Vibration above 70

[joe1145]

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?

[joe1145]

I did think this but I have no spare wheels and the rears are wider than the front, so can't swap them around.

[joe1145]

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

[joe1145]

Would propshaft issues manifest itself as vibration through the steering wheel?

[joe1145]

sunbeam alpine said:

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.

I have tried this but one wheel never seems any hotter, however this is usually after driving at lower speeds. I think i need to find a stretch of road that I can do 70 on and pull over from that speed and then check the temperatures.

[joe1145]

Ok so update to this. I have now stopped from 70+ into a layby on a dual carriageway and neither brake was obviously hotter than the other, neither seemed to be overly hot.

This does seem like a balancing issue as its worst around 80, above that it starts to disappear, and below 60 its gone completely.

However, I've never had an out of balance wheel cause shaking when braking, when driving along it is like an imbalance, but when braking the shaking is so much worse.

I'll see if I can borrow some wheels off someone and see if this makes a difference

[joe1145]

I've considered this, perhaps its catching the brake hence the vibration at higher speeds, however i'd expect the brake to heat up. I managed to practically coast from 70 to 0 and I could touch both brake disks with my hand, neither were hot.

[joe1145]

Im sure this is some kind of balance issue as it comes around 65-80 then goes, even if brakes were warped and touching the pad there would be some heat, only other thing perhaps the brake disk is out of balance but that seems highly unlikely to me.

The front tyres are quite worn on the inside so I can justify replacing them