03-09-2024, 10:12 PM | #1 |
Rory
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Is your M60i vibrating and lumpy at braking between 45mph and 25mph?
M60i owners please let me know if you're also noticing what I can best describe as a subtle drivetrain vibration followed by also subtle but chunky/rough/uneven braking when easily slowing down.
It happens consistently when slowing through 45 and 25mph. Before and after these speeds braking is completely normal. Braking moderately hard kind of hides the feeling and it's much more noticeable in normal gentle and easy driving conditions. I have also found that if I change the gearbox to (N) neutral, the braking is perfectly smooth as expected. I suspect the above behavior has something to do with the mild hybrid system playing a role in braking but I can't be sure? Have a look at this review by Throttle House comparing the X7 with the GLS and Range Rover - the guys talk about what seems to be the same thing on the X7 M60i as well. I'm curious if others are experiencing this and if it's something that can be (or has been?) corrected through a software/firmware update or hardware replacement? My M60i only just passed 4000 miles and this isn't a new behavior - it's been a characteristic of the day from day 1 but it just doesn't feel right - I've owned BMWs for 20+ years. Appreciate any shared experiences or advice here. Thanks. Watch this X7 review from 8:00 into the video: https://www.youtube.com/watch?v=vuUaXXNgZFI&t=470s Last edited by roryhw; 03-09-2024 at 10:40 PM.. |
03-10-2024, 09:31 AM | #2 |
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Drives: 2024 X5 M60i
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I do not experience anything like that in my M60i.
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Current - 2024 G05 X5 ///M60i in Java Green Past - 2005 E53 X5 3.0i in Titanium Silver; 2008 E92 335i in Montego Blue; 2019 G01 X3 M40i in Glacier Silver; 2022 G80 M3 Competition in Twilight Purple |
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roryhw36.00 |
03-15-2024, 09:09 PM | #5 |
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I have noticed this on my 24 X7 M60i. I have about 2k miles on it now and I noticed it almost immediately after picking it up. The vibration is definitely subtle with slight differences depending on the rate of slow down. The brake pedal feels a little weird too during that time. I will say as a passenger you don’t notice it much at all. I am surprised by it though. Surely has something to do with the mild hybrid/regen.
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03-15-2024, 11:40 PM | #6 | |
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I have decided to get the dealership to look at it. Booked for early April. I’ll share an update after. |
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03-16-2024, 08:40 AM | #7 |
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Yes, I have tried braking in neutral. It is smooth as I would expect. The vibration seems to happen when the car is slowing and downshifting as necessary (as late as possible for fuel economy) between 45-25.
Additionally, when im in sport mode/using the paddles I don’t feel the vibration issue (brakes can still feel weird). I assume this is because the car/me is downshifting earlier so the car stays higher in the revs. From what I’ve experienced so far I think it has to do the mild hybrid motor “assisting” with the minor downshifts. When normally slowing, instead of injecting a little extra fuel into the engine to downshift from say 4 to 3 gear (1000 to 1250ish RPM), the car uses torque from the electric motor to spin up the engine to the desired RPM for the downshift. When slowing the 6-5-4-3-2 gear changes occur pretty quickly one after another. This is constantly sending spurts of torque to the engine without the engine being under load as it would be in a car without mild hybrid. This is what I’m pretty sure is causing the drivetrain vibration at those speeds. I could be wrong but after analyzing this issue for a while I can’t come up with anything else. I will also try to get my car to the dealer to see if they know anything about it. Will keep updated. |
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roryhw36.00 |
04-02-2024, 04:46 PM | #8 |
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I wouldn't call it a vibration
I wouldn't call it a vibration, but I certainly feel my 24 M60 brakes differently than a non hybrid car. I haven't tried the neutral trick, but the brakes feel a bit off. I find it happens at slower speeds.
I also notice if I drive in Eco mode I get a lot of engine braking in certain circumstances. It doesn't really bother me...but it feels different for sure.
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roryhw36.00 |
04-03-2024, 11:02 PM | #9 |
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Update following a dealer visit:
The dealership service foreman inspected my vehicle with the BMW area engineer who was at the dealership. Following a test drive the area engineer did not find any abnormality in the braking operation. The sensation during braking operation is apparently a characteristic of the mild hybrid drivetrain and the feeling I reported does not constitute a defect. No repairs or corrective measures are required. So… it’s good to know there is no defect and I guess I just have to get used to the different feeling of the M60i mild hybrid helping braking while slowing at low speeds. |
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04-05-2024, 08:50 PM | #10 |
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I have the same going on in my ‘24 50e.
I also had the dealer look at it when I took it in and it came back as normal and it’s the regenerative breaking doing its ‘thing’. I assumed as much, but I am surprised that there is that mild shutter regardless… must be some type of harmonic interaction at that speed causing it. Other than that small speed range affecting it, it’s smooth as butter at all other speeds. |
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04-05-2024, 10:38 PM | #11 | |
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So far we know X7 M60i, X5 M60i and X5 50e are all doing this. Still don’t love it but slowing getting used to it. |
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05-05-2024, 02:58 PM | #12 |
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Hi all -
Coming here to say that I'm experiencing the exact same thing on my brand new (less than 400 miles) 2025 X5 xdrive40i. Has been happening since the moment I left the lot. It's only noticeable in comfort mode - in sport mode the downshifts are quick and smooth without any vibration. In comfort mode, I find the vibrations to be most noticeable in the seat of my pants when braking between 35 and 15 mph, though often strongest between 18 and 25 mph. When the car downshifts, the lumpy juddery vibration can be felt in the seat. I find it to be extremely annoying. I also believe it's coming from the mild hybrid system. What is frustrating is that the demo X5 I drove before purchasing mine did not exhibit this behavior at all - so I know it's possible to have one of these vehicles that is silky smooth across the whole range regardless of driving mode. I was reading somewhere that the MHEV generator has its own set of belt tensioners and the generator itself has its own internal weights for balancing the motor. I wonder of some of our vehicles have improper tensioner settings or the internal weighting is off, which would lead to this behavior. That said, we'd be hard pressed to get the dealer to check the tensioner on these systems as I'm sure even they barely know how this stuff works and likely don't want to muck around with it. Frustrating on an 80k vehicle, especially when there are copies floating around there without the problem. I might schedule a visit with the dealer and ask them to check MHEV generator tensioner to see if any adjustments can be made which could lead to an improvement of this condition. Edit: I should note that I've tried the neutral trick and the car brakes silky smooth with no vibration at all as expected. Hopefully we can collectively find a solution to this. Last edited by bgconley; 05-05-2024 at 03:03 PM.. Reason: Additional info added |
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roryhw36.00 |
05-05-2024, 03:12 PM | #13 |
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There also appears to exist a whole host of vibration damping components related to the MHEV system. I'm trying to dig up a more detailed mechanical schematic but this is the best I can find at present. It's on a page to buy the actual vibration damper for the MHEV.
https://www.bmwpartsnow.com/oem-part...er-11239845162 |
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