Dealers/Importer doesn't find an issue, car shakes and noises coming

You seem to speak English well enough. Everyone in The Netherlands speaks English according to my Faterh in Law, He worked for Unilever and travelled enough to Holland to know.

Agreed

However . . . perhaps not all Dutch mechanics speak ā€œtechnicalā€ English as well as we do

I have had car mechanics they didnā€™t speak English at all in Netherlands.
And explaining noises and feeling can be difficult if you are not native.

The most disturbing is how Dealers workā€¦ Awful experience (never had it before).

The problem is not fixed and gets worst.

Well, it all depends, I suppose

When it comes time to choose their mandatory foreign language(s) in school, many/most choose English, but some donā€™t

todayā€™s ride was bumpy.

not much shakin gon accelaration/coastingā€¦ but then it started!
now i had also a strange shuddering whenever i brake tooā€¦ but only on that sweet spot.
stopped and touched the wheels! i would touch the rims with no probsā€¦

can wheel bearing cause this shaking on long use?

Did someone measure the brake rotors for runout. I bet its a high spot on the rotor causing a vibration at high speed. Are these aftermarket rotors or OEM?

the brakes are new (500km) and the previous was changed for similar issues!
so no it is not the rotors!

And it doesnā€™t do it always.

the worst it was not a wooble on steering but a strange shuddering (like a massage machine)

while it was braking also a sound was coming like a moaning. scary one.

Brakes are not the problem

ABS brakes usually make strange sounds and pulsating when you brake hard.

It was not hard braking! no brakes locked. I know how abs works

I was trying to brake softly from 140km/h - 120km/h in 3-4 seconds
it was more like a loud noise like grinding with vibration no steering wooble. like 10 times faster than a typical woobleā€¦ it was like a massage machine.

if the disks wrapped in 500km (~300 miles) from new, for sure something else is wrong

Time to replace vehicle . It is not worth this amount of frustration.

Thank you for the advice, I passed this stageā€¦ one two extra checks and then time for replacement.

I heard that advice before. It is the easy one i could say.

So what typically causes:

intermittent shimmy at accelaration AND
after long rides shimmy at braking too?

The rotors could still have a measurable run-out even though they are newly replaced. Bent hub, wheel bearing problem for example. Checking rotor run-out is a simple and quick job. All thatā€™s required to do to the car is to remove the wheel. Might as well check the tire for out of round run-out too. Thatā€™s probably where Iā€™d start if I had that problem.

Given what you say youā€™ve already had done though, I think youā€™re probably going to need to bring in an Alfa expert to solve it at this point. Years ago I had a problem with an industrial electronic instrumentation box the size of a fridge that was intermittent. It took 3 engineers working 8 yours a day for an entire week to find the problem, a small piece of wire about 2 mm long had worked its way underneath a connector and was invisibly bridging two pins.

The problem is here there is no such a mechanic (anymore). Alfa itself cannot diagnose it.

I suspect the disks where damaged or just showing side effect signs. because the previous disks had similar behaviour.
Can it be that the shaking caused (due to braking at that speeds) the disks to make these hot spots? and lead them to going crazy?

Also what makes me think that it is not the disks

  1. It happens randomly (especially if I havenā€™t used the brakes)
  2. One time it happened during the day, use the car 6 hours after that day in the afternoon (even at smaller speeds like 50km/h braking). Parked car next morning all perfect until it was used for some time.
  3. There is a huge cabin shaking with a tickover shimmy (like every second). IF during this issue which lets say the rotors has problem, I do 2-3 stops hard ones, the problem dissapears or at least reduces

That makes me think it might not be the rotors. and that makes me think most of Bearing/Hub issue

Itā€™s very easy for a mechanic o measure runout using a dial indicator

I would imagine somebody in the shop should have such a tool

Honestly, I was surprised that the shop didnā€™t have the ā€œchassis earsā€ tools . . . it only makes their job easier. But perhaps theyā€™re not used to dealing with these kind of complaints?

Replace your axles.

although the brakes are shaking the car!!! but only sometimes (it leads to other vibrations)
also most of the times i have only accelaration shaking at high speedsā€¦

I think it is the axlesā€¦ I have also now an strange click noise, but a bit, at low speeds when i press the gas, during the transition moment.

if the rotors where problematic, should they vibrate Sometimes? or long driving without braking (for instance)ā€¦ no!

should they stop vibrating if you use them a bit more aggressive? (make them hotter)? i believe not!