Alright - I've been browsing this forum obsessively for the past few months and finally decided to register for this.

I picked up an 08 TL-S 6MT about a month ago, and the thing drives like a dream with one (very significant) exception - there is an incredibly annoying vibration that starts anywhere between 100 and 110km/h (60-65ish) and does not disappear anywhere north of that.
I noticed it on day 1, it's not something that's developed over time.

I guess a test drive should have uncovered the issue, but the problem is I test drove another identical vehicle before pulling the trigger, and got them to go out and find this one for me (because I really wanted NBP)

Anyway, it's a high frequency shake, not a violent one. You can feel it in the wheel, you can feel it in the pedals, and the passengers can feel it in the floor.
You can actually look at the steering wheel and see it shake.

Took it back to the dealer last week - they did the obvious thing and balanced the tires, and assured me the problem would be gone..
It's not.

I'll take it back and get someone to go for a ride with me the second time around, but in the meantime I thought I'd run this past you guys.

I've done some research and the best I can find are these two threads:
https://acurazine.com/forums/showthread.php?t=90614
https://acurazine.com/forums/showthread.php?t=94301

problem is almost every single complaint in there is an 04 or 05, with an automatic transmission (the other scary thing of course is that some people could not get the problem solved..)

My first instinct was tires or wheels, but the thing that makes me suspicious is that sometimes it feels like the vibration goes away for a couple seconds at a time, even at a constant speed.

5th or 6th gear makes no difference, throttle on or off makes very little difference (but the shake feels a bit stronger with wide open throttle.. maybe it's my imagination)

Anyone seen this on a TL-S?
Ideas?

Thanks..

 

Have the dealer swap your rims and tires for a little bit and see if it goes away, it could be a bent rim or a tire with separating belts inside. This will eliminate any chance that it could be your tires/rims.

If that solves it, then you know you have a problem with the rim/tire. But if it doesn't work your way back, have them check the suspension, esp. the half shafts and anything else in that region.

also on a side note, have them check and neutralize the motor mounts, that might be the issue to.

 

Took one of the mechanics for a ride today to show it to him-
He swears up and down that it can't be anything but the tires/rims.

They insisted I get it road force balanced before they start looking any deeper, so they'll be doing that next week and we'll see...