[Keyur Patel]

Hey guys, I need some input on a very weird problem I've been having with my car.

I bought the car (2014 Q50 Premium AWD) back in August 2015 as a CPO with about 17k miles on it. From the CarFax I saw that the car had been sitting in the lot 6-8 prior to me buying it in August. When I test drove the vehicle, I only did on local roads so I couldn't get a complete feel of it at higher speeds. After driving it home, I realized that the car vibrated when braking so the dealer replaced all 4 rotors for free (the rotors probably built up deposits on them since the car was sitting in the lot for a while).

That same week, I realized that the car had a slight vibration through the seats and floorboard/gas pedal at highway speeds (80+mph). The dealer offered to road force balance the tires, which did not help. I didn't like the run flats anyway so I changed the tires out to Continental DWS 06 tires and had them road force balanced, still a vibration from the rear. I swapped the rear wheels to the front and the front to the rear, but the vibration still did not change.

About a year later, I put 20" Vossens on the car (also road force balanced) and the vibration was much more noticeable, but also from the rear...nothing at all through the steering wheel. I guess the bigger wheels and lower profile tires amplified the vibration.

6 months go by and I upgraded to the Red Sport wheels with Michelin Pilot Sport AS3+ tires and the problem still persists to this day. Since then, I've also upgraded my rotors to the 2 piece rotors from Z1 and the big brake kit from the Q50 Sport.

At this point I'm thinking it's not a wheel/tire issue but something related to the suspension. Possibly bushings becoming brittle from the car sitting around so long before I bought it.

I've tried 2 different dealers and they keep insisting that the suspension is fine and I'm experiencing "road feel". I know it's not road feel because my other car that had low profile tires on it did not have a consistent vibration like my Q50 does.

What do you guys reccomend as a next step?

 

[shayer]

I'm gonna go on a limb and say check motor mounts?

 

[JohnsQ]

Check if the driveshaft is out of balance. I had it on my G37...chased wheels/tires for some time until a Nissan dealer finally identified the issue.

The 'test' is very simple - the vehicle has to be on a lift - the engine running and in gear. The driveshaft should be observed - should not see any 'hop' or vibration.

Best of luck...

 

[Keyur Patel]

Check if the driveshaft is out of balance. I had it on my G37...chased wheels/tires for some time until a Nissan dealer finally identified the issue.

The 'test' is very simple - the vehicle has to be on a lift - the engine running and in gear. The driveshaft should be observed - should not see any 'hop' or vibration.

Best of luck...

How many miles did your G37 have on it when you noticed the problem? My Q50 has about 43,000 miles on it.

 

[q50adix]

is the vibration accompanied by low frequency noise? if so, i could be the wheel hub bearing.

 

[Keyur Patel]

is the vibration accompanied by low frequency noise? if so, i could be the wheel hub bearing.

No noise at all, I've also tried pushing/pulling the rear wheels to check for any play, there's no play. I've heard bearings can be worn or bad but not make any noise or have any play.

 

[q50adix]

No noise at all, I've also tried pushing/pulling the rear wheels to check for any play, there's no play. I've heard bearings can be worn or bad but not make any noise or have any play.

It may not have any play but yes it does make noise for sure when it's worn out. Usually very low humming noise, and eventually leads to grinding noise if not replaced sooner. Might not be the same vibration you're experiencing though. If any of your wheels has no play over different bumps on the road and still feels solid, it's not your bushings. If you're convinced it's not the wheel hub bearing, then I think JohnsQ recommendation would be the next thing i'd look at.

 

[socal858]

I had the same issue - vibration started at 75mph and was most pronounced at 80mph. Aftermarket 19" wheels (vs OEM 17's) amplified the issue but it existed with the OEM wheels (and occured with both runflat and non-runflat tires). My suspension was OEM and the dealers said this was normal behavior....

Mine was bad enough that the seatback for the right passenger seat would shake from front to back. I started noticing the behavior around 23,000 miles on the vehicle and got rid of it at 28,000 miles.

 

[Keyur Patel]

I went to have my Fast Intentions catback put on earlier today and my mechanic noticed a transmission seal leak. Can this be the cause of the vibration? I attached a pic of the leak. I've also noticed the car makes a clunk noise when put into reverse and slightly jolts.

 

[SilverQCane]

Just a thought, a few months back, my Q50 had a differential leak. I was told that it is common with our cars and upon reading further, I read that if there isn't enough lubrication in the case, it can cause vibration in the rear section.

Doesn't hurt to have it looked at as well. It cost me nothing to get it fixed.

 

[Chief]

I went to have my Fast Intentions catback put on earlier today and my mechanic noticed a transmission seal leak. Can this be the cause of the vibration? I attached a pic of the leak. I've also noticed the car makes a clunk noise when put into reverse and slightly jolts.

An out of balance driveshaft will take out a seal.

 

[Keyur Patel]

Turns out it was a transfer case seal leak. Last time it was a real axle seal leak. I don't think it's a coincidence that I have a vibration from the rear and 2 seals go bad in 2 years. The dealer keeps insisting they don't feel a vibration.

 

[Keyur Patel]

I had the dealer look into that and they said it looked fine and they said the reason why the seal had issues twice is because of improper installation, but I think it's the driveshaft. I think it's also 2 different seals that had issues...the real axle seal and rear transfer case.

I was able to get a hold of the Road Force balance numbers and they are as follows:

Left Front - 12.13 lbs
Left Rear - 17.6 lbs
Right Front - 14.3 lbs
Right Rear - 6.6 lbs

I know that the machine "passes" anything under 20 lbs, but with low profile tires I should aim for 10-15lbs and under. I have a feeling that the dealer isn't match mounting the tires to the wheels to get the best result. I have Michelins so I would assume they are capable of running in single digit road force numbers.

 

[nr2134]

Is the car lowered?

 

[Keyur Patel]

No its stock height and suspension since I got it.

 

[Keyur Patel]

I've brought it to 2 dealerships multiple times and I keep getting the same old excuses about it being "road feel" or "could not replicate". One service advisor even went as far as saying that the issue is because of me replacing the stock 17" wheels with the 19" Red Sport wheels because my car wasn't "designed" for the sport wheels. That makes no sense because on the premium models, Infiniti offers the sport wheels as an option, but I didn't even bother to argue with the advisor at that point.

Anyways, since the dealers are being stubborn I'm not sure about how to go about getting a thorough inspection. I may have to take it to my local mechanic and get some type of proof of the real problem and bring it to the dealer to get it covered by warranty if possible.

 

[NERMAN]

I had the same issue - vibration started at 75mph and was most pronounced at 80mph. Aftermarket 19" wheels (vs OEM 17's) amplified the issue but it existed with the OEM wheels (and occured with both runflat and non-runflat tires). My suspension was OEM and the dealers said this was normal behavior....

Mine was bad enough that the seatback for the right passenger seat would shake from front to back. I started noticing the behavior around 23,000 miles on the vehicle and got rid of it at 28,000 miles.

Hey social, what did they fix to get the vibration to go away? This sounds like an issue I am having.

 

[Q50prowl]

I’m going through the exact same thing right now. I can’t figure out why I have a vibration for the last hundred thousand miles and I’ve been to the dealership eight times. They told me it was the rotors and finally after three brake jobs I just went and replaced everything with our r1concepts brake package and still vibrating wheel when braking

 

[Moodaddy]

Have the exact same problem as Social. Only happens when I approach 75-80mph. I've had the tires road forced balanced and rotated, all new rear brakes and new pads for the front. Still getting it though.

 

[Ripperdabg]

Did you guys resolve the problem ?
I think I'm having this issue too.