MG4 X Power Vibe/Hum 65to75mph

[CooperS]

So perhaps this problem is indeed smaller than first thought?

Only 15 signature and they have sold hundreds, thousands? of X Powers if my m8s chassis number is anything to go by.

Just in case you haven't seen my post, I drove my friends new to him 6 month old X Power with 3000 miles on the clock and still sporting the Chinese made Bridgestone's.

No vibes and quieter than mine was from new.
I couldn't quite believe it.

But how many know about the petition? However i agree it sounds hit and miss, who has the issue to a greater or lesser extent.

 

[salty]

But how many know about the petition? However i agree it sounds hit and miss, who has the issue to a greater or lesser extent.

Or indeed at all.

 

[jamherber]

As mentioned previously, I spent an hour in Oct 23 registered X-Power demo with 6k on the clock - hardly any vibration (ie if I hadn’t read this forum, I wouldn’t have noticed anything).

On back of this ordered a new one - long story short it’s not far off undriveable between 65 and 70mph. In process of possible rejection.

 

[jamherber]

I sent a link to the petition to my dealer in support of our probable rejection claim coming up.

 

[powerfulx]

I put it down to poor QC, in this small forum the audience is small snippet of those sold. Lots of buyers would think their issue is one off.

 

[salty]

I put it down to poor QC, in this small forum the audience is small snippet of those sold. Lots of buyers would think their issue is one off.

Or don't even think it's a problem at all.

 

[rtenterprises]

My 24 plate xpower has the vibration, but who knows it could have been sat in a factory yard for several months. Petition signed.

 

[jamherber]

My 24 plate xpower has the vibration, but who knows it could have been sat in a factory yard for several months. Petition signed.

Should be a Certificate of Conformity document in the glovebox - this will have a date of manufacture on it. Our 24 plate that we are in the process of rejecting / replacing was built in Sept 23 and had chronic vibrations

 

[siteguru]

If you can't find the CoC, check the QC label underneath the parcel shelf ... the date on that may be fairly close to your car's build date.

 

[rtenterprises]

Thanks it says 11/17/2023

 

[salty]

Thanks it says 11/17/2023

So in theory, yours shouldn't have the vibe. But obviously it does.

 

[Bricktop X PWR]

My 24 plate xpower has the vibration, but who knows it could have been sat in a factory yard for several months. Petition signed.

Check your tyre pressures.
Make sure you have at least 40psi all round.
This has made a huge difference for some members.

 

[OriginalBigAl]

Not sure if the final build date is overly relevant, if there is a slightly unbalanced part in the front drivetrain then that would have been made by batch process, and not all of them by the same 3rd party manufacturer if they have been farmed out. So that could explain why some are affected and others are not, and the dates could overlap. Obviously a balance check is not on the QC list, if indeed that is the problem.

 

[tsedge]

Not sure if the final build date is overly relevant, if there is a slightly unbalanced part in the front drivetrain then that would have been made by batch process, and not all of them by the same 3rd party manufacturer if they have been farmed out. So that could explain why some are affected and others are not, and the dates could overlap. Obviously a balance check is not on the QC list, if indeed that is the problem.

I believe there is also more than one factory, so we can have problems depending on where it was made.

 

[powerfulx]

Check your tyre pressures.
Make sure you have at least 40psi all round.
This has made a huge difference for some members.

Have we worked out the physics of this yet ? My guess is rounder tyre less sidewall , or more transfer of the vibration to the ground ?

 

[Bricktop X PWR]

N

Have we worked out the physics of this yet ? My guess is rounder tyre less sidewall , or more transfer of the vibration to the ground ?

No.


I've been awaiting a 'Learned' member but none has so far materialised with a definitive answer.

 

[powerfulx]

N

No.


I've been awaiting a 'Learned' member but none has so far materialised with a definitive answer.

Me too, another stab would be sidewall flex doesnt allow the vibrations throw more meat left and right. Mmm sounds weird.

 

[nostraduckus]

I owe Bricktop and a few others on here an apology - last night I checked my tyre pressures again. I thought they were around 40psi from when I filled them up a few weeks ago, but they were actually around 37psi. Could be the weather getting cooler? Human error? Who knows. Anyway I pumped them up to 40psi last night and this morning driving to work I was gliding through 100km/h with minimal vibes. Felt like an entirely different car.

Does anyone know if tyre pressure affects driveshaft(half shaft?) or pinion angle? Maybe higher pressure corrects the angle?

Some reading:

Pinion Angle: Witchcraft, Sorcery and The Source of Your Vibration.....? (as related to ICE cars)

Tesla Driveline Vibration issues and fixes. “Aim before firing” - MACSBOOST.com

If you have ever owned a Tesla model S or X of the first generation 2012-2020 you will experience and expensive fix in your future. At some point you will need front half shafts. (CV Joints). The symptom is the front of the car shaking violently under heavy throttle. Typically the car drives fine at

www.macsboost.com

 

[nostraduckus]

I owe Bricktop and a few others on here an apology - last night I checked my tyre pressures again. I thought they were around 40psi from when I filled them up a few weeks ago, but they were actually around 37psi. Could be the weather getting cooler? Human error? Who knows. Anyway I pumped them up to 40psi last night and this morning driving to work I was gliding through 100km/h with minimal vibes. Felt like an entirely different car.

Does anyone know if tyre pressure affects driveshaft(half shaft?) or pinion angle? Maybe higher pressure corrects the angle?

Some reading:

Pinion Angle: Witchcraft, Sorcery and The Source of Your Vibration.....? (as related to ICE cars)

Tesla Driveline Vibration issues and fixes. “Aim before firing” - MACSBOOST.com

If you have ever owned a Tesla model S or X of the first generation 2012-2020 you will experience and expensive fix in your future. At some point you will need front half shafts. (CV Joints). The symptom is the front of the car shaking violently under heavy throttle. Typically the car drives fine at

www.macsboost.com

I had a chat with our AI overlords Meta via WhatsApp. So take it with a grain of salt, but here goes. If anyone knows anyone that could fact check it that would be great!

 

[WibbleWobble]

Just got back from my local MG dealer with my vibrating Xpower. I took there to see if they could do anything about the vibration/throbbing between 58 and 72 MPH that it has had from new. It’s now done about 800 miles. Unsurprisingly there is no simple fix.

Their inspection report was as follows:

“Inspected the vehicle and also another same vehicle and both vehicles have the same vibrations and distortional noise. Suspect it is characteristic of the vehicle”

I noticed they also had one more Xpower in the service area.

They did not know how to fix the problem and said I should contact MG for a solution. I got the impression they were not getting much help from MG UK.

Interestingly they tried rebalancing the front wheels and on the drive home it was a lot worse. This seems to point to a balance issue in wheel/drive train somewhere. If the problem was anywhere other than my usual cruising speed I could live with it, but at 60-70 MPH it’s very irritating.

I have had the car for 28 days so when does the 30 day rejection time run out ? Or does the fact that I have reported it to a dealer stop that clock ?