[stoneba7]

Long time reader, first time poster. I have a 2020 540xi and have been trying to get to the bottom of a vibration that manifests around 70 mph and gets worse with increased speed.

I’ve read this very helpful thread, and am looking for advice on how to approach a diagnostic appointment at the dealer this coming Friday: https://g30.bimmerpost.com/forums/sh....php?t=1981578

Guibo was replaced under warranty. I noticed the vibration after this service, and brought the car back to be checked. The dealer didn’t find an issue with the new guibo, but did find two wheels with slight bends and uneven tire wear caused by this. Since then I have had the wheels straightened, installed four new tires, and had an alignment. Two dealers and Tire Rack found no issues with the wheels and the tires road force balanced without issue.

So, I’m trying to determine the most likely cause of the vibration. It is very minor, a “whomp whomp” that I feel through the whole car rather than a specific corner or in the steering.

Based on the other thread, my current thoughts, in decreasing order of likelihood, are:

1) New guibo is bad, or driveshaft imbalance

2) Out of balance brake rotor(s) (though I have no other brake related symptoms)

3) Out of balance half shaft(s)

4) Motor mount(s)

5) Bigger issue, such as bad differential.

I can’t think of any other rotating components, but am I missing something? Does this seem like the right list to check? Are there any tests I can do myself in the next week to try to eliminate possibilities and steer the dealer to the most likely culprit?

I appreciate any advice!

[HerkHealer]

What tires are you running ?
I had a problem with my ex's car and went through all kinds of hell trying to figure the vibrations out. Even after road force balancing, etc.
In the end, it was the tires. Swapped them out with a good set of Michelins. and fixed it.

[stoneba7]

Originally Posted by HerkHealer

What tires are you running ?
I had a problem with my ex's car and went through all kinds of hell trying to figure the vibrations out. Even after road force balancing, etc.
In the end, it was the tires. Swapped them out with a good set of Michelins. and fixed it.

I replaced the stock Continental ProContact GX SSR with Michelin Pilot Sport AS4. The new tires went on this past week.

[HerkHealer]

I'm assuming you replaced the tires after the Guibo was done at the dealership.
And you still felt the vibrations. Which, to me, says the dealer replacement "might" be causing the vibration.
However, there are many variables you're not giving here (new tires).
Please be more specific. When did you install the new tires, etc.

[stoneba7]

Originally Posted by HerkHealer

I'm assuming you replaced the tires after the Guibo was done at the dealership.
And you still felt the vibrations. Which, to me, says the dealer replacement "might" be causing the vibration.
However, there are many variables you're not giving here (new tires).
Please be more specific. When did you install the new tires, etc.

The timeline is somewhat stretched out because of a busy schedule, but here’s the order:

Guibo replaced
Wheels straightened
[gap during which vibration persisted]
This past week both alignment and new tires.

I was definitely experiencing multiple sources of vibration, since straightening the wheels and replacing the tires both led to improvements, but the symptoms described above remain as of today.

[HerkHealer]

Originally Posted by stoneba7

The timeline is somewhat stretched out because of a busy schedule, but here’s the order:

Guibo replaced
Wheels straightened
[gap during which vibration persisted]
This past week both alignment and new tires.

I was definitely experiencing multiple sources of vibration, since straightening the wheels and replacing the tires both led to improvements, but the symptoms described above remain as of today.

Since you've done all of that, and the vibration still continues, I would go back to the dealer and give them this information. You're still experiencing the same vibration. Ask them to look at axles, and other driveline components.

[BMW012]

are you the first owner of the vehicle? was the vibration always there? is this your first car with run flat tires?

[iamcc88]

Commenting to add that I am in a nearly identical situation with my 2021 M550.

I had no noticeable vibration at any speed… my Indy recommended the guibo replacement so I took it to dealer for that.

2 days later, new Michelin PS4s go on and ever since then I’ve had vibrations above 80mph or so

Been too busy to really deal with it and I kept telling myself they just balanced my new tires wrong so I’ve been planning to go back for that.

[stoneba7]

Originally Posted by BMW012

are you the first owner of the vehicle? was the vibration always there? is this your first car with run flat tires?

No, I bought the car CPO. It had no vibrations when I bought it. I didn’t notice the issue until after the guibo was replaced. It is not my first car with RFT. Before this I had a 330xi I bought new. When the 330’s RFT wore out I replaced them with non-RFT Michelin PilotSport AS4s. I just put the same non-RFT Michelins on the 540 last week.

[ezaircon4jc]

Wild idea... Are the guibo bolts balanced?

[BMW012]

im assuming everyone is getting the non star marked ones?

granted I have no idea if thats causing the vibrations or not.

[stoneba7]

Originally Posted by ezaircon4jc

Wild idea... Are the guibo bolts balanced?

I suppose theoretically bolts of different weights could be a cause of imbalance. I will ask about it at my appointment.

[ezaircon4jc]

Originally Posted by stoneba7

I suppose theoretically bolts of different weights could be a cause of imbalance. I will ask about it at my appointment.

I had to have the rear pinion seal replaced on my Lincoln LS and the driveshaft was very similar to the BMW's setup. The bolts that connected the driveshaft to Lincoln's version of the guibo were balanced and had to be installed in the same location from where they were removed.

Just a thought.......