Strange 'humming' noise - dealer says it's the tyres?
Discussion
Hi all,
I've recently bought a G11 LCI 740d xDrive. While driving, I can hear a faint humming sound, most noticeable from 20mph and upwards. It sounds a bit like you'd imagine a noisy wheel bearing would.
The car is under the AUC warranty and my local dealer have replaced one front wheel bearing and the front differential. No difference.
They've since decided it must be the tyres, Bridgestone Potenza S001's - they tried another set of wheels and tyres, and said there was an improvement (but I haven't experienced that myself).
Could this be some sort of xDrive/Bridgestone issue? There's no way this can be within the tolerance for a BMW flagship car. I had the pre LCI model and it was fine, and all of my other BMW's have been fine.
Would tyre noises become apparent at such a low speed? Anything else worth checking?
I've recently bought a G11 LCI 740d xDrive. While driving, I can hear a faint humming sound, most noticeable from 20mph and upwards. It sounds a bit like you'd imagine a noisy wheel bearing would.
The car is under the AUC warranty and my local dealer have replaced one front wheel bearing and the front differential. No difference.
They've since decided it must be the tyres, Bridgestone Potenza S001's - they tried another set of wheels and tyres, and said there was an improvement (but I haven't experienced that myself).
Could this be some sort of xDrive/Bridgestone issue? There's no way this can be within the tolerance for a BMW flagship car. I had the pre LCI model and it was fine, and all of my other BMW's have been fine.
Would tyre noises become apparent at such a low speed? Anything else worth checking?
Recalcitrant said:
Hi all,
I've recently bought a G11 LCI 740d xDrive. While driving, I can hear a faint humming sound, most noticeable from 20mph and upwards. It sounds a bit like you'd imagine a noisy wheel bearing would.
The car is under the AUC warranty and my local dealer have replaced one front wheel bearing and the front differential. No difference.
They've since decided it must be the tyres, Bridgestone Potenza S001's - they tried another set of wheels and tyres, and said there was an improvement (but I haven't experienced that myself).
Could this be some sort of xDrive/Bridgestone issue? There's no way this can be within the tolerance for a BMW flagship car. I had the pre LCI model and it was fine, and all of my other BMW's have been fine.
Would tyre noises become apparent at such a low speed? Anything else worth checking?
FWIW the F01 730D That I had a few years back came on Bridgestone run flats and they were horrible and droned, a LOTI've recently bought a G11 LCI 740d xDrive. While driving, I can hear a faint humming sound, most noticeable from 20mph and upwards. It sounds a bit like you'd imagine a noisy wheel bearing would.
The car is under the AUC warranty and my local dealer have replaced one front wheel bearing and the front differential. No difference.
They've since decided it must be the tyres, Bridgestone Potenza S001's - they tried another set of wheels and tyres, and said there was an improvement (but I haven't experienced that myself).
Could this be some sort of xDrive/Bridgestone issue? There's no way this can be within the tolerance for a BMW flagship car. I had the pre LCI model and it was fine, and all of my other BMW's have been fine.
Would tyre noises become apparent at such a low speed? Anything else worth checking?
I got a different set of wheels (dropped from 20s to 19s for summer wheels and 18s for winters); fitted Falken FK510 non RFTs to the 19s and zero noise issues; no droning/humming etc and the 18" winter tyres were like 4 balloons
So I can absolutely see how it can be the tyres causing the noise
S001s on my 30d hummed, Turanzas hummed, ContiSport 7s hummed a bit, SottoZero 3s hummed like crazy and my current PS4 Zero Pressures hum a little. They've been the quietest to date. As above, just on certain surfaces and speeds, and also ambient temps it seems.
The HVAC can hum also when it's low on gas/PAG oil, so something else to check. Again, that's only noticeable at low engine revs.
The HVAC can hum also when it's low on gas/PAG oil, so something else to check. Again, that's only noticeable at low engine revs.
rottenegg said:
S001s on my 30d hummed, Turanzas hummed, ContiSport 7s hummed a bit, SottoZero 3s hummed like crazy and my current PS4 Zero Pressures hum a little. They've been the quietest to date. As above, just on certain surfaces and speeds, and also ambient temps it seems.
The HVAC can hum also when it's low on gas/PAG oil, so something else to check. Again, that's only noticeable at low engine revs.
Can you explain ‘ambient temperature’ ? All the external temperature that is experienced at any one time is ambient temperature!The HVAC can hum also when it's low on gas/PAG oil, so something else to check. Again, that's only noticeable at low engine revs.
Recalcitrant said:
The car is under the AUC warranty and my local dealer have replaced one front wheel bearing and the front differential. No difference.
They've since decided it must be the tyres, Bridgestone Potenza S001's - they tried another set of wheels and tyres, and said there was an improvement (but I haven't experienced that myself).
Wow...They've since decided it must be the tyres, Bridgestone Potenza S001's - they tried another set of wheels and tyres, and said there was an improvement (but I haven't experienced that myself).
They replaced a bearing, and the front diff, before ruling out the tyres?
My old e91 used to hum on michelin ps5.
My impreza on yokohama ad08r sound like a wheel bearing has shat it’s self at 50mph then goes away.
I think it’s all about harmonics and certain frequencies produce the hum which you encounter.
My tesla has foam in the tyre to dampen these noises I believe.
I would expect better from a 7 series tbh.
My impreza on yokohama ad08r sound like a wheel bearing has shat it’s self at 50mph then goes away.
I think it’s all about harmonics and certain frequencies produce the hum which you encounter.
My tesla has foam in the tyre to dampen these noises I believe.
I would expect better from a 7 series tbh.
Edited by sam.rog on Saturday 17th August 11:46
My old E53 X5 did this when I bought it many years ago. Had cheapo tyres, negotiated a big discount as I was convinced it was the diff as was the seller when I pointed it out. Turns out it was the tyres. 100% sounded like a whining diff (although your description of humming is a better description perhaps) anything over 40mph. When I put my winter wheels and tyres on the noise went away.
Edited by scz4 on Saturday 17th August 12:00
Recalcitrant said:
Hi all,
I've recently bought a G11 LCI 740d xDrive. While driving, I can hear a faint humming sound, most noticeable from 20mph and upwards. It sounds a bit like you'd imagine a noisy wheel bearing would.
The car is under the AUC warranty and my local dealer have replaced one front wheel bearing and the front differential. No difference.
They've since decided it must be the tyres, Bridgestone Potenza S001's - they tried another set of wheels and tyres, and said there was an improvement (but I haven't experienced that myself).
Could this be some sort of xDrive/Bridgestone issue? There's no way this can be within the tolerance for a BMW flagship car. I had the pre LCI model and it was fine, and all of my other BMW's have been fine.
Would tyre noises become apparent at such a low speed? Anything else worth checking?
I would say it's not the tyres all things being equal (in that the tyres aren't knackered) I had a pre LCI 740d xdrive on the Bridgestones and it was quiet as you'd expect, they're not great tyres but they aren't so bad that they would cause such an issue in my experience, I now have an LCI 730d and they come on Pirelli PZ4 so I'm surprised your LCI still has the Bridgestones fitted, The PZ4 are much better in terms of ride and grip but I can't say I noticed the car being any quieter. I've recently bought a G11 LCI 740d xDrive. While driving, I can hear a faint humming sound, most noticeable from 20mph and upwards. It sounds a bit like you'd imagine a noisy wheel bearing would.
The car is under the AUC warranty and my local dealer have replaced one front wheel bearing and the front differential. No difference.
They've since decided it must be the tyres, Bridgestone Potenza S001's - they tried another set of wheels and tyres, and said there was an improvement (but I haven't experienced that myself).
Could this be some sort of xDrive/Bridgestone issue? There's no way this can be within the tolerance for a BMW flagship car. I had the pre LCI model and it was fine, and all of my other BMW's have been fine.
Would tyre noises become apparent at such a low speed? Anything else worth checking?
One way to test it would be to try differing road surfaces if the specific noise doesn't really change (whilst road roar rises and falls) then I suspect it's not the tyres.
sam.rog said:
My old e93 used to hum on michelin ps5.
My impreza on yokohama ad08r sound like a wheel bearing has shat it’s self at 50mph then goes away.
I think it’s all about harmonics and certain frequencies produce the hum which you encounter.
My tesla has foam in the tyre to dampen these noises I believe.
I would expect better from a 7 series tbh.
The 18" Style 37s I had on my E39 touring were on PS4s and they droned like crazy... First time I did a long distance drive in it I wondered if the heat in Japan had killed the wheel bearings... My impreza on yokohama ad08r sound like a wheel bearing has shat it’s self at 50mph then goes away.
I think it’s all about harmonics and certain frequencies produce the hum which you encounter.
My tesla has foam in the tyre to dampen these noises I believe.
I would expect better from a 7 series tbh.
Sold the 37s though as was offered a silly price for them (E38 37s bored out to fit the E39); put the winter Style 66s on with AVON WV7 winter tyres and they were as quiet as they could be...!
Got another set of 66s and fitted 17" PS4s to them and zero noise... I wondered if it had anything to do with the smaller size and them being a straight set all round rather than staggered
Wills2 said:
I would say it's not the tyres all things being equal (in that the tyres aren't knackered) I had a pre LCI 740d xdrive on the Bridgestones and it was quiet as you'd expect, they're not great tyres but they aren't so bad that they would cause such an issue in my experience, I now have an LCI 730d and they come on Pirelli PZ4 so I'm surprised your LCI still has the Bridgestones fitted, The PZ4 are much better in terms of ride and grip but I can't say I noticed the car being any quieter.
One way to test it would be to try differing road surfaces if the specific noise doesn't really change (whilst road roar rises and falls) then I suspect it's not the tyres.
The tyres are all pretty new, 2 years old, 5mm front, 6mm rear.One way to test it would be to try differing road surfaces if the specific noise doesn't really change (whilst road roar rises and falls) then I suspect it's not the tyres.
My gut feeling is that it’s not the tyres - but it’s so difficult to say. Obviously we’re all describing noises here and that’s a problem in itself. I’d say it almost sounds like a noisy fan bearing (a bit like on some older cars), but it persists even with all the fans turned off, and doesn’t make the noise when not moving.
The obvious thing is to swap to another set of 7 Series wheels and tyres, and I can then drive it and see if there’s a difference, but my local dealer aren’t keen on doing that and are making up excuses - which makes me doubt their opinion that “the noise was about gone when we tried another set of wheels/tyres”…
They don’t think it’s the transfer box making a noise, but could it be? Could it be the other bearing they haven’t changed? It’s tricky.
Soon as you said sounds like a wheel bearing I thought “wonder if the car has Bridgestone S001s.”
Had exactly the same issue on my old golf. Was horrific on that spray tar chipping stuff that had subsequently melted and gone Uber smooth (a lot of it my way)
As soon as some eagle f1s were fitted the noise stopped.
Had exactly the same issue on my old golf. Was horrific on that spray tar chipping stuff that had subsequently melted and gone Uber smooth (a lot of it my way)
As soon as some eagle f1s were fitted the noise stopped.
Pica-Pica said:
rottenegg said:
S001s on my 30d hummed, Turanzas hummed, ContiSport 7s hummed a bit, SottoZero 3s hummed like crazy and my current PS4 Zero Pressures hum a little. They've been the quietest to date. As above, just on certain surfaces and speeds, and also ambient temps it seems.
The HVAC can hum also when it's low on gas/PAG oil, so something else to check. Again, that's only noticeable at low engine revs.
Can you explain ‘ambient temperature’ ? All the external temperature that is experienced at any one time is ambient temperature!The HVAC can hum also when it's low on gas/PAG oil, so something else to check. Again, that's only noticeable at low engine revs.
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