwise I’m at a loss. Anyone experience anything similar? Thanks!

 

I'd check the bushings

 

When you put new tires on, what tires did you put on exactly?

 

What did the rotors look like?

 

The rotors don’t look too bad. Since the car only had 14,000 miles on it when I got it, it still has the original brakes. I bought new pads and rotors for it which I have not installed yet, because it does feel like one or more of the rotors are warped when I brake. (Also because the current brakes are extremely dusty and are making a mess of my new wheels). I don’t imagine that would cause the kind of wobble I’m describing when not braking though, but I suppose it’s not helping any either.

 

The tires I put on are Khumo Ecsta PA51, size 275/40 ZR17 on all four corners, mounted on 17” A Mold wheels. The wheels are aftermarket wheels, but as I said they were checked and are perfectly round.

 

This is my feeling also. I wonder if sitting still for all those years has damaged and/or deteriorated them in some way. So that’s where I’ll start. Any other suggestions from someone who has experienced something similar is appreciated as well. Thanks!

 

Tires rotors warped, Have same C4 (93) I have found every i tem has to be perfect. The roads out there are not the best does the driving change on different road surfaces? Mine does 16000miles on mine. I have Goodyears .Another item is stones in tires and were do you park at night on the grass? In my opinion i will only use Michelins in the future and go to the shop with the latest balancing equipment. Cheap rubber on tires usually as the tire gets warmer smooths out not on the Michelins and that is what you pay more for the Michelins.Did you check the date on each khumo tire to make sure you have new stock and who did you purchase them from? I would only use a large tire shop like Tire Rack.com for rotation of stock because of large selling of wheels and tires. You want newly built tires for age breaks down rubber compunds! Did your car prior to purchase sit out side or in a warm garage ? Do you have the record of up keep on this car. Was the suspension placed on jack stands in storage and for how long? It is not recomended for a C4 in storage for any time period. Good Luck!

 

Lots of good point points here. Let’s see...

I will be changing the brakes, so if it’s the rotors I’ll know that as soon as I do that job. Yes, the roads out here are lousy, but I don’t think that’s effecting the specific problem I’m experiencing. The tires are brand new, got them from tire rack and made sure the rubber is fresh. No stones in tires either - I did check to see if anything was stuck in them or the wheels. I park on an asphalt driveway, no grass. This kind of intermittent wobble though indicates something in the suspension or bearings I would think. If it were the tires or wheels it would be constantly out of balance and not intermittent. Prior to purchase the car was in a garage, but it was not climate controlled and up here in NJ we get hot humid summers and cold freezing winters. The car was not stored on jack stands during that time, which was about 8 years. And my best guess because of that is bearings gone bad.

Thanks for your thoughts!

 

When you had the wheel off the ground did they have any side play, cause if it did might be your bearing.

There easy to replace, just time consuming.

 

I haven’t had it up in the air to check that just yet. I will definitely check all four wheels for wobble to see if the bearings show any play. And yeah, I’m not worried about doing the job, should be easy. Just don’t want to spend the money on new bearings if that’s not the issue. Which is why I’m here looking for other potential suggestions as to the possible cause. And as always, I appreciate everyone’s thoughts and suggestions very much! Thanks!