WetinOregon

I've had my A4 for a little over a month now and have noticed a vibration at around 28-32 mph. It typically occurs in the morning when the car is cold, but I can feel it coming on as I accelerate through to 40 mph or so on my way to work. It feels like there is a roughening of the axles or transmission. The vibration disappears at around 32-34 mph.

Is this normal for Audis before they warm up? I've spent the last decade or so in Acuras, so this sensation is new to me.

Thanks.

up-n-coming

The ABS system self tests itself at 26 mph. Is the vibration you mention in addition to the ABS self test? If your accelerating slowly when you feel the vibration and immediately look at the speedometer you'll see it's 26 mph. If your accelerating briskly and look down at the speedometer then you'll see somewhere between 28-30 mph.

I have a feeling what your experiencing is the ABS. Too much of a coincidence imo but maybe not.

WetinOregon

Thanks UpN, but I don't think it's the ABS. That seems to occur at very low speeds - below 5 mph. This vibration is much higher - 28-32 mph. It's almost like the driveshaft is vibrating.

twlai

what was your RPM during the vibration?
i see the same issue when RPM is low during acceleration.

up-n-coming

Ok, maybe your vibration is unrelated to mine. Pretty sure mine is normal. Pretty sure there's a thread about it here on AW. Couldn't find the thread though.

Here's another thread from a AZ. Clicking when car reaches 40 kph

WetinOregon

I don't know what the RPM was, but that's a good question. I'll take a look tonight on the drive home.

VM

In the B9, something to do with the ABS/brake system does something when you first go over 40km/h (26mph) in a drive cycle. It's been discussed endlessly on forums, and everybody's car does it...

VipinLJ

It can happen when the rpm is low/car is in a higher gear than normal. Same happens in my A4 and A7 and used to happen in my A6 too. I'm used to it so it doesn't bother me.

WetinOregon

Ok, I paid a lot more attention to this last night and this morning. And yes, VM, "something" does happen, but it's not ABS related.

The vibration occurs at low RPMs - like Vipin suggested, typically around 1250 and when the car is in a higher gear. After manipulating my speed and transmission, I narrowed it down to a simple explanation: it's just the transmission bogging down a little in too high a gear. I found the sensation appeared at different speeds, but the common denominators were twofold: (1) RPM in the 1200-1300 range; and (2) immediately following an upshift.

Using the paddle shifter to drop down a gear eliminated the problem.

Thanks to all who provided helpful input in steering me toward an answer. Much appreciated.

VipinLJ

Yup. That's absolutely normal. Happened to me yesterday while my car was doing 1200rpm in D7 and I accelerated slowly. Happens more in the 3.0tfsi. But it's something I'm used to. Just physics working the way it should. Unless the vibrations rattle your mirrors and doors to an extent that it becomes unbearable in which case you'll need to check the engine mounts and stuff.