Hunting down weird vibration
 

Ok so I’ve written this out three times already and this dumb forum keeps deleting what I type out but I guess it’s my fault for not saving what I’m typed before I press post. My past posts were more detailed but at this point I’m pissed and I really don’t feel like typing all that all over again.

Back to the original topic: Vibrations.

Long story short I just recently bought my G37X. Wonderful car and I really love it but I can’t pin down this vibration problem. Basically my entire car vibrates intermittently from about 65mph to 75mph. Anything above 75mph you can’t really feel the vibrations(Don’t quote me on this, maybe i can’t feel it but it’s probably still there lol) The weird thing is that it comes and goes every couple seconds. It’ll vibrate maybe 15 seconds and then stop completely for around 5 seconds and just repeat over and over.

So far I’ve replaced the front passenger side CV axle because the boot was torn and leaking and also balanced all four tires but that didn’t fix my problem. I later replaced the front two wheel bearings but that didn’t fix anything either so I went ahead and bought four new Michelin Pilot Sport A/S 3+. Fixed what I thought was wheel bearing humming but did not fix the vibration. I proceeded to inspect my car and noticed the upper passenger side ball joint is torn so I went ahead and ordered a new upper control arm w/ the ball joint obviously. In my past experiences I’ve had bad ball joints but have not experienced the weird intermittent vibration and at this point I’m worried I’m gonna fix the ball joint and the vibration is still gonna be there.

So has anyone on this forum experienced this problem? If so what’d you do to fix it?! Thank you all in advanced!

PS: I’ve been a long time forum lurker just never had an account to post with lol, hopefully you guys can help me fix this issue because it’s driving me insane and again thank you.

you said you balanced the tires, but didn't say you rotated them. another thing you may want to check - make sure all tires are 1) the same size and 2) "outside" is on the outside. i've had tires mounted wrong (inside-outside). just a thought, and easy to check.

other than that, i got nothing... :(

I bought four new tires lol no need for rotation they have under 100 miles on them and yeah they are all the same size. I don’t think the tires are mounted wrong because when I changed to the new tires the vibration continued the exact same way so idk.. I guess we are both stumped lol

Whole-chassis vibrations tends to come from the drivetrain or rear tires. Look there instead of the front of the car.

when you say drive train what should I look at specifically? I can definitely cross tires off the list.. a friend told me to see if somethings wrong with my drive shaft.. I don’t know exactly what to look at though lol

You have two drive shafts, one to the rear diff and the other to the transfer case. See if the rear drive shaft u-joints are worn. Try twisting the shaft back-and-forth looking for slack between the u-joint parts. Ignore the slack in the diff.

I haven’t checked the u-joint yet but I just had a thought.. The vibration I’m experiencing is intermittent.. wouldn’t a vibration caused by the drive shaft be more constant? Considering the drive shaft spins roughly 3-4 times faster than the tires do, the vibration caused by a drive shaft issue should be much more constant. I’m no mechanic so correct me if I’m wrong, I’m just trying to put things together here lol

It could be a resonant frequency thing (like an out-of-balance tire) but yours is a valid thought.

I don’t even know what to look for anymore lol :confused2:

Same here - I have a similar vibration in my 2011 G37x Sedan. Also comes and goes and is easier to notice on smoother roads.

I don't spend enough time on the highway to be bothered enough to hunt the issue down, however it doesn't change after rotating the tires. I bought the car used and the tires were brand new so I don't have experience before the iMove tires were installed.

Infiniti does have a technical service bulletin on the car for similar noise attributed to the driveshaft binding however my production date isn't supposed to be impacted and when I called Infiniti they indicated my car has never had a warranty claim. It looks easy in the TSB however it seems I need to drop the exhaust to access the bolts:
https://infinitig37.com/TSB/ITB11-019.pdf

Others have mentioned the issue caused by a worn center bearing on the drive shaft.

Interested in what you find.

-Eric

Is your steering wheel shaking? Or do you feel it mostly on your seat?

I would go back and have them rebalance all the tires before doing anything else. Everything you are describing sounds like a wheel issue.

Did you ever figure this out? I’m having a similar problem except I can feel the vibration at a lot smaller intervals (comes and goes instantly). I can feel it in my seat too. Super annoying

If you experience vibration at relatively high speed it could be your car struts/ shocks getting worn out. My mechanic says this is cause of vibration at high speed.

Or could be stuck brake caliper also. Or broken engine mount. Or driveshaft got slightly bent.

I am just going to throw this out there. As I was chasing a vibration issue for a while. I did what everyone says check tires and wheels, I had them balanced a lot of times and even road force, never solved the issue. Symptoms where rear windshield would vibrate on the highway, rear view mirror would be very blurry at 70 MPH, loud sort of humming would come from the rear. There would be a heavy vibration through the center console, seats and steering wheel. It felt like an oscillation (something spinning off center or "orbiting") Most shops struggle a lot with pin pointing vibration issues and often will give a wrong diagnosis, at least in my case. As well as the car being AWD it only makes diagnosing it even more difficult. Long story short, replacing the rear drive shaft with a new OEM unit (not an aftermarket one) fixed the issue for me. This unit needs to be installed correctly (run-out checked and any indexing needed), with new hardware (brackets and fasteners) and everything torqued to spec. These cars are way too finicky to not be torquing items to spec let alone the correct sequence.

A shop with a vibration analyzer or the NVH app might be able to better pin point this issue. Anyone can get the NVH app, though its $100 and needs to be used with ideally a second person to have it at or closest to the vibration source. If not place it in a cup holder or a phone mount. The results it gives will not exactly tell you the issue but it can help point you toward a possible source. I actually got this app a while ago to test it out and it's interesting to say the least.

https://vibratesoftware.com/

I found the Pilot Sport A/S 3+ to be too stiff of a tire and will transmit a lot of the "road feel" to the car and can make for a very harsh ride as the G already has a stiff suspension IMO. They are awesome in the rain and handle snow without issue (paired with the G's AWD setup make for a potent combo), they are probably suited for areas with proper roads and highways unlike where I am. Michelin makes exceptional tires but these I find are not good in terms of ride comfort IMO.

What I replaced during the whole thing was... a lot of parts (replaced with OEM parts), but the rear driveshaft basically fixed my issue.

Rebro TSB (ITB11-019) only affects certain VIN's after 2010, if you do perform it, I would of course use new hardware (TSB and FSM calls for this). My VIN was not affected, but I still performed it when I was trying to figure out the issue, it did not fix it for me.

Sorry if this is not exactly like your issue, but I figured I would throw this out there as you have an X as well.