E250CDI vibration at 160km/h and above
I've been driving an e250d from 2009 for a year, the car is in very good technical condition from a mechanical point of view, engine, gearbox, suspension.
it has only one small problem that bothers me and that I would like to eliminate.
at speeds over 160km/h, if I drive it at a constant speed, some small vibrations appear for a fixed duration, say about 3 seconds, after which they disappear and reappear after about the same duration, a more correct description would be: a vibration of a short duration but the same which appears and disappears with the same length as time.
Like a hum that appears and disappears with the same frequency and time
I followed to see if it has anything to do with a certain engine speed.
I specify that the engine has good buffers, the box is the same, overhauls on time, the DPF is clean, the wheels are balanced, I don't use wheel spacers
Thanks

My top speed (that Ive gone accidentally) is like 90mph and funny thing at 85 or above it seems to smooth out (not that its rough at say 70mph).




It was manufacturing "defect" of the tire.
Go and find Hunter wheel balancer with RoadForce capability.
See the left rear at 110Nm, that is way off the chart.
It took me lots pre-check to finally suspect that a new Michelin Pilot Sport 4 could be the fault.
Took months....
New replacement tire , I bought myself.
With all evidence of my other test and roadforce value, I claimed to Michelin Indonesia and I got a new tire from them in approx 30-45 days ( fresh stock )
I then use the tire for the other side. I roadforce balanced it too for sure : Below is the warranty replacement tire.
What is RoadForce balancer ?
I made claim to Michelin Indonesia and they approved.
I am the only one so far claiming replacement based on bad RoadForce value

Good luck............
Last edited by gabrielbecheanu; Sep 24, 2024 at 01:47 PM.




TRANSLATED - Romanian
thank you all for the answer. the wheels are balanced and equally tightened with a torque wrench. The bearings are well adjusted and without wear, so no noise. I am now using some all-season tires bought this year. but a lesser known brand. soon I will change the tires and see if this problem was from the tires. This vibration that I describe is not similar to the vibrations produced by poor quality and unbalanced tires. It is quite difficult for me to describe this problem.
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RoadForce balancing machine can tell you if your tire is bad at certain section. A bad roadforce tire, its vibration is unique its more up-down and not shake left and right.
It is more of a Z axis vibration and not X
Have you actually use a road force balancer ?
It is NOT the same as ordinary balancer.




