Ive got strange vibration in my octavia 3.

2.0 tdi 2016.

This vibration occurs at 80-85 km/h during acceleration with throatle or while rolling. So far ive changed two inner cv joints, gearbox mount, oil in gearbox. My tires are new, wheel been balanced as well. It's not flywheel probably because there are no shakes during turning off or while idling, no sounds either. Any tips? Suggestions?

Is it in the steering (front wheels) or just overall (suggested rear wheels or slightly bent axels).

Maybe wheel slightly out of round, poor Balance or bent Axel, or outer cvs

FWD, tommorow i will try to balance the wheels in other shop than i was before, some other mechanical issues you mentioned woud give other symptoms at any speeds but this one i having trouble between 80-90

I'd start with the basics as suggested - do wheel balancing first.

Swap your wheel wheels to the front and see if it makes any difference to the issue.

Not all tyre fitters know how to balance wheels correctly. I learnt this once when had vibrations through the wheel with some wider 18" wheels following some new tyres being fitted. Despite revisiting various tyre fitters I was told my wheels were balanced perfectly but still the vibrations persisted.

Turned out I needed dynamic wheel balancing to correctly apply weights to the wheels and also aligning so the type colours dots lined up with the valve. A place called 'Protyre' do have balancing machines that have dynamic tyre balancing facilities.

On other cars, older tyres caused me a problem just as you described, presumably developed hard spots as the rubber changes over time.

My wife has something similar on her Hyundai ix20, I think it is due to the power steering motor bushing being destroyed a very common issue on Hyundai's, but could be worth looking at the power steering system as I believe it's electric on the Octavia

Just now, CianKT said:

My wife has something similar on her Hyundai ix20, I think it is due to the power steering motor bushing being destroyed a very common issue on Hyundai's, but could be worth looking at the power steering system as I believe it's electric on the Octavia

But these vibrations are felt underneath the seat mostly not steering wheel or anywhere near it.

53 minutes ago, Crux27 said:

But these vibrations are felt underneath the seat mostly not steering wheel or anywhere near it.

By any chance, is your Octavia a 4x4 version? If so, the cardon shaft balancing weights have a nasty habit of dislodging and causing shaft unbalance.

Other than that....check the exhaust is not rattling in any of its mounts.

Just now, varaderoguy said:

By any chance, is your Octavia a 4x4 version? If so, the cardon shaft balancing weights have a nasty habit of dislodging and causing shaft unbalance.

Other than that....check the exhaust is not rattling in any of its mounts.

No mine has just fwd without 4x4.

Just now, varaderoguy said:

By any chance, is your Octavia a 4x4 version? If so, the cardon shaft balancing weights have a nasty habit of dislodging and causing shaft unbalance.

Other than that....check the exhaust is not rattling in any of its mounts.

Gonna check the exhaust tommorow.