Hi all - my first post. I have an '08 G35X with Auto trans and 51k miles. Over the last week - when i get up to highway speed (50mph+) - the whole car shakes disturbingly. Feel it in the seat - and can hear the vibration. After about 5 miles or so at highway speed - it goes away and smooth as normal. The car is already warm by this point in my daily commute - so - it is not the tires or anything. There is no discernable noise that would indicate anything - just an unnerving vibration in the whole car (if i had to guess - i would say rear wheels)
U joint? Wheel bearing? Suspension component? Any ideas?
Thanks much

 

Begin by having your tires balanced, ask them to look at the tires for a broken belt or tire out of round. If that doesn't cure your issues (I believe it will) find a independent brake/alignment shop to check your suspension out...Gary

 

Thanks Gary - they are new Continental Pure Contact tires with less than 5k miles. Dont think it is the tires - because after a few miles of highway speeds -the vibration goes away.

I will call the dealership and see what they say. BTW - i live in Rochester, NY - and it has been unbelievably cold with snow/ice for almost a week. Supposed to thaw a little this weekend - will see if there is any differnce.

 

The fact that it goes away after driving on highway for a bit makes my first hunch being tires. It's been ridiculously cold the past week so it's quite possible they have a flat spot on them in the mornings that then work out after the tire warms up on the highway. Your car may be warm from city driving but the tires need some higher speeds to warm up.

Wait until it warms up a bit before going out and having things replaced.

 

You Live in Rochester. You probably have snow up there. You probably have snow/ice somewhere on the inside of your rims and/or wheel well. Make sure all snow is cleaned out.

 

not snow or ice build up - checked that twice and brought to a car wash. But thanks for the suggestion!

 

I called the local dealership (Dorschel Infiniti) and they had never heard of this problem before on a G35X. He even suggested it could be a transmission issue - but would have to have a tech look at it.
I will make more observations over the weekend to see what other symptoms i can discover and will be sure to update this thread in case anyone else has this issue.

thanks all!

 

Lost180 might be right, with your right coast temps it's possible the tires aren't totally round until they thaw out giving you a terrible ride. Is your G garaged? If not flat spotting is even more a possibility.
Gary

 

I just had a similar problem on my G, but it went away after it warmed up a bit (from 5-15 degrees to 35-40 degrees).

Good luck

 

Back from the dealer - turned out to be a "dragging" caliper. $300 later - all is well. Strange symptoms though.
On Saturday - when the temps here in Rochester got up to 50 degrees - i noticed heat and the sound of metal contracting in the left rear wheel. That gave me a clue - but i was still thinking it was a wheel bearing.
Oh well, Thanks all.

 

Did the caliper have to be replaced?

 

yes, replaced the caliper. The rotor had been worn down about 30% on that side as a result. The shoe on that side had some "glazing" on it -tried to get me to get a rear break job with rotors for $700+ !!!! Yikes!
Drove it to work - smooth as silk again