[beardybaer]

Hello all,

Something really odd happened to me the other night when I was travelling along the M25 and I wondered if anyone else had experienced this?

Wednesday evening I was driving to Brussels from my place in SW London. Got on the M25 as I've done hundreds of times before (although not in this car), but going anti-clockwise from about J10 (A3) round to J7 (M23) my car was making a god awful noise, something akin to a circular saw going through wood.

I was travelling between 70 and 80 and the closer you got to 80, the louder it got. I was just about to pull off onto the hard shoulder when I hit a patch of tarmac (most of this section is concrete) and the noise stopped instantly. However, after a couple of hundred meters the concrete started again and the deafening noise started again. Once I got passed this section it didn't happen again on any of the concrete sections between there and Folkestone.

I was wondering if anyone else has experienced this?

I've got F32 430d xDrive, 19" wheels, running the RFT that came as standard, travelling in comfort mode.

I'm new to BMWs (had Golf's with 18" wheels the last few cars) so I was wondering if this was normal?

Oh, and just for info, when I came back from Brussels on Sunday on the opposite side of this stretch of the M25 (also concrete), nothing happened.

[robbiep]

What mileage has it done ? Tyre depths ?
I've always found that when tyres get down to 4mm or so the noise level seems to rocket.

[creepy coupe]

Isn't that the section of M25 where they have cut lots of groves in the concrete in the direction of travel?

[beardybaer]

Originally Posted by robbiep

What mileage has it done ? Tyre depths ?
I've always found that when tyres get down to 4mm or so the noise level seems to rocket.

I've only had the car 2.5 weeks. Just clicked over to 1500 miles, so almost brand new tyres.

[Cherub77]

That section of the M25 is brutal, my car does it too. I'm on bridgestones. Don't worry about it!

[ajfoggy]

Originally Posted by creepy coupe

Isn't that the section of M25 where they have cut lots of groves in the concrete in the direction of travel?

Yep sounds like it to me, truly awful piece of road!

[robbiep]

Originally Posted by creepy coupe

Isn't that the section of M25 where they have cut lots of groves in the concrete in the direction of travel?

I know the section of road, but only ever drive it in a company pool Mondeo when I'm down that way. So never really noticed any particular noise there

If only 1500 miles, then that should rule out tyre wear !

[Quantox]

See post 3, this is normal for that stretch of motorway. You should hear the row that my camper kicks up there.

Q

[beardybaer]

Originally Posted by Cherub77

That section of the M25 is brutal, my car does it too. I'm on bridgestones. Don't worry about it!

Thanks, good to hear it's not just my car.

[beardybaer]

Originally Posted by robbiep

I know the section of road, but only ever drive it in a company pool Mondeo when I'm down that way. So never really noticed any particular noise there

If only 1500 miles, then that should rule out tyre wear !

I've done that section in lots of different cars but never noticed it. It's very odd.

[beardybaer]

Originally Posted by Quantox

See post 3, this is normal for that stretch of motorway. You should hear the row that my camper kicks up there.

Q

Oh normal tyres noise is amplified along there, but this sound was like nothing I've ever heard before. Must admit, it was so loud it forced me to sit at 65/70 for a good 10-15 mins.

[KS_340i]

As others have said, it's normal and due to concrete road. I find 70-75 ok, anything more and the noise resonates really badly. Wasn't as noticeable on my E61 but not great in that either.

[creepy coupe]

Originally Posted by ajfoggy

Yep sounds like it to me, truly awful piece of road!

It's like driving in a third world country along that section. They have done the same thin along a stretch of the M20 (concrete) It must be the oldest section of concrete motorway in the UK

[beardybaer]

Originally Posted by creepy coupe

It's like driving in a third world country along that section. They have done the same thin along a stretch of the M20 (concrete) It must be the oldest section of concrete motorway in the UK

Strange enough it didn't happen on the M20. Just this short section of the M25.

I can't believe in 2016 that we still have concrete motorways. Such an outdated technology

[creepy coupe]

Originally Posted by beardybaer

Strange enough it didn't happen on the M20. Just this short section of the M25.

I can't believe in 2016 that we still have concrete motorways. Such an outdated technology

No it doesn't do it on the M20 in my car. just M25

[GEP77]

The joys of grooved concrete.

And very aggressively grooved as well. Next time you find yourself stationary there (it'll happen sooner or later) open your door and have a look at it.

While changing tyre helps a bit, you'd actually have to go narrower to really reduce the noise. My winters were quieter 225/45 18 all round compared to my staggered MPSS on 19s.

Based on my experience travelling on that section in various different cars, the body style and construction has a very substantial effect as well. Estates being the worst incidentally.

[PurpleTT]

Another vote for "it's normal" I live at j8 and go clockwise every day and up until j10 it's deafening. Does it when I have my non-RFT winter wheels on too. Shocking.

Get your car at 50-55mph on outside lane* around j9 and the steering wheel judders too! Horrid. Hits the resonant frequency of the car I suspect.

*not holding traffic up - I mean when it's congested, i.e. always!

[teaston]

It's the road. There's a random little section of road in Norfolk that does it on mine, on my MPSS's!

[beardybaer]

Thanks everyone. I feel much happier now about the noise, although not happy-happy, just not running back to the dealer shouting 'you sold me a lemon' happy

[HighlandPete]

Concrete can generate some very unusual sounds. I recall a section on the M74 where in one of my cars it sounded as if it was a rhythmic tune. Tyres can whine very loudly, something about concrete where the tyre cavities seem to amplify the sound to a very high level.

[....,,,,..,,..]

Try the M54 it's a nightmare for road noise.

[teaston]

Originally Posted by HighlandPete

Concrete can generate some very unusual sounds. I recall a section on the M74 where in one of my cars it sounded as if it was a rhythmic tune. Tyres can whine very loudly, something about concrete where the tyre cavities seem to amplify the sound to a very high level.

That's what that road in Norfolk does! Haven't tried it with the 335d though yet.