[GW8419]

Hi all,
First time poster but long time lurker! I'm hoping someone might be able to give me some pointers on an irritating noise my 2006 E91 320d is making.

It's on 60k miles and runs lovely from what I can tell. Good power and 50+ mpg. Problem is there's a deep almost rythmic rumble/drone which is especially noticeable when cruising at 70mph in 6th but also at the same revs (approx 1800rpm upwards) in other gears. It's definitely engine related as it disappears when the clutch is in even at 70mph.

I can't hear anything when revving the car in neutral at a standstill but strangely if I rev it up to the same rpm in neutral with the car moving (i.e. experimenting on an empty motorway) the drone/rumble is there. There is a slight vibration which gets worse the faster I go, but only really noticeable above 80mph.

No fault codes on the car at all. No noises or vibrations at all from clutch/dmf but it does occasionally judder when pulling away, mainly when it's cold. My thoughts were dmf but there's no usual symptoms. Maybe flex disc but I've been under and inspected and it looks perfect. I'm at a complete loss now.

Anyone experienced anything similar?

[Roadrebel]

I had a similar noise and vibration, turned out that the inner sidewalls of the cheap Chinese rear tyres had deformed causing the tyres to go out of shape. New tyres sorted it.

[Sensible_]

If it's not making the noise whilst Stationary revving the engine it's got to be wheel related in my opinion.

Smart money being a wheel bearing. Also could be a sticking calliper. I suppose the diff could also produce those symptoms. Or the tyres as previously stated.

For wheel bearing does the sound change in pitch at all when going round corners? Test both directions.

For sticking calliper, take the car for a drive. Get the brakes hot. Then immediately check if one of the brakes is noticeably hotter than the others.

Can you upload a video of the sound?

[GW8419]

Thanks for the suggestions guys.

Unfortunately it's definitely not tyres, definitely engine related as it's related to engine speed rather than road speed. I swapped to my winter wheels and tyres in December and it made no difference.

The noise is very like a worn wheel bearing, but definitely isn't one. Disappears with the clutch in as the revs drop. When free wheeling the car is silent and turning left to right makes no difference. There's also no heat from any wheel after a long motorway drive as I'd thought caliper at one point too. The car rolls very well, no binding at all.

I think I'll try to get a video tonight. It's got me baffled! I keep thinking dmf as the sound is like a worm wheel bearing, I.e. something rotating and out of shape slightly but connected to the engine rather than wheels...

[rasa bmw]

id get all the tensiner pulleys checked for bearing noise

[GW8419]

Originally Posted by rasa bmw

id get all the tensiner pulleys checked for bearing noise

That is a good shout, and something I'll look into. I'd be surprised if it was that as there's nothing when I'm under the bonnet with the revs at the same rpm.

[GW8419]

Does anyone think the DMF could sound like a bad wheel bearing when sitting at certain revs on the move? Only other sign it could be the dmf is that there's a judder when pulling away if it's cold.