Suspension also looked okay? And I assume it was stock? Because people have reported vibrations at higher speeds on the Q50 when lowered in particular. Buut it could be bushings, endlinks , tie rods or wheel bearings. Heck even wind resistance on a part of the car tcan cause vibrations within the cabin.

As other forums suggested if there is movement in your drive shaft, the transfer case or differential it could also explain the vibrations.

 

Inspect the rear driveshaft - bad u-joints? bad carrier bearing?

 

Are ALL lug nuts torque properly?

 

Man, that's a long time to live with a problem. Has a balancing weight come off the driveshaft? I was going to suggest a broken belt in a tire, but I see you replaced them. Has the dealer confirmed that there is an issue and put it in writing? It might be time to go to a specialty shop and pay out of pocket. This is one local to me that I would be tempted to try if wheels, tires, and rotors have all been checked out and found to not be the issue.

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Any aftermarket parts in the driveline or suspension? Were the wheels swapped/rotated in an attempt to isolate the issue? I know you said you had your tires replaced but most shops just put the same wheel back where it came off. And I assume you replaced all 4 tires at the same time.

 

Torque converter out of balance? Just trying to think of things that spin.

 

All stock, no modification or aftermarket parts. Today i took it to local mechanic they lifted car and put in gear. It seemed like rear differential. They said rear differential or driveshaft. They gave me a paper i will take it to dealer on next Wednesday. If they said nothing wrong it is time to talk to infiniti

 

Did they say anything in particular, like hearing something weird or actually saw it vibrated? How's the subframe bushing btw?

Keep us posted!

 

Hmmm... I wonder, since it is AWD, if the rear driveshaft can be disconnected, and drive it to see if the vibration disappears? I don't know how the transfer case would handle a disconnected rear driveshaft.

 

Today i was driving on highway, around 80 mph i put in neutral and still vibrations there. So if it was driveshaft or differential, it wouldn’t do that in neutral since there is no connection while in neutral ??
Other question is, can bent wheel be balanced as a wheel without bent? I mean if it passes balance machine that means there is no bent wheel???

 

Other question is, can bent wheel be balanced as a wheel without bent? I mean if it passes balance machine that means there is no bent wheel???

Yes, the tires of a bent wheel can be balanced at a tire shop. No, if the tire of the bent wheel can be balanced, it does not mean that the wheel is not bent. If one of your wheels is bent, I suggest you bring the bent wheel to a local wheel repair shop to get the wheel as round as possible.

Are one (or some) of your wheels bent?

The other day when I was getting two new rear tires put onto my car at America’s Tire, one of the techs notified me that one of my front aftermarket wheels was bent (I had them balance the front tires for me). I, too, am getting a vibration from my passenger side seat at 20+ mph on my 2017 Q50 RS RWD with 68k miles. As soon as I get the time to, I’m gonna bring my car into a wheel repair shop to get the bent wheel repaired. Hopefully this will fix the passenger seat vibration...

 

One other thing to note...

I did take my car in for a warranty service at around 22k miles due to the passenger seat vibrating/rattling. Infiniti ended up replacing the seat mounting nuts and the seat frame assembly. It lessened the vibrations/rattles, but did not completely eliminate the vibrations/rattles. They stated “slight vibration from pass seat, this is normal operation if there is no passenger. Fault corrected.” I’ve been living with the slight vibration... Doesn’t bother me all that much.

 

After rebalance today, car shakes more than ever. Wheels have been checked for bent, everything seemed fine. I don't know whats wrong with this car, i have appointment on Wednesday 1/29 Infiniti Motorwerks in Barrington, IL

 

I assume you had the wheels balanced again? Please tell me this is a competent shop with modern equipment and not your neighbor static balancing the wheels in his garage.

 

It is discount tire. I bought my tires and had them rebalanced 3 times. And once at pepboys. Pepboys was spin balance but discount tire supposed to be roadforce.

i will take it to another shop with hunter 9700 and will ask them about RF numbers

 

Today I dropped my car off to dealer. We went to a road test, technician felt vibrations. I am waiting for their diagnosis?

 

Different dealer or the one is has been checked by "many times" according to your original post?

 

It's really a shame the previous tire techs didn't recognize the bent wheel. It is a rather obvious condition, especially during a spin balance.

 

I hope the car would be fixed. i will not pay anything until test drive before pick it up

 

Finally it has been fixed. They found out there was slight bent on rim. And they did roadforce balance. Now smooth as silk. I just dont get it how other shops couldnt find that issue, discount tire pepboys midas

 

Glad you got it fixed, but holy baby Jesus...you have no shortage of incompetent techs in your area.

 

It was nice for a couple days now started again. I took it local mechanic who has hunter 9700 balance machine, after my tires roadforce balance checked these are numbers my tires,

LF 16 / LR 31 / RF 21 / RR 36

now i went back to discount tire, i was told they cant go lower than 20 it is impossible. I said tires need to be lower than 15 at least.

upper ones from local mechanic with hunter 9700

hand writing ones from discount tire. Now discount tire will replace two of the tires since they are defective

Same discount tire store told me my tires were ok within last 10k miles and after 3 rebalancing now they are telling me two tires defective.

 

It was nice for a couple days now started again. I took it local mechanic who has hunter 9700 balance machine, after my tires roadforce balance checked these are numbers my tires,

LF 16 / LR 31 / RF 21 / RR 36

now i went back to discount tire, i was told they cant go lower than 20 it is impossible. I said tires need to be lower than 15 at least.
View attachment 90437

upper ones from local mechanic with hunter 9700

hand writing ones from discount tire. Now discount tire will replace two of the tires since they are defective

Same discount tire store told me my tires were ok within last 10k miles and after 3 rebalancing now they are telling me two tires defective.

I don't know if you mentioned it anywhere but what brand and model of tire do you have?

 

I now feel like I have a bent wheel too. Been following this thread to see the final outcome. I have a 2015 Q50 (not AWD). Have had aftermarket wheels for a while. Never felt any vibrations even north of 120mph just smooth. Had one of my cheap aftermarket TPMS fail, possibly due to hitting a pothole? Put my factory wheels and tires back on, still smooth. Finally got my TPMS fixed and put the wheels back on and now feel vibrations starting around 75mph and the vibration increases as the speed increases. I have had the balancing checked a few times from a few different shops, all have said it is fine. I suppose it's time to have them checked to see if there are any bends.

 

best roadforce numbers i could get,

front 12 and 17 rears 22 and 22. vibrations are very minor now. i am done with that issue.

 

So, I’m experiencing similar symptoms. 70+ mph. More like a oscillating vibration. Feel it in seats and steering wheel. Feels like if you attached a magnet to tip of a drill and spun it. I’ve done similar diagnosis including replacing wheels/tires/rotors wheel balancing, and alignment. Can visually see the oscillating vibration when my phone is on the mount. Don’t know where else to go from this

 

Try a driveline specialty shop. Maybe an axle or driveshaft has lost a balancing weight.

 

Did you ever have a Hunter Road Force balance done on the car?