Inexplicable weird vibration while doing a pull around 60-80mph?

TPNml · 10-24-2022, 10:02 PM

Hi everyone,

If you ever saw any of my posts regarding oil cooling issues, I switched to Redline 5w30 and had a tech remove the bumper and completely clean the coolers and I haven't had any issues since.

Now I have another (hopefully) unrelated issue where the car will randomly start vibrating (felt through the steering wheel) around 60mph while accelerating hard (>250 lbft torque at engine, regardless of gear) until about 90-100mph when it miraculously goes away. If I cool the car in Sport Plus first the vibration seems to lessen (not sure if the actions actually have a direct relationship or not). There's no vibration when cruising or not accelerating, although there's a slight dull noise when braking if my brakes (Pagid RS29 pads) haven't been warmed up and bedded properly.

I recently had the tires replaced so it's almost certainly not a balance issue. Can someone help me diagnose this?

TopJimmy · 10-25-2022, 05:38 PM

Maybe a wheel bearing? Take off a front wheel and turn the hub in the wheel carrier to feel for anything rubbing or crunchy.

f80fan · 10-26-2022, 10:40 AM

I had vibration through the steering wheel and seat. Tracked it down to a damaged fan blade, chunk missing after the dealer replaced the condenser causing it to be out of balance. Was more prominent in Sport Plus when the fan was running at a higher speed.

krudmunk · 10-26-2022, 11:41 AM

Did you feel this vibration before you swapped tires? Do you have any suspension mods, like lowering springs or coilover? Do you have wheel spacers or stud conversion kit?

If it's vibration through steering wheel, then usually most likely your wheels are not properly balanced. Wheel hub is a possibility too but not sure if this is the case because the maximum amount of vibration is between 60-80 mph and you also mentioned vibration is lessened above 90 mph.

TPNml · 10-31-2022, 11:30 PM

I felt this vibration before I swapped tires, but I can't remember if I felt it before I swapped rims. I have camber plates but no other mods suspension wise.

I will say, I also ocasionally hear small squeals and ticking noises when driving and turning near walls that reflect sound that remind me a little of my Pagid pad squealing noise. Depending on the default pad pressure the rotors might be the source?

Also let me stress, the vibration is only bad UNDER ACCELERATION. Cruising has no issues at all.

When I switch to winters I'll check if the wheel bearings are crunchy or anything. Thanks!

TPNml · 11-01-2022, 10:10 PM

Just beat on the car hard and it didn't go away even after Sport Plus was engaged for a while. I'm starting to think it's a suspension/wheel issue. Gonna get tires rebalanced and runout measured first at Discount tire before trying other things.

TPNml · 11-03-2022, 10:55 PM

Update: I had the tires balanced and it helped but didn't completely fix the vibration. Anyway, I also spun my crank hub (I think, not trolling) so that might have been the cause?

The car is out of commission for a while but I will update when we find out what the cause is.

TopJimmy · 11-04-2022, 09:23 AM

Quote:

Originally Posted by TPNml

Update: I had the tires balanced and it helped but didn't completely fix the vibration. Anyway, I also spun my crank hub (I think, not trolling) so that might have been the cause?

The car is out of commission for a while but I will update when we find out what the cause is.

Damn…

JAI///M3 · 11-04-2022, 03:57 PM

Oh wow, I suppose a loose dampener could cause some vibration…? Or maybe just a bad coincidence. Hopefully the engine just needs to be retimed. If so, count your blessings and get a proper pinned crank hub on it!

TPNml · 11-04-2022, 07:47 PM

The car wouldn't even start after the crank hub spun, and you could hear the air coming out the exhaust in puffs when the starter ran. If the engine needs replacement I'm considering selling the car unfixed outright just due to the financials of the situation - a new engine with a keyed crank hub would be $15k+, and there's no telling what else is ready to break on my car.

TPNml · 11-27-2022, 11:04 PM

Update: got the car back from the shop, problem still there.

TopJimmy · 11-28-2022, 09:03 PM

So no sound we can chase, just the steering wheel vibration?

TPNml · 01-08-2023, 02:15 PM

Update: I changed back to stock rotors and pads that I saved from before I put Pagids on. Over time and more cold driving with the Pagid pads, a ring of hardened spots revealed itself on the rotor as the pad deposits got scraped away by the pads. Looking at the pads post-removal reveals a similar line of glazing on the pad itself as well. With the rotor swap done, the vibration is almost completely gone (as I am sure the old ones weren't completely normal either). Anyway, I'm going to put the vibration to rest... at least until I glaze my rotors/pads again.

theweebabySeamus · 01-08-2023, 09:15 PM

Check your rear diff bushing.

Dabeamerking · 01-10-2023, 02:52 PM

Quote:

Originally Posted by theweebabySeamus

Check your rear diff bushing.

Won’t be bushings. With bushings he would constantly be clunking and feel like jerkiness everytime

theweebabySeamus · 01-10-2023, 03:11 PM

Quote:

Originally Posted by Dabeamerking

Won’t be bushings. With bushings he would constantly be clunking and feel like jerkiness everytime

Not accurate. There have been plenty of weird vibrations under accel that have come from a torn rear bushing, I have experienced it myself. It's part of why they redesigned it in the first palce, for MY2018.

Dabeamerking · 01-10-2023, 03:28 PM

Quote:

Originally Posted by theweebabySeamus

Not accurate. There have been plenty of weird vibrations under accel that have come from a torn rear bushing, I have experienced it myself. It's part of why they redesigned it in the first palce, for MY2018.

Yes obviously but not at a specific speed. The OP figured it was his brake rotors. But diff bushings will make a clunking and jerkiness feeling to it. They never fixed the issue all 2018 did was swap the bushing instead of the rubber but the full solution is to have double rear bushings to eliminate any diff rotation at all

theweebabySeamus · 01-10-2023, 04:11 PM

Quote:

Originally Posted by Dabeamerking

Yes obviously but not at a specific speed. The OP figured it was his brake rotors. But diff bushings will make a clunking and jerkiness feeling to it. They never fixed the issue all 2018 did was swap the bushing instead of the rubber but the full solution is to have double rear bushings to eliminate any diff rotation at all

The specific speeds mentioned could fall within the range for a failed rear diff bushing, as the diag test calls for acceleration in 3rd, 4th, or 5th. I know mine had vibration within that speed range.. Also, vibration under acceleration is a big indicator. Could it be something else, a driveshaft or rear diff? Sure, but saying it's NOT the bushing as an absolute is wrong.

There isn't anything so far indicating that the new bushing design is failing earlier than the original design. Is the dual mount better? Probably, but if the new bushing isn't tearing then I'd consider it fixed.

Dabeamerking · 01-10-2023, 04:26 PM

Quote:

Originally Posted by theweebabySeamus

The specific speeds mentioned could fall within the range for a failed rear diff bushing, as the diag test calls for acceleration in 3rd, 4th, or 5th. I know mine had vibration within that speed range.. Also, vibration under acceleration is a big indicator. Could it be something else, a driveshaft or rear diff? Sure, but saying it's NOT the bushing as an absolute is wrong.

There isn't anything so far indicating that the new bushing design is failing earlier than the original design. Is the dual mount better? Probably, but if the new bushing isn't tearing then I'd consider it fixed.

Diff bushings do not randomly come up at 60 miles per hour and die at 100 miles per hour lmfao. Also stated that Sport + makes the car smoother which is the exact opposite in the case of diff bushings.

TPNml · 01-18-2023, 11:06 PM

The vibration has gotten worse as of late so much that no mode fixes the vibration. It is present in all modes (suspension stiffness, steering effort, DSC on/off/MDM, you name it). I now have access to a jack and stands + friends who work on other german cars so I can diagnose things/check condition on my own now. This weekend I'm going to jack the car up and check all diff bushings. A friend said it might be a front thrust arm bushing so I'm going to check those as well and will report back.

TPNml · 01-24-2023, 06:06 PM

Update: found a crack in the rear diff bushing. I think I'm going to replace all diff bushings with new ones.

TopJimmy · 01-28-2023, 08:46 PM

Quote:

Originally Posted by TPNml

Update: found a crack in the rear diff bushing. I think I'm going to replace all diff bushings with new ones.

Consider doing PowerFlex Purple instead of OEM. They’re slightly stiffer but no extra NVH! I did them front and back.

10-24-2022, 10:02 PM	#1
TPNml Enlisted Member 12 Rep 39 Posts Drives: '15 F83 Join Date: May 2022 Location: DTX -> Indiana iTrader: (0)	Inexplicable weird vibration while doing a pull around 60-80mph? Hi everyone, If you ever saw any of my posts regarding oil cooling issues, I switched to Redline 5w30 and had a tech remove the bumper and completely clean the coolers and I haven't had any issues since. Now I have another (hopefully) unrelated issue where the car will randomly start vibrating (felt through the steering wheel) around 60mph while accelerating hard (>250 lbft torque at engine, regardless of gear) until about 90-100mph when it miraculously goes away. If I cool the car in Sport Plus first the vibration seems to lessen (not sure if the actions actually have a direct relationship or not). There's no vibration when cruising or not accelerating, although there's a slight dull noise when braking if my brakes (Pagid RS29 pads) haven't been warmed up and bedded properly. I recently had the tires replaced so it's almost certainly not a balance issue. Can someone help me diagnose this?
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10-25-2022, 05:38 PM	#2
TopJimmy Major General 5459 Rep 5,152 Posts Drives: 2023 M3 Comp xDrive Join Date: Jul 2019 Location: Chester County, PA iTrader: (5)	Maybe a wheel bearing? Take off a front wheel and turn the hub in the wheel carrier to feel for anything rubbing or crunchy. __________________ '18 F80 Base 6MT \| '19 F82 Exec DCT \| '18 F82 Comp Exec DCT \| '23 G80cx
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10-26-2022, 10:40 AM	#3
f80fan Enlisted Member 15 Rep 48 Posts Drives: F80 Join Date: May 2017 Location: UK iTrader: (0)	I had vibration through the steering wheel and seat. Tracked it down to a damaged fan blade, chunk missing after the dealer replaced the condenser causing it to be out of balance. Was more prominent in Sport Plus when the fan was running at a higher speed.
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10-26-2022, 11:41 AM	#4
krudmunk Captain 343 Rep 824 Posts Drives: F80 M3 Join Date: Apr 2020 Location: San Francisco iTrader: (3)	Did you feel this vibration before you swapped tires? Do you have any suspension mods, like lowering springs or coilover? Do you have wheel spacers or stud conversion kit? If it's vibration through steering wheel, then usually most likely your wheels are not properly balanced. Wheel hub is a possibility too but not sure if this is the case because the maximum amount of vibration is between 60-80 mph and you also mentioned vibration is lessened above 90 mph.
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10-31-2022, 11:30 PM	#5
TPNml Enlisted Member 12 Rep 39 Posts Drives: '15 F83 Join Date: May 2022 Location: DTX -> Indiana iTrader: (0)	I felt this vibration before I swapped tires, but I can't remember if I felt it before I swapped rims. I have camber plates but no other mods suspension wise. I will say, I also ocasionally hear small squeals and ticking noises when driving and turning near walls that reflect sound that remind me a little of my Pagid pad squealing noise. Depending on the default pad pressure the rotors might be the source? Also let me stress, the vibration is only bad UNDER ACCELERATION. Cruising has no issues at all. When I switch to winters I'll check if the wheel bearings are crunchy or anything. Thanks! Last edited by TPNml; 10-31-2022 at 11:49 PM..
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11-01-2022, 10:10 PM	#6
TPNml Enlisted Member 12 Rep 39 Posts Drives: '15 F83 Join Date: May 2022 Location: DTX -> Indiana iTrader: (0)	Just beat on the car hard and it didn't go away even after Sport Plus was engaged for a while. I'm starting to think it's a suspension/wheel issue. Gonna get tires rebalanced and runout measured first at Discount tire before trying other things.
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11-03-2022, 10:55 PM	#7
TPNml Enlisted Member 12 Rep 39 Posts Drives: '15 F83 Join Date: May 2022 Location: DTX -> Indiana iTrader: (0)	Update: I had the tires balanced and it helped but didn't completely fix the vibration. Anyway, I also spun my crank hub (I think, not trolling) so that might have been the cause? The car is out of commission for a while but I will update when we find out what the cause is.
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11-04-2022, 03:57 PM	#9
JAI///M3 Lieutenant 528 Rep 502 Posts Drives: F80 M3 Join Date: Dec 2021 Location: East Bay iTrader: (0) Garage List 2018 F80 [0.00]	Oh wow, I suppose a loose dampener could cause some vibration…? Or maybe just a bad coincidence. Hopefully the engine just needs to be retimed. If so, count your blessings and get a proper pinned crank hub on it!
	Appreciate 0 Quote

11-04-2022, 07:47 PM	#10
TPNml Enlisted Member 12 Rep 39 Posts Drives: '15 F83 Join Date: May 2022 Location: DTX -> Indiana iTrader: (0)	The car wouldn't even start after the crank hub spun, and you could hear the air coming out the exhaust in puffs when the starter ran. If the engine needs replacement I'm considering selling the car unfixed outright just due to the financials of the situation - a new engine with a keyed crank hub would be $15k+, and there's no telling what else is ready to break on my car.
	Appreciate 0 Quote

11-27-2022, 11:04 PM	#11
TPNml Enlisted Member 12 Rep 39 Posts Drives: '15 F83 Join Date: May 2022 Location: DTX -> Indiana iTrader: (0)	Update: got the car back from the shop, problem still there.
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11-28-2022, 09:03 PM	#12
TopJimmy Major General 5459 Rep 5,152 Posts Drives: 2023 M3 Comp xDrive Join Date: Jul 2019 Location: Chester County, PA iTrader: (5)	So no sound we can chase, just the steering wheel vibration? __________________ '18 F80 Base 6MT \| '19 F82 Exec DCT \| '18 F82 Comp Exec DCT \| '23 G80cx
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01-08-2023, 02:15 PM	#13
TPNml Enlisted Member 12 Rep 39 Posts Drives: '15 F83 Join Date: May 2022 Location: DTX -> Indiana iTrader: (0)	Update: I changed back to stock rotors and pads that I saved from before I put Pagids on. Over time and more cold driving with the Pagid pads, a ring of hardened spots revealed itself on the rotor as the pad deposits got scraped away by the pads. Looking at the pads post-removal reveals a similar line of glazing on the pad itself as well. With the rotor swap done, the vibration is almost completely gone (as I am sure the old ones weren't completely normal either). Anyway, I'm going to put the vibration to rest... at least until I glaze my rotors/pads again.
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01-08-2023, 09:15 PM	#14
theweebabySeamus Captain 376 Rep 902 Posts Drives: M3 Join Date: Jul 2014 Location: Bay Area iTrader: (1)	Check your rear diff bushing.
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01-18-2023, 11:06 PM	#20
TPNml Enlisted Member 12 Rep 39 Posts Drives: '15 F83 Join Date: May 2022 Location: DTX -> Indiana iTrader: (0)	The vibration has gotten worse as of late so much that no mode fixes the vibration. It is present in all modes (suspension stiffness, steering effort, DSC on/off/MDM, you name it). I now have access to a jack and stands + friends who work on other german cars so I can diagnose things/check condition on my own now. This weekend I'm going to jack the car up and check all diff bushings. A friend said it might be a front thrust arm bushing so I'm going to check those as well and will report back.
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01-24-2023, 06:06 PM	#21
TPNml Enlisted Member 12 Rep 39 Posts Drives: '15 F83 Join Date: May 2022 Location: DTX -> Indiana iTrader: (0)	Update: found a crack in the rear diff bushing. I think I'm going to replace all diff bushings with new ones.
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