(Final update 1/17) 300 miles and something's not right...
 

I picked up a 2015 BRZ limited on 12/31/14. I have just over 300 miles on the car and something doesn't feel right. I noticed it starting this weekend and it felt very prevalent just now on the drive home.

Between 2600 -3100 rpm (+-) it feels like there is a shudder coming from the rear passenger side tire and sometimes an odd vibration from the front passenger side that doesn't appear to be rpm related. I can replicate the rear vibration but not the front.

Has anyone experienced this? I tried searching but couldn't come up with anything. I've already checked the tire pressures and checked to make sure that the lug nuts are tight.

I have an appointment with the dealer tomorrow morning but the whole thing kinda has me bummed. Any possible insight you guys could provide would be appreciated.

Thx

Just wanted to add that I haven't hit anything, modded anything, or revved the car past 4000 rpm.

I have had the tires get flat spots overnite and vibrate the next day for a bit when they are cold. Also if it's on the same side of the car, may have picked up something off the road maybe?
I know you said it didn't feel like rpm related on the front, but this car transfers vibes, sounds etc very easily.

Hope you find it and it's an easy fix.
PAX

Thanks pax. I hope it's something simple as well.

Anyone else have something similar happen to them?

Is it happening at that engine RPM in every gear, or is it speed-related? My first guess would be that the shuddering wheel is just out of balance. I've had that happen on cars before (in my case because of snow / ice accumulation on the wheel, but it's possible someone just screwed up the weights and yours was never balanced correctly). At any rate, that's certainly an easy thing to check-- just have the dealer pull the wheel off and throw it on their machine. It should only take a couple of minutes.

I'm hoping it's something simple. The thing that's worrying is that it felt like it was getting worse last night. The vibration/shudder felt more prominent.

As others have said, one or more of the tires may have picked something up. If you are not at the dealer yet, turn the wheels side to side and try to examine the tread of the tires as much as you can.

I had something similar to what you were describing happen once to me and there was a fat screw head protruding almost a quarter of an inch above the tread of the tire, but I had not lost any pressure in that tire.

Hoping for something small...

I'm not sure if this is the same as yours but I've noticed whenever I started from a stop and slowly depress the gas. I'd feel a vibration coming from the rear wheels. I'm not sure if the wheels are slipping or if there's other stuff but I don't rev hard too. It does it at like 1500 rpm. This is slow start too so I have no idea.

Maybe it might be something similar? If anyone has any idea of this please let me know too. I'm thinking the rear tires are just slipping?

I agree with the comments on ice and flat spotting due to parking the car for an extended period in very cold temperatures....I lived in New York for eight years and had this issue.


Now on the west coast, I have had something similar happen, not long after receiving the car. In this case, it was gravel from the workplace parking lot causing imbalance in the wheels.


Having the balance checked should cure it, assuming it is not something more extreme.

300 miles and something's not right...
 

Vibration from rear wheels is something I feel on cold starts. I think it's something with the differential. Seems normal operation to me

I have 11k miles on my car, and I felt this the other night for the first time, when my car sat in the cold for a few hours (it was around 37 degrees, Socal never gets this cold). I even got out and checked if I had a flat tire because it felt so strange. I'm convinced it was either the tires being cold with a flat spot or as Pkush said, the diff being cold. It's since warmed up and haven't noticed it.

Yeah it's 0 degrees right now. I feel it every day lol.

I've noticed that too. Whenever i let off the clutch gently and only apply the minimal amount of power via the gas pedal...there's a strange sound coming from what I imagine to be the tranny/flywheel area that can be heard until about 2200-2300 rpm. Does that match what you've experienced?

Good idea and I have a plan. I'll update the thread on what was done/concluded below.

Thanks for the suggestion. I looked everything over. No screw or debris in the tire or the tire tread.

I was/am thinking it could be the diff. But that's a hard prove

Update: I took the car to the dealer this morning. The tech and I went for a test drive together... I told him how to replicate the vibration/shudder and he felt it too. We went back to the dealership and he put the car on the lift. We inspected everything and agreed that everything looked tight. I was able to have them throw it on the alignment rack and it was within spec, but not perfect or ideal. I'd have to get the print out to give you guys the figures.

At this point, I plan on finishing out the break in period and treating the vibration as 'whatever' until something develops (read: breaks [wishing nothing does]).

My plan is to have an alignment performed and dial in more negative camber up front for better turn in and to have the tires road force balanced and go from there. The car is a blast and still fun to drive so, no worries...for now.

On a side note, the tech was mad cool. He said they'll switch out the tranny and diff fluid for me with aftermarket fluids if I bring them in, so that's pretty sweet.

hmm shouldn't be that for me. I actually have an Auto. My rear wheels seem to vibrate like it's slipping on the ground. Just a little until it catches itself. Maybe that's when it's cold. Maybe you should take yours in to the dealers and get it checked out D:

yes i have a local alignment shop told me that every stock FRS/BRZ right side spec were off from his experience (even after change of suspension would be off more) ! I thought he was BS me

What are you driving on when you notice it? On some grooved highways, I notice a *lot* more tire noise and a slight amount of shuddering. Kind of like driving on a grated bridge, but not nearly as much twitchiness.

http://www.wsdot.wa.gov/NR/rdonlyres...istantView.JPG

Hahaha, I hate that texture so much.

Check that the nuts on the wheels are torqued correctly. All I have to add

Update: the car has over 800 miles and I can replicate the problem in 4th, 5th, and 6th gear between 2500 - 3100 rpm. It doesn't occur/isn't noticable at lower speeds ie 1st through 3rd. The best way I have been able to describe it is as a light infrequent, non-rhythmic, rotational thump that I feel in my ass and the small of my back that feels like it's coming from the rear pass side tire, wheel, axel, diff area.

I've been talking with CSG mike and we are both hoping that it is something as simple as he wheel and tire being out of balance. I'm taking the car to a tire shop for them to road force balance all 4 tires. I'm hoping that takes care of the problem. I'll keep you guys posted. Thanks for your help thus far...

@cwik - I feel it on any road surface and it doesn't feel like it's road surface related. I drove on a section of brand new/glass smooth asphalt the other night and I could still feel it.

It happens at the rpm range that I find myself in the most. It is beyond annoying and very alarming.

This is why you have a warranty. I would take it to the dealer. Don't just throw money at it.

So here's a little update. I took it for the balance and everything was perfect. A poor balance wasn't the cause.

I called the service manager at the dealership and he told me that the last time I was there the tech said that the car drove fine and he can't take his tech out of the bay to investigate. He told me to call my salesman and drive another 2015 for an apples to apples comparison.

Now i just don't want to deal with them and I have to find another dealer that's willing to take the time to figure it out.

It's bugging me to the point where it's taking the joy out of driving the car.

Fastest car in the world is a rental.

And that way you don't even have to rent it.

Have at, with all Kundam Soul Force.

Are you turning even slightly when you get this? In that case I would blame the diff. Mine was really tight when new and would shudder driving around the parking garage whenever I gave any amount of throttle and I wasn't travelling perfectly straight. It has since become a bit more progressive in the past year. The fact that you say it's related to RPM makes me think its related to torque output.


This car does have a very tight torsen diff. I get shudders and tiny chirps from the rear end whenever I need to quickly pull out into traffic. Below 2000 rpm this engine just doesn't have the torque to make the diff lock. Torque is relatively constant in the range you are talking about.


As far as the front vibration, I have no idea. The golden rule for mysterious tire vibrations is to rotate tires and see if the vibration moved.

Nope, I feel it when traveling in a straight line. Ive found that the easiest way to duplicate the vibration is to travel in a straight line in 5th gear right around 45-46 mph on a level road. Rpms should be right around 2500 to 2600 rpm. I feel it constantly at that range and then if I accelerate I can drive through it and make it go away, but if i decelerate back down to that speed rpm range you can clearly feel it.

I plan on taking it to a different dealer for them to look at it. I think my "dealer" only has the 1 tech...maybe 2. I also plan on writing to the GM of the dealership, the owner of the dealership, and Subaru of North America.

I'm sure they think that I'm having some sort of buyers remorse. I'm not. I knew what I was getting into with this car long before I purchased it (crickets, tail light condensation, notchy tranny, etc). I was not expecting for there to be a strange feeling in the diff.

I initially thought it was nothing, but after driving my buddies 2014 limited and noting that he didn't have the same vibration is when I started to become concerned. For me, potential problems with the diff are more disconcerting than problems with the engine or transmission. If either of those fail at speed, there's a good chance that you can bring it to a safe stop. If the diff gives out at speed, its going to unsettle the car.

This isnt my first RWD car either. 5spd/6spd RWD cars are all I've driven for the past 19 years.

I'm just going to have to take it to another dealer and hope that they don't blow me off the way that this one did.

I wonder if you have a genuine lemon on your hands. Contact Scion directly (not dealer). I bought my car in FL. On a new car the manufacturer has to fix the problem within 3 attempts from what I remember before you can file a defect notification form. After that, if they fail to correct the problem, you maybe entitled to a buy back or new car. Interesting problem, keep documentation of your contacts with Scion, and post updates as you find out more.

I don't know if I do, but I really hope I don't have a lemon. I'm still hoping its a simple fix. But I also want them to do whatever they have to do to fix it. I'll worry about what to do if they can't fix it, if that happens. Thanks for the information by the way. I'll research it more if the worst case senario becomes a reality.

Update

The car has around 970 miles on it now. The issue is still present. I took the car back to the dealer I bought it from and drove a brand new 2015 limited with a salesman. No vibration. Took the same salesman for a ride in mine car on the same route and he felt it. I told him about my experience with the service manager and he was shocked. He said he would talk with my salesman and the service manager tomorrow. He described it as feeling like something was opening and closing. [Turns out he's a car guy as well...he has a 700hp WRX]

Regardless of the above, I have an appointment with a different dealer in the morning. Hopefully everything will go smoothly and hopefully it will be an easy fix.

Final update: Took the car to another dealer yesterday. He car had 980ish miles on it. Met the service manager. Super cool guy. He's an ase certified mechanic with years of experience. Drives a subaru cross trek because he's an avid biker. Cool guy. I tell him about my issue and the vibration. He says he wants to go for a ride jumps in my car and we take off. I'm driving. I've told him what to list for and what to feel for.

I get up to speed/rpm and ask him if he feels it. With a bit of timing and queuing, he felt it. To the point where he was pointing out when he felt it. We got back to the dealership. He said they were gonna keep the car and inspect it thoroughly.

I left and went to work. Got a call from the service manager in the afternoon, he said that his tech drove the car and couldn't feel anything. So he went for a ride with the tech and pointed out the vibration. They went back to the dealership and drove another new 2015 limited and they felt the vibration. They then drove a brz with the factory 18" rims (I'm guessing series.blue) and they didn't feel the vibration.

They concluded that the vibration is a characteric of the car. He told me to keep en eye on it and bring it back if it gets worse. This isn't what I was hoping to hear, but I was ok with it. I was hoping to hear they found something that was loose and they tightened it and that resolved the problem. But I'm ok with hearing that 'nothing seems to be of a safety or mechanical concern with your car' at this time.

I even think I remember reading on here somewhere (long ago) that the designer of the twins originally designed the car to be driven on 18" wheels. Maybe I'll just swap out the wheels and tires go up to the 18's and see what happens.

Thanks to all for the input throughout. Any recommendations on good 18" rubber would be appreciated. I'm looking for more grip and maybe a bit quieter if possible. Tires on the old car were re760s and they were great. But I see that most people on here run pss or dunlops or hankooks. Might try the pss and see if I like them. Thanks again

I think you need to relax. Cars vibrate. Sports cars doubly so.

Make sure this is written somewhere in the service invoice. I had a similar problem on one of my tires (factory defect), took it to the dealer, and dealer said it was ok. Few months later the tire started to crack and the dealer said its because I hit something on the road. And the service guy never mentioned anything on my previous visit in the invoice and I did not have a proof.

I was able to convince the service manager to pay for the tire but it was pain.

As opposed to my visit at the first dealership, the second one opened a ticket and documented my concerns. So hopefully if anything happens down the road, it's documented.

I did kind of find a way to reduce feeling the vibration. I'm 6'1" and I had he seat all the way back and the back of the drivers seat was touching/resting on the rear seat and the carpeted sheet metal below it.

I figured that the direct contact was directly transmitting the feeling to my lower back and ass which is where i constantly felt the vibration. So I moved the seat up slightly so that there is no contact.

I can still feel the vibration, but i don't feel it as prominently as I did before.

step 1: Document at dealer. Done, good.
step 2: don't do anything to it, just have dealer try to fix it...
step 3: Keep going back to dealer to get it fixed.

If dealer can't fix the problem, or if it gets worse, then why not lemon the car? since you documented it so early, you'll get nearly exactly what you paid for it including interest.

I don't want to give up on the car just yet. I don't know if I'm hypersensitive to the vibration when it might just be something that is a normal characteristic of the the car.

Moving the seat up so that the back of the driver seat isn't making contact with the rear seat and the sheet metal below has helped to not transmit the vibration directly into my body via the seat-back as much, but I still feel it.

For now, I will keep an eye on it to see if it gets worse. I've cancelled all the plans I had in my head for fluids (motul - oil, tranny, & diff), suspension (springs and shocks/struts), wheels (18"), and tire mods as I don't want to have to deal with "the mod caused the problem" defense.

I might still consider a wheel and tire swap with something in the 17x7 - 17x7.5 size in the future because 1) I'm not a fan of how the stock rims look and 2) we get a lot of rain in the summer months and the stock tires don't inspire any amount of confidence in the wet at highway speeds. But for now, I don't plan on touching the car.

My number 1 concern has always been safety. If the vibration gets worse or if something breaks, then I'll be forced to consider all my options. If the issue leads to a failure which results in a loss of control and property damage/bodily injury then there will be a grossly different type of conversation to be had with Subaru and the two dealerships I went to... but that conversation won't be had by/with me.

If the car itself checked out ok, then I bet its a defective tire. It happens. Did you try rotating the tires to see if that changes the vibration?

Another possibility is the wheel hub/bearing assembly.
I curbed mine at the track, and it ended up with a a slight (but noticeable) droning vibration when I hit about 80-110kph, and then again at 130kph.
It was particularly noticeable when I made gradual right hand curves (felt it in the steering wheel and through the footwell). Mine turned out to be the front left wheel bearing. I replaced it myself after multiple useless appointments with Subaru service - I even told them what was wrong, and what I did to cause it (to their credit, the service manager initially said they would replace it under warranty if they found the issue).

Might be the rear bearing?

I have not tried rotating the tires as of yet. When I took the car to the tire shop and a) they didn't have a road force tire balancer and b) the right rear tire spun perfectly balanced I decided against rotating them and left.

I will try rotating them over the weekend. Scratch that, this weekend is the daytona 24. I'll try to rotate them some time this week.

I had been contemplating ditching the stock rubber right now anyway. It would be smart to rotate the tires before replacing them. Thanks.