[djgandy]

Hey all,

Anyone have a good idea what this sound is? It started over a year ago on a trip to Spain, and was present most of the journey. It happens a lot and is fairly easy to trigger with a few methods.

1. Generous throttle on a cold start, essentially putting straight on the drivetrain while its cold.
2. A lap of a roundabout at speed
3. Filling the boot with 60kg of bricks, or load the car up with weight (strain on drivetrain, again)

Clutch down and gearbox in neutral or any gear doesn't change sound. Even turned the engine off once.

Now since most days I just sit in traffic, it's not a huge annoyance to me, but it is something I'd like to get fixed, and something that was meant to be fixed.

BMW actually replaced the diff 2 months ago as they said it was the diff, they even stuck microphones on etc.. Whether they replaced all the auxiliary parts (bearings etc..) I have no idea. I'm guessing they didn't, I didn't see any on the invoice.

What else could it be though? If its not the diff, or diff bearings, surely that only leaves, wheel bearings and drive shaft?

around 30s mark - https://goo.gl/photos/DX5RDYWgmnPg8deb9
from 0s - https://goo.gl/photos/q4mJcJ4xYqTRDRJE6

Thanks
Andy

[old grey steve]

Originally Posted by djgandy

Hey all,

Anyone have a good idea what this sound is? It started over a year ago on a trip to Spain, and was present most of the journey. It happens a lot and is fairly easy to trigger with a few methods.

1. Generous throttle on a cold start, essentially putting straight on the drivetrain while its cold.
2. A lap of a roundabout at speed
3. Filling the boot with 60kg of bricks, or load the car up with weight (strain on drivetrain, again)

Clutch down and gearbox in neutral or any gear doesn't change sound. Even turned the engine off once.

Now since most days I just sit in traffic, it's not a huge annoyance to me, but it is something I'd like to get fixed, and something that was meant to be fixed.

BMW actually replaced the diff 2 months ago as they said it was the diff, they even stuck microphones on etc.. Whether they replaced all the auxiliary parts (bearings etc..) I have no idea. I'm guessing they didn't, I didn't see any on the invoice.

What else could it be though? If its not the diff, or diff bearings, surely that only leaves, wheel bearings and drive shaft?

around 30s mark - https://goo.gl/photos/DX5RDYWgmnPg8deb9
from 0s - https://goo.gl/photos/q4mJcJ4xYqTRDRJE6

Thanks
Andy

Hi Andy

Wished I could of gone out in your car today re the turbo noise you reported but being a)desk boundand b)constantly busy meant I simply wasn't able to do anything.

Re noises, could be a few things some of which you've highlighted. I've even had noise thought to be mechanical cured with would you believe it from tyres or shall I say a change of tyres, I kinda thinking that perhaps since "Spain" you'd of changed your tyres, but if you haven't and they are featherd of slightly miss shapen then yes this can ceate noise. If putting weight in the back aggrevates it then need to understand if its rotational (whether it increases with speed or pitch changes)or static

Interesting that you've repalced the diff, makes me feel that the noise you are reporting is a rotational noise hence the change, listened to the 2 video's first one wasn't that clear second one (your in 4th or 6th gear)sounds drony doesn't it sounds like its travelling too at a guess though these YouTube video's can give you a bum steer but sounded a tad deeper whe you had the phone pointing towards the gear lever areabut I cannot be sure again as there's so much other noise going on, but seen noises before especially ones that travel and you've got to be careful before throwing bits at the car.

But if time allowed I'd of happily shot out with you. If your up this way soon please let me know as that does sound drive train for sure but needs to be heard in the flesh I'd say

[djgandy]

Originally Posted by old grey steve

Hi Andy

Wished I could of gone out in your car today re the turbo noise you reported but being a)desk boundand b)constantly busy meant I simply wasn't able to do anything.

Re noises, could be a few things some of which you've highlighted. I've even had noise thought to be mechanical cured with would you believe it from tyres or shall I say a change of tyres, I kinda thinking that perhaps since "Spain" you'd of changed your tyres, but if you haven't and they are featherd of slightly miss shapen then yes this can ceate noise. If putting weight in the back aggrevates it then need to understand if its rotational (whethher it increases with speed or pitch changes)or static

Interesting that you've repalced the diff, makes me feel that the noise you are reporting is a roetational noise hence the change, listened to the 2 video's first one wasn't that clear second one (your in 4th or 6th gear)sounds drony doesn't it sounds like its travelling too at a guess though these YouTube video's can give you a bum steer but sounded a tad deeper whe you had the phone pointing towards the gear lever areabut I cannot be sure again as there's so much other noise going on, but seen noises before especially ones that travel and you've got to be careful before throwing bits at the car.

But if time allowed I'd of happily shot out with you. If your up this way soon please let me know as that does sound drive train for sure but needs to be heard in the flesh I'd say

Correct Steve, the tyres have been changed since then. The noise is rotational. If I inflate the tyres a lot, the noise is much worse and more likely to happen. Less air in the tyre and less weight in the back doesn't trigger the noise so much. I found a thread describing this exact same thing, saying that the hardness of runflats + high pressures puts a lot of strain on the diff (i'll see if I can find it again)

Thankfully, it's not this bad


I'm going to phone BMW and see if they replaced the diff bearings when they replaced the diff, or whether it was some remanufatured job and they used my old bearings. The noise seems similar to a few I've found

[old grey steve]

Originally Posted by djgandy

Correct Steve, the tyres have been changed since then. The noise is rotational. If I inflate the tyres a lot, the noise is much worse and more likely to happen. Less air in the tyre and less weight in the back doesn't trigger the noise so much. I found a thread describing this exact same thing, saying that the hardness of runflats + high pressures puts a lot of strain on the diff (i'll see if I can find it again)

Thankfully, it's not this bad


I'm going to phone BMW and see if they replaced the diff bearings when they replaced the diff, or whether it was some remanufatured job and they used my old bearings. The noise seems similar to a few I've found

If they've replaced the diff Andy it'll be on exchange i.e. remove old unit replace with new built up unit, things like the front nose cone sleeve and all that should of been removed checked and replaced as required but I doubt TBH this would be the noise you're experiencing from the video as I stated that sounded like it was traveling on the 2nd video you posted

[djgandy]

I'm probably doing about 60mph in the video, some of the noise is the engine. It's the noise in the background that sounds a bit like a washing machine that is the issue. As you can hear though, a lot of the deep noises from the engine are in the video as well.

I'll get a passenger and get a better clip with the rear seats down when i can.

[Aragorn30d]

Certainly sounds like either the diff or the gearbox.

Its changing with power transmission as well as speed. IE you can hear the noise change as you alter the thottle.

[djgandy]

Originally Posted by Aragorn30d

Certainly sounds like either the diff or the gearbox.

Its changing with power transmission as well as speed. IE you can hear the noise change as you alter the thottle.

Noise doesn't change with load per se, it just gets faster as speed increases. Sounds the same in all gears. The noisy drone rumble like sounds are from the engine area.

[Aragorn30d]

doh, i'd clicked that last video and thought it was yours.

Rewatching the original two clips, it sounds like wheel bearings to me.

Drivetrain parts (transmission, diff etc) respond to load, so lifting off the throttle would make a change in noise (like happens in the last clip, you clearly hear the noise disappear as he transitions from accellerating to decellerating then return once the cars slowing down). Yours doesnt, its continuous and related only to speed.

I've had that noise a few times over the years, always wheel bearings. They make a characteristic "wahwahwahwah" noise just like yours is making.

[wallsmk2]

That does sound like a wheel bearing or differential. I've had wheel bearings click, groan, whine, all manner of noises. The last one that went sounded just like this and as it's the easiest and cheapest option, that would be the first place I'd look.

[djgandy]

Originally Posted by wallsmk2

That does sound like a wheel bearing or differential. I've had wheel bearings click, groan, whine, all manner of noises. The last one that went sounded just like this and as it's the easiest and cheapest option, that would be the first place I'd look.

Ok. The BMW tech thought it was the wheel bearing, and it made sense that it was the wheel bearing. When they did more investigation they said that it was the diff. Guess he should have gone with his gut.

[djgandy]

Here's a better video with the sound from the get go. I'm off the throttle the whole time until the end when you can hear a rather burbly engine

https://goo.gl/photos/VB8qTNCHF88bZv7M6

And another https://goo.gl/photos/8AV1qSwJN2w9UEf78

It's going in to BMW next Tuesday for another look. I wonder if I'll be as lucky as that guy who got a whole new transmission

On that burble note, my engine noise in the cabin seems pretty high these days and it really doesn't like to be under 1500rpm at all and makes a right racket from 2000 to 3000 rpm.
This is how it can sound sometimes, I never remember it sounding so unrefined https://goo.gl/photos/8Nj9WAfvZ6n6rkov8

Any thoughts on that? Time for a walnut blast?

[Russbmw]

I'm at work, so cant' listen to the video unfortunately.

I had a whining/droning noise on my e39 some years back, and I'dve bet my bollocks it was a wheel bearing, as it sounded exactly like it - and I've replaced/had them replaced on a number of my cars over the years.

As it happens, I needed new tyres not long after noticing this noise, and with new tyres the sound vanished.

The tyres weren't even down to the wear markers (but were admittedly getting close). From memory they were Continentals.

If your tyres are fairly worn and you have access to another set of wheels, it might be worth trying to rule it out.