2015 F30 320i vibration at high speed

[Glenn_]

Hi everyone,​

I have been dealing with this problem for almost two weeks now, the car is shaking/vibrating from 110km/h and highly noticeable at 120km/h. I have experienced a similar problem in the past(2-3 times) and fixed it by straightening the rims and balancing the tires.

This is what I have done so far,

• Replaced rear and front shocks
• Straightened the rims
• Replaced tires
• Balancing and alignment(went to probably 5 different tire shops)
• Inspected the whole suspension, including propshaft and driveshafts and all is good

I did balancing a TWT after straightening the rims but no changes. Today I took the guys who fixed the rims to TWT with me and they put all the tires on the thingy and they all confirmed that the wheels as moving fine, no buckles. Went for a test drive, car still shaking. They said I should get a second opinion and referred me to Motorvison, done the balancing and also checked the whole suspension and all is good. Took it for a drive, car still shaking - it's driving me crazy now.

The steering doesn't shake, it's just the passenger seat that is shaking and I can feel the chassis vibrating as well - mostly the front. between 110 and 130 the seat shakes, at 140-155 the seat stops but I can still feel the vibration. At 160 the seat starts again

I don't know what else to do, please assist.

 

[DarrylvanNiekerk]

I'm assuming all control arms are tight and not worn, is the sub frame tightened properly to the chassis?

Does the car wander or tramline at all or just vibrate?

Maybe try and get it onto a dyno and see if it is the rear that is a problem or the front, might narrow things down?

 

[Faraaz001]

Sounds ridiculous I know but from experience, have your brakes checked, those calipers / discs can cause a vibration

 

[Glenn_]

I'm assuming all control arms are tight and not worn, is the sub frame tightened properly to the chassis?

Does the car wander or tramline at all or just vibrate?

Maybe try and get it onto a dyno and see if it is the rear that is a problem or the front, might narrow things down?

Control arms were changed last year, all good on the suspension. It's just the vibration

I'll try to get it on to a dyno and advise

 

[Glenn_]

Sounds ridiculous I know but from experience, have your brakes checked, those calipers / discs can cause a vibration

Changed front discs a year ago, the rest on the braking system I've never replace. I just replace the pads and sensor when doing service.

I will start with the front discs and calipers

 

[Steph745]

Still sounds like a wheel/tyre issue, if it was possible would be nice to fit other wheels and go for a test drive.

 

[Glenn_]

Update!

I think I ruled out the wheel/tyre issue, straightened the rims again and did balancing at Motorvision and it is way better - but it still shakes a bit

They suggested that I take out the propshaft and get it tested(I only did a visual inspection previously), so he demostrated how a guibo can have cracks and I can't see it by just looking, plus the car is on 230k kms

 

[DarrylvanNiekerk]

Glad to hear your are getting somewhere, it would be great to get it fully sorted.

Please update on the progress.

 

[TurboLlew]

If it improved dramatically after balancing then that doesn't rule out the issue being the wheel and tyre - if anything it points to it. Did you try road force balancing at any of these places? Can solve these odd issues sometimes. Guibo isn't a bad idea either way but I wouldn't open the can of worms of rebalancing the prop shaft itself just yet. Same applies to rubbers/bushings around the front suspension that visually might look good but could be in need of changing.