Weird Noise When accelerating over 50kms

[HarryR]

Hello everybody,Have a Audi A6 sline ultra Automatic 2015,I notice that when the car reaches over 50kms there is a wierd sound like as if it wants to up an other gear,It's very smooth going from 1st to 7th gear but strange noise as if its wants to find a other gear,First I thought it's was tire noise so I changed them all and it's not as noisy now so that made a difference but just can,t figure out what the strange noise is,Had the wheel bearing checked and all fine,Any thoughts much appreciated 

Thanks in advance Harry

[Steve Q]

When was the gearbox oil last changed?

[HarryR]

Hello Steve,

The gearbox was last serviced 20000 kms ago,Would u think that this could be the noise 

[Steve Q]

In that case it shouldn't need servicing. It's worth getting a diagnostic check to see what fault codes flag up. 

[Gojko]

Hello there, did you solve the issue? I got same noise, like you said. Regards

[Gojko]

I replaced pinion bearings, and today new right front wheel bearing. Still the same, tomorrow will change left wheel bearing. After test drive is more coming from the left. 

[Magnet]

Hello Gojko,

Unfortunately Harry, the original poster, joined and last posted a couple of days later in October 2021 and never returned to update the forum on how this panned out, so it’s unlikely that we are now going to benefit from his experience. 
Back to your similar issue Gojko, am I allowed to say you are wasting your money and time by adopting a changing-this-changing-that approach to sourcing the noise culprit here, rather than seeking advice from local (say gearbox) specialists as to where this noise is coming from. 
OK, perhaps a pessimistic and not too helpful a reply ( but aimed at avoiding further unnecessary expense) - it would be very difficult/ almost impossible for anyone on here to diagnose a noise that they cannot hear, on a vehicle they cannot drive or inspect. 
Having said that, indeed someone may respond with a solution to their believed-similar noise, so fingers crossed. 
Maybe a bit cheeky to ask, but perhaps you could keep us updated on the final outcome. 
Kind regards,

Gareth. 

[Gojko]

Thanks for information mate. Just went in the house after replacing left front wheel bearing. Noise is gone! So any one who thinks like I did that bad bearing needs to show play once is up in the air, is wrong.  can be noisy even if everything looks right and tight. 

[Magnet]

Many thanks for the useful update Gojko. 
Wheel bearing issues usually show themselves up when cornering and the additional load affects to bearing on the loaded side - noise changes. 
Great that you have fixed it. 
Kind regards,

Gareth. 
p.s. As a matter of interest, what mileage has it done to need new wheel bearings? 

[Gojko]

I tried that as well, no much difference in cornering. 🤷‍♂️ Mileage is 135k and I believe these bearings are from new, as bolts were so old, struggled to fit spline socket inside. Is visible difference from right bearing to the left one which is bad. Looks like seal gone and grease went out and bearing get dry and noisy. Regards!

Edited July 25 by Gojko

[Magnet]

Many thanks indeed Gojko,

Don’t want to come over as patronising, but you’ve been great, and explained everything for the benefit of others. 

Thank you so much for doing that - you’ve made my day! 

If it were up to me I’d be escalating your membership now to ‘Established Member’. 
Take care, and kind regards,

Gareth.