[Qasimateen]

Before going into the problem, here's a brief history of my 2008 e90 335i and what it went thru. I had 162 style rims and i bought m3 control arms as well as b4 bilstein suspension with stock springs (I only changed the shocks only, all those washers, bump stops, shock mounts, shock plates, etc. we not changed and reused with my new shocks) and everything was running normal especially at high speeds.
One day I ran into some 189 style rims that were for sale and personally I love those rims on my e90 rather than the ugly 162 style rims so I ended up buying them for a deal and sold my 162 rims. Turns out the front two rims were bent and my car vibrates like hell around 50mph so I took it to a rim repair shop and they fixed it (spent $300) and my car drove fine until I noticed the same problem but on the highway. My car STILL vibrates a little when I'm goin 70mph and progresses as I increase speed. By around 100mph my whole cabin shakes to a point where the whole cars literally jumps up and down rapidly which drives me crazy. Sure you can say slow down but even at 70-80mph it shakes where it gets annoying on the highway.
So I took it back to the shop and they said the rims were fine, they even showed me when spinning the wheel on their machine and to my eyes they do look fine, as compared to before the repair where the rim was wobbling up and down. So I thought it was a balancing issue
.
I did some research and ended up taking it to a shop which had those hunter road force balance machines and balanced my wheels thru that. The guys at the shop said they didn't find any problems with the rims or the tires. They said the wheels are perfectly balanced and ready to go but my cabin STILL SHAKES @70mph+

I have another e90 328i at home and I even spent the extra hour in switching the front two wheels (both 18x8) from both cars and drove both of them. After switching both front wheels I test drive both the cars and my 335i (with 328i wheels on) STILL shakes and my 328i (with 335i wheels on) drives smoothly.

At this point idk what to do because I inspected all my suspension components and everything looks normal on both sides but I still get this annoying small cabin vibration when cruising 70mph or higher on the highway. I may just end up buying two new rims to replace the two front rims but I don't wanna take the risk in spending the money and not having my issue resolved

I'm assuming it could be a bad sway bar or a bad steering rack or bad tie rod but idk if it causes small cabin vibration at high speeds.

Any suggestions??? Plz help I'm going crazy

[Tambohamilton]

I'd look at the driveshafts and centre bearing, rather than suspension joints. What you describe sounds much more like something (in the final drive) rotating out of balance, rather than a loose/worn joint.

However, if the vibration wasn't there before the new wheels, I'd be pointing the finger at them still, despite the shops saying they're balanced. Have you been able to swap out the rear wheels? I assume you're using the original wheel bolts too?

[Qasimateen]

Originally Posted by Tambohamilton

I'd look at the driveshafts and centre bearing, rather than suspension joints. What you describe sounds much more like something (in the final drive) rotating out of balance, rather than a loose/worn joint.

However, if the vibration wasn't there before the new wheels, I'd be pointing the finger at them still, despite the shops saying they're balanced. Have you been able to swap out the rear wheels? I assume you're using the original wheel bolts too?

My bolts are different since I have two different spacer sizes on the front and back. I'm assuming it's the rims too since the problem occurred as soon as I changed the rims. But the weird thing is that since I used my 328i wheels on the 335i to test the vibration, the vibration still persists so I'd assume it's not just the wheels, probably the suspension.

Just wondering where should I start or what should I change first

[Nautinto]

Start by removing your wheel spacers, cleaning the mating surfaces and use the original wheel bolts and then go out for a test drive. After that if it is still shaking, I'd be looking at the brake calipers if they are jamming, or looking if there is some pad residue on the discs causing vibration. If calipers are jamming, service them. Braking hard from 90mph down to maybe 20-30 a few times in a row and then driving around to cool the brakes should clean the discs from residue if that's the case.

But I'm pretty sure your spacers are causing your problems, so start with those.

[Tambohamilton]

Agreed; check (remove) the spacers. Make sure bolts also balance at each wheel.

[Qasimateen]

I removed my spacers and used the original bolts this morning. Still vibrates :/

Ima look more into the drivetrain stuff since I'm convinced it could be that

[Volasko]

You could check into cleaning the surface between the rotors and front hubs. If there was any debris or rusting when you did a rotor swap that could introduce a wheel wobble that could explain what you're experiencing.

Also I'm surprised people haven't mentioned your front tension strut control arm. Typically when the bushing wear on that it can introduce a vibration under braking at high speeds. Years back I was tracking down a similar strange vibration under braking at high speeds. Add that to the list.

[Qasimateen]

Literally bought rims for the front (tested did bends and it was all good) and I still have vibrations
This is frustrating

[Qasimateen]

Originally Posted by Volasko

You could check into cleaning the surface between the rotors and front hubs. If there was any debris or rusting when you did a rotor swap that could introduce a wheel wobble that could explain what you're experiencing.

Also I'm surprised people haven't mentioned your front tension strut control arm. Typically when the bushing wear on that it can introduce a vibration under braking at high speeds. Years back I was tracking down a similar strange vibration under braking at high speeds. Add that to the list.

Yea I upgraded my control arm and tension strut to m3 ones. It was fine after so I doubt it's related to that

[PhilNAmazing]

I have the similar problem where the whole car basically vibrates/shakes when driving on freeway (70+ mph). It gets worse as I accelerate, but none when I brake. Wheel balance and alignment were done and checked multiple times. I ended up finding out that my engine mounts caused the vibrations. Especially when my mileage is approaching 100k. So Im getting them changed out soon. Maybe something you can look into??

-Phillip

[Qasimateen]

Originally Posted by PhilNAmazing

I have the similar problem where the whole car basically vibrates/shakes when driving on freeway (70+ mph). It gets worse as I accelerate, but none when I brake. Wheel balance and alignment were done and checked multiple times. I ended up finding out that my engine mounts caused the vibrations. Especially when my mileage is approaching 100k. So Im getting them changed out soon. Maybe something you can look into??

-Phillip

I was actually just thinkin if it was related to my engine shaking. Yea I'm forsure gonna look into that now cuz I just came back from changing wheels and wheel bearings and the problem still persists.

[bt49qt28c]

Bro do you feel the vibrations in the steering wheel? Do you feel it on the ground of the car?

[Qasimateen]

Originally Posted by blagoja1

Bro do you feel the vibrations in the steering wheel? Do you feel it on the ground of the car?

I feel it EVERYWHERE. The whole dash the steering wheel the seats and the BACK SEATS!!!

[UncleShrek]

I have this issue as well, i too believe its the motor mounts. Ive got new wheels, new bushings up front, ive did the alignment, still shakes at high speeds.

[Nautinto]

Is the vibration correlating to vehicle velocity or engine rpm?

[bt49qt28c]

Did you try changing the back wheels? Back wheels often occur to start vibrating around 80mph and continously increasing until you reach around 120 mph and then it kind of dissapears. The vibration from back wheels can be around the whole car and mostly felt on the ground of the car. Also check your tires. Bad tyres ( tyres with deformations) not laying correctly on the ground could case big vibrations when driving faster.

[Qasimateen]

Originally Posted by blagoja1

Did you try changing the back wheels? Back wheels often occur to start vibrating around 80mph and continously increasing until you reach around 120 mph and then it kind of dissapears. The vibration from back wheels can be around the whole car and mostly felt on the ground of the car. Also check your tires. Bad tyres ( tyres with deformations) not laying correctly on the ground could case big vibrations when driving faster.

Wheels and tires are 100% not the problem. I literally switched my wheels and tires with another e90 I have at home and the same problem persists so it's for sure not wheels and tires

[Qasimateen]

Originally Posted by Nautinto

Is the vibration correlating to vehicle velocity or engine rpm?

I'm not sure tbh. I feel it at 75 but when I go 90 it gets worst and when I go 100 or 110 it's the same as 90

[bluewater328]

Have you considered the following:

- Wheel bearing(s)
- Transmission mounts
- Guibo
- Motor mounts

All of those reduce (or technically, can be the cause of) vibration in cabin.

[Qasimateen]

Originally Posted by bluewater328

Have you considered the following:

- Wheel bearing(s)
- Transmission mounts
- Guibo
- Motor mounts

All of those reduce (or technically, can be the cause of) vibration in cabin.

Wheel bearings I've changed. I'll look into the others

[bluewater328]

Originally Posted by Qasimateen

Wheel bearings I've changed. I'll look into the others

If you change the next two, you can do that at the same time.

Last one is one I am not looking forward to doing because of the subframe drop.

[Qasimateen]

Originally Posted by bluewater328

If you change the next two, you can do that at the same time.

Last one is one I am not looking forward to doing because of the subframe drop.

Yea the tranny mount and guibo are in the same area so ima tackle that first. If those don't solve then I guess last thing is motor mount. :/