Join Date: May 2015
Location: Ballarat, Australia
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Mysterious driveline noise
So, I have a little problem. A mysterious “wubba wubba” noise coming from somewhere in the front driveline. In fact, there have been several noises, each masking the others. Have managed to track down some of the problems, but this last one is causing both my mechanic and I much head scratching.
Some background: the car (a RHD 2012 2.0l S Line Quattro with 74k kilometres on the clock) was making a faint but growing “wubba wubba” kind of noise from what seemed to be somewhere behind the driver’s side footwell. “Aha”, I thought, “that sounds like a wheel bearing starting to expire”. Which is a bit rubbish - wheel bearings starting to go with 46k miles under the belt seemed a bit soon. Still, the car was due some new tyres, so I thought I’d see how it was after the replacement rubber was fitted.
Post new rubber and full alignment, the “wubba wubba” went to “WUBBA WUBBA” immediately. So, off to the local mechanic for a new wheel bearing.
A quick aside: the local mechanic (and my new best friend!), a guy by the name of Clint Reeder of Motorpro, is a genuine gem. I’d almost given up hope of finding a proper spanner man, knowledgeable on all things Audi, out in regional Victoria, until I found Clint right here, in Ballarat (and only a pleasant 3k stroll away from my place, which is even better). Can’t recommend the guy and his team highly enough.
Replacing one wheel bearing revealed that the other bearing was also on the way out. Yep, shoulda replaced both at the same time, but why would I follow my own advice - always replace wheel bearings, shocks and suspension bushes in pairs - on such things?
Problem solved, right? Err, no. While the noise was vastly diminished, it was still there. Not noticeable when the car is cold, as soon as a little heat gets into the system... wubba wubba. I scratch my head. Clint scratches his head. A “Eureka!” moment (Clint’s, I might add. I was still at the scratching-my-head stage) - it must be the roller bearing on the flanged shaft from the diff to the inner cv joint. Pull down drive shaft, remove flanged shaft, and... Bugger! The roller bearing is fine, feeling as fresh as if it came off the assembly line yesterday.
And that’s kinda where things are at right now. Noise is most noticeable in the 50 - 80kph range, and doesn’t appear until there’s a bit of heat in the system. It may also be present at higher speeds, but unibody construction, all-aluminium suspension and the (in)famous A5 tyre noise makes it hard to tell. There is some small associated vibration seemingly directly under the left foot rest in the footwell, though I wouldn’t swear that was related. Transmission service has been done (not exactly at the 60k mark - ahem - but done), and there’s been no obvious front end issues (certainly while the car has been in my care) that would point to any problem.
So, anybody got any bright ideas, thoughts or suggestions as to possible cause?
2012 (fl) A5 Coupe 2.0 TFSI Quattro S-line, Lava Grey