^^ Thanks...just went looking for tires..$350-400 for tires

 

So with these vibrations my car vibrates more and has this grinding feel/low key noise coming from the car when going down hill..when i am at bottom of hill, it smooths out but not all the time.

As soon as my car sense a hill..it vibrates in the seat a great deal and you can hear this low key grinding noise. Someone today said it's my rotors..is this true?

 

maybe the rotors wore uneven, you could try some cheapo rotors from autozone or any car store and see if that helps

 

Why would it grind going down hills if its the rotors..i have heard that from numerous people just wondering why is that

My rear rotors do have some uneven groves in them..going to see if the tire place and machine them down to make them smooth

 

I had an appointment to get roadforce balancing on my wheels (roadforce balanced from the Tirerack when mounted) and was considering an alignment but that fell through. So I decide to replace my rear rotors and pads since the original oe pads had less than 5,000 miles left on them and some had reported improvement in vibration after doing the rears. Well guess what? The vibration I have at 75-85 mph really did improve! There is some vibration still but it feels more like road imperfections now and not the shake of imbalance.

 

Was your shake in the steering wheels? i just noticed today my rear rotors are starting to get some good groves in them

 

Yes, there was some shaking in the steering wheel. It is not as bad as what you had described though--certainly does not tire out my arms. Felt just like slight imbalance in the wheels. I did rotate the tires and the vibration was still there, more or less the same intensity. I do not generally balance my wheel/tires after mounting a new set but thought this might be the first time for me. I only have about 6000 miles on the wheels/tires though so I was doubtful that it was the balance but was at my wits end. I definitely ruled out a spacer issue since the vibration was still there after I took them off. I also had a recent alignment at the dealership but they saw my suspension stuff and said they could not guarantee anything except it that it drives straight(!!!).

 

Thanks..getting my rotors resurfaces when i get new wheels and tires put on

 

Can't believe it can't be fixed. 3 mechanics said they cant find whats wrong. Yet the symptoms are so cut and dry:

-Vibs for 8-10 seconds then 8-10 seconds of clear sailing..and this process repeats over and over again

-Also, when wheel is turned on highway going around turns...vibrations almost all go away..once i let my wheel go strait again..boom its back to vibrating bad

-19 inch tires and wheels made it 100 times worse..and i didn't think that was possible.

This is what i am still stumped about: When i had one tire shop balance my wheels about 2 months ago...it was silky smooth for 3-4 weeks until it started getting worse again..and now i cant get it back to the point of what it once was...

 

try to check the steering rack (i had mine replaced at 50000, because of the bad roads here...)

 

check your drive line, rear axle, transmission and engine mounts.

Also you need to eliminate all things possible to know where to look for vibrations.

To eliminate engine as a problem area
Get up to speed until you start getting vibration, let off the throttle and see if vibration goes away right away or only if car slows down

To eliminate transmission as a problem area
Get up to speed until you start getting vibration, put transmission in N and see if that does anything to a transmission.


If you eliminate engine and trans as a problem area, check your drive line for loose mounts or bolts.

Also check mounting bolts on rear pumpkin, make sure they are not loose.

 

Dealer checked all of those..trans..diff..rack..suspension..u joints..axles..everything

Basically myself and the dealer has eliminated everything. Dealer said there is nothing else they can look at and that they have never seen this before..so i am SOL...thats why i am trying to sell this thing ASAP

 

What? That's what he describes is a major issue with the wheels or suspension. If he has aftermarket wheels and doesn't have centering rings that would cause the vibration he's describing but it sure in hell isn't normal! I've had my coupe well over a 100 MPH and no vibration/shake or humming noises. Taking our Infinites to the dealerships is a waste of time for these kinda issues. Find a independent brake/alignment shop in your area they'll be able to spot the vibration cause easily. Going to the dealership with these issues is like going to the barber with a tooth ache.....lmao
Gary

 

Brought it to two independent shops already..they have no clue as well...they recommended me taking to the dealer..which i did..and nothing

Guess its just how my car is and it's quite sad

 

is it still under warranty?

You can try and lemon it.