dingodave

Update on my problem: the car spent a couple of days at the dealer earlier this week and they agree it is definitely the rear diff. Apparently they use a noise measuring device taped in the suspected location and confirmed that the noise emanated from the diff. Now the wait until Audi Australia are able to get one on back-order from Germany. A rare occurrence for Australia apparently although they mentioned that it was a known issue in the US.

indyrich

Driving home on the interstate yesterday, I noticed a loud whining noise when decelerating into a service stop/rest area. Same thing when accelerating away. The noise starts about 30 mph and gets progressively louder all the way up to cruising speed at 75. Sounds like when we used to put playing cards in the spokes of our bikes. Car is a '14 Q5 TDI with 52k miles, so, out of warranty. No noticeable heat around tires or wheel wells, no visible signs of a bearing throwing grease, nothing hanging from wheels, etc. Definitely drivetrain related, as revving the motor in neutral doesn't produce the sound. Dreading my visit to the dealer tomorrow.

dingodave

Sadly, I have had the noise reappear gradually over the past twelve months after the first diff replacement.

Different to yours, as again mine is on light trailing throttle or acceleration, most noticeable at very low to low speeds as a brief "growl" on throttle transition, but I think there is also a slight drone at highway speeds.

Booked in for it's 30K service in a fortnight, when I will be pursuing it vigorously. I took it to the dealer back in January, but the service techo couldn't hear anything. (I'm deaf, and I can hear it - go figure!) The replacement diff certainly quietened it for some time, so hoping that it's a case of third time lucky.

indyrich

Dealer said leave it, we'll check it out when we get a chance. In all fairness I did drop in unannounced, but I played the 'I'm afraid it's going to blow up' line and begged him to just spring a mechanic to take a ride around the block. In the end the mechanic took it around the block twice and put it up on the lift as well. The verdict? 'Tires are shot. Replace them and that will take care of your noise'. Well 52k is getting up there for sure but, the wear is even and the tires are not yet down to the wear bars. Plus, it sure feels like a mechanical noise to me, not tire wear. Swerving the car left and right does not diminish the noise, as use to be the case with a failed wheel bearing. I'm reading about all manner of differential problems on the forum, but, my thought is that it would create a noise in the middle of the car and this is definitely coming from the front left.

I'm headed to my indie for a 2nd opinion.

rangmin00

Hey dingodave, did you find out what the problem was? Experiencing the same thing. Thanks!

dingodave

Still to be resolved, although I am certain its a diff-related noise. While it's similar to the original noise, which did disappear for a while after the new diff was fitted at around 15K kms, it has some subtle differences. It will be back to the dealer when I get a chance, for a more intensive check. Last time they had a noise measuring device which confirmed the problem, so I'll be looking for a similar situation on this test. Good luck with your own noise.

dingodave

Hi all : it's been a while so thought I would update on my noisy Q5 TDI. It's still developing in volume, is very brief in duration, and mainly eveident on the transition between light acceleration and trailing throttle. The local dealer has now agreed that there is a noise which needs attention. Car is booked in next week to have a "balance weight" (might not be the exact term used) fitted to the rear diff. Apparently this is a recognised solution to a hum or harmonic vibration observed in some vehicles travelling at a constant speed, and according to the dealer is now a factory fitment from new.

I still have reservations that they have correctly diagnosed the problem, but at least I'm getting some action! Will keep forum posted on the outcome; at least if it hasn't fixed it I will be able to respond back to them immediately!

cjbpersonal

Have a 2014 Q5 TDI with roughly 53K miles. Noticed the exact same droning noise returning from family Thanksgiving. Has been driving me nuts, since other family members don't notice it as much. Very pronounced on highways when coasting/not applying accleration. My first thought was tires, but no indicator light, and pressure is within acceptable range. Noise seems to come from center rear. Not as noticeable during acceleration nor at lower mph speeds. Was thinking about bringing in for service this weekend, and seems like rear diff is the concensus view. Thanks!

dingodave

That's unfortunate. Update on the fix offered for my problem: the balance weight has certainly changed/reduced the noise from the rear end, now almost gone and only a very slight trace is discernible at very low speed, so I'm satisfied with the outcome. I'll nonetheless be keeping a close eye (that should be ear!) on the longer-term performance, but at least I'm enjoying the car again.