Vibration above 70
Discussion
Hi all
I've got a strange vibration issue with my 335i.
Car is fine under 70MPH, once over 70MPH steering wheel will vibrate like the wheels are out of balance, when braking from 70 the vibration becomes much worse.
Wheels have been balanced twice, and alignment done on a hunter machine, all 4 wheels have been checked for buckles, and brakes have been checked.
The tyres on the front are 18 months old Michelin PS4s. This is the only other thing I can think of that is causing this issue. has anybody had a similar issue that has been fixed by replacing front tyres?
All bushes in the car are powerflex poly bushes and are around 2 years old.
Posted this in the BMW forum but didn't get much traction. Any ideas GG?
I've got a strange vibration issue with my 335i.
Car is fine under 70MPH, once over 70MPH steering wheel will vibrate like the wheels are out of balance, when braking from 70 the vibration becomes much worse.
Wheels have been balanced twice, and alignment done on a hunter machine, all 4 wheels have been checked for buckles, and brakes have been checked.
The tyres on the front are 18 months old Michelin PS4s. This is the only other thing I can think of that is causing this issue. has anybody had a similar issue that has been fixed by replacing front tyres?
All bushes in the car are powerflex poly bushes and are around 2 years old.
Posted this in the BMW forum but didn't get much traction. Any ideas GG?
Any flat spots on the tyres? (e.g. from a massive skid or having been parked underinflated or something)
I once had a set of tyres on a Prius where the tyres were quite clearly not 100% round, despite being balanced and relatively new Michelins, as a result there was a noticeable speed related thud/thump. At a certain speed the frequency was such that it created a very noticeable vibration.
Best thing to do would be to swap the wheels from another car and see if it's fine. Alternatively swap front and rear and see if the vibration changes or is felt less through the steering wheel, that'll narrow it down slightly.
I once had a set of tyres on a Prius where the tyres were quite clearly not 100% round, despite being balanced and relatively new Michelins, as a result there was a noticeable speed related thud/thump. At a certain speed the frequency was such that it created a very noticeable vibration.
Best thing to do would be to swap the wheels from another car and see if it's fine. Alternatively swap front and rear and see if the vibration changes or is felt less through the steering wheel, that'll narrow it down slightly.
Jack each corner up, put something heavy and solid on the ground that will sit very close to the tyre and not move so you can use it as a reference point. Rotate the wheel and you should be able to spot if it’s out of round by the small gap you’ve left getting bigger and smaller.
Keep in mind the unsprung weight will sink once it’s back up off the ground. Best to put your reference point at the 3 or 9 o’clock position so try eliminate that. Having someone else rotate the wheel whilst you watch will make any inconsistency easier to spot.
If you don’t see anything with the tyres and wheels, take them off and check the discs with the same method.
Have you noticed any binding of the brakes?
Keep in mind the unsprung weight will sink once it’s back up off the ground. Best to put your reference point at the 3 or 9 o’clock position so try eliminate that. Having someone else rotate the wheel whilst you watch will make any inconsistency easier to spot.
If you don’t see anything with the tyres and wheels, take them off and check the discs with the same method.
Have you noticed any binding of the brakes?
KungFuPanda said:
Don't travel over 70mph?
The issue starts around 65 and happens at 70, annoying for motorway travel and so far I've not found the cause. Tempted to suck up the £200 or so for new tyres and see if this makes a difference. I've seen others say similar issues were due to sticky brakes so may be worth getting those double checkingReciprocating mass said:
If you have discounted everything else I would start looking into the propshaft I’ve had this issue crop up in the past not on a bmw mind, and was only noticeable over 70 mph
A good shout OP; get the guibos and centre bearing checked outI’ve just seen you mentioned the powerflex bushes. I’ve seen people having issues with them falling apart well within 2 years so I wouldn’t completely discount them as being an issues
Edited by Demelitia on Wednesday 26th February 18:31
joe1145 said:
Would propshaft issues manifest itself as vibration through the steering wheel?
No.Out of balance propshaft vibration usually peaks between 40-50 MPH and again with a second harmonic at around double those speeds. It manifests as a light high frequency (approx three times higher than road wheel) vibration felt through the driver and passenger seat and is not load dependent.
If a similar high frequency vibration is load dependent ie, you can turn it on or off with the throttle then the prop may be out of alignment due perhaps to worn joints or Jurid couplings or a failing centre bearing support if the car has them or perhaps loose components in the driveline.
The OP describes vibration over 70 MPH which worsens through the steering under braking. This suggests to me diagnosis starts with investigating front brake disc and road wheel/tyre run out and condition and progressing from there through the action of brake calipers and condition of suspension bushings and joints and shock absorbers.
If all those are found satisfactory then a specialist Roadforce wheel balance where variations in the deflection of the tyre under load are measured would be useful.
Demelitia said:
Reciprocating mass said:
If you have discounted everything else I would start looking into the propshaft I’ve had this issue crop up in the past not on a bmw mind, and was only noticeable over 70 mph
A good shout OP; get the guibos and centre bearing checked outI’ve just seen you mentioned the powerflex bushes. I’ve seen people having issues with them falling apart well within 2 years so I wouldn’t completely discount them as being an issues
Edited by Demelitia on Wednesday 26th February 18:31
joe1145 said:
KungFuPanda said:
Don't travel over 70mph?
The issue starts around 65 and happens at 70, annoying for motorway travel and so far I've not found the cause. Tempted to suck up the £200 or so for new tyres and see if this makes a difference. I've seen others say similar issues were due to sticky brakes so may be worth getting those double checking
t part worns to test?joe1145 said:
The issue starts around 65 and happens at 70, annoying for motorway travel and so far I've not found the cause. Tempted to suck up the £200 or so for new tyres and see if this makes a difference. I've seen others say similar issues were due to sticky brakes so may be worth getting those double checking
You may be able to check for sticky brakes - feel the wheels after you've driven - if one side is noticeably hotter than the other.Pica-Pica said:
Demelitia said:
Reciprocating mass said:
If you have discounted everything else I would start looking into the propshaft I’ve had this issue crop up in the past not on a bmw mind, and was only noticeable over 70 mph
A good shout OP; get the guibos and centre bearing checked outI’ve just seen you mentioned the powerflex bushes. I’ve seen people having issues with them falling apart well within 2 years so I wouldn’t completely discount them as being an issues
Edited by Demelitia on Wednesday 26th February 18:31
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