This may be a tough question to answer since I can't say I've gone through all the possible variables, but here goes. I picked up a 2007 with 2650 original miles on it last week, carfax was clean and after giving it as thorough a visual inspection as possible, I feel confident that the car is in pretty good condition. However on the highway at speeds above 60mph, the car develops a shudder that shakes the entire car, and it gets worse as speeds increase. I've taken it up to 75mph and its pretty severe.

Lately the weather has been cold (temps are around 31* F when I'm driving home on the highway, typically when I can get it past 60mph) and I know the RE050 rubber can get a little stiff in the cold. But can that explain the shudder? Or might it be something else that I'm overlooking under the assumption that the car is barely broken in (pads or rotors degraded, etc)? I visually inspected the bushings under the car, no cracking or signs that they've dried/hardened.

Any thoughts?

 

I'd get the wheel/tire balances checked - I had a similiar issue too.

 

Word. Think I'm going to do that this weekend.

 

Sounds like a rear tire imbalance

 

I'm going to get them Roadforce balanced (or at least inspected) tomrorow. But looking at other threads, this seems like a deeper issue that isn't always solved by tires. Very interesting.

 

I would think it would be the tires since they are fairly old. Chances are a weight fell off or the tire is getting rotted so it may be time. Is the car stock? I assume so if it is still the OEM tires.

 

Yes car is completely stock. Inspected the tires for dry rot and flat spotting due to maybe sitting for too long, could not see anything but then again it was just eyeballing. Did check the wheel weights and no signs of any individual weights having fallen off (bare spots,debris clinging to old adhesive, etc) and didn't spot anything. Thinking maybe one or the bands in the tire may have shifted/slipped, had the issue on my Evo before but symptom was execesive uneven wear, don't see that on these tires.

 

https://www.s2ki.com/s2000/topic/100...ighway-speeds/

Sound like your issue? There's a link to another thread in there as well with more ppl with same issues. No one has come to any avail yet. Unfortunate.

 

yeah I'm in there too. Figured I'd get as many opinions on the board as possible. Will share what I find (if I find anything new) in both threads.

 

At the tire shop now. Preliminary verdict: bubble on the inside shoulder of the left rear. Horrible luck on 8/32 OEM tires. Getting it replaced and will have it on the highway this afternoon to confirm this was in fact the only cause.

Edit:confirmed tire was the issue. Took it on the highway, shudder is gone.