e46 330i Braking Vibration - Any Ideas?

[seang83]

Noticed the other day when braking from 70mph there was a vibration through the steering wheel. It only happens when braking lightly from anything over 50-60 mph. Ive only had new discs and pads fitted within the last 2000 miles. Surely they cant be knackered already can they? Cars a e46 330i cheers for any suggestions

[steve_bmw]

Lollipop bushes on the front arms?
Try jabbing the brake pedal at crawling speed, does the steering wheel kick to one side, this test shows up a badly worn bush, a visual inspection would be best.

[HustleRussell]

Excercise the brakes by using them firmly from highish speed a few times (where safe). This might fix the 'problem'. Failing that I'd be suspecting suspension components, as above. Does the pedal feel normal when the vibration is occurring?

[DVandrews]

I have seen this problem when new disks are fitted, if the new disks are not sitting squarely (debris on the hub face) or the wheel clamp face is not flat and true the disks can distort as the wheels are bolted up. Try measuring the run out on the disk, preferably with the wheel on. The wheel clamp face can often be distorted following wheel refurb.

Dave

[ortontom]

seized caliper

[seang83]

Ok a few suggestions there thanks everyone ive a few things to check then! If it were a seized caliper would i not notice any other problems?

[DVandrews]

Normally a seized caliper will give a shed load of vibration and pulling to the seized side, you will also experience massive overheating of the brakes on the affected side if it is seized on.

Dave

[ortontom]

no my experience has been slight binding - which leads to a hot disc on one side and excessive brake dust on a wheel....it just needs to slightly bind, but with all your describ, and the make and model .......ive been there several times on that type of caliper..

[JRBM5]

Control arms...?

Had the same happen on an old E36 M3 and this was linked back to the control arms....

[seang83]

Right been for a drive there's no pulling to one side, no excessive brake dust, stops really well below 50mph its only when above 50mph that the vibration starts. Ive only had it mot'd a few weeks back and had some bushes replaced. After that there was no advisories. Think im going to take it back and see if they've missed something.

[VinceFox]

My e36 does this. Ive replaced lower arms, bushes, new brakes, new hoses, rebuilt calipers and gone theough 2 sets of discs. I check the disc temp every rime i get out of the car and spin the wheels up to check for free movement. My nsf wobbles at higher speed exactly the same as yours.

I'll be interested to read other people's suggestions for yours, because it sounds like a similar issue.

[drmark]

This contains all you need to know.

http://www.brakeworld.co.uk/brakeworld/buyguide/pd...

[ortontom]

still calipers more than likely, they only need to be slightly binding. Control arms, maybe but you would feel that in other ways too. Are they the original calipers?

ps they wont always pull to one side...

I know of one 330 he had everything done, calipers last and calipers it was....

[ortontom]

its about £260 for a pair of calipers, its not worth ruining the discs ..

europarts

[seang83]

Ok cheers for the help will be having a good look at the weekend with my mechanic. Seriously had enough with this car now I've spent so much money in the last year trying to get it to a good standard and its just one thing after another.

[seang83]

Funnily enough just spoke to him and first thing he mentioned was calipers

[VinceFox]

I'll give you one bit of advice for free, when you put calipers on if theyre used, make sure you put the right caliper back with its original mount/slider bracket. I didnt do this once and they were very, very slightly different shapes. It resulted in the caliper binding when tightened.

[lewis328]

Hello,

I have a 03 330 with similar symptoms, But I have a knocking noise coming from front suspension when at low speeds going over uneven ground cobbles etc. I also have a slight vibration when accelerating from 30-40 mph, and when braking down from 40. My car is in garage at the moment, the garage are going to investigate and get back to me. I am hoping its needing suspension parts replaced and will get the car back tight as a drum. I will update once I get the car back.

cheers

Lewis

[ortontom]

lewis sounds like lower ball joint and or drop links, with sticky caliper too.....its an e46 thing...

[Kawasicki]

It's simple why it happens when you brake. The bushes in your suspension control arms are put under extra load, so they squish a bit. In this squished state they will more clearly pass any vibration occurring due to your wheel/tyre imbalance/uneven roll or due to variations in brake disc thickness (which obviously you won't have as your brakes are new.)

To fix it...

a) check wheel tyre balance again.
If that doesn't fix it..
b) visit a garage with road force measuring kit. They spin the tyre up against a roller and measure how evenly the tyre rolls. The tyres must be just driven on for you to get reliable results.
If that doesn't fit it...it could be a bush in your suspension (as someone else mentioned)...some bushes have a cavity filled with a fluid (hydrobush)..the function of a hydrobush is to dampen vibrations in the suspension...so if yours is shot then the whole suspension/steering system can be likely to vibrate.

Are your discs absolutely new? Fitted recently?