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D4 - Common Faults Quick links to all known common faults and their solutions

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Old 4th December 2016, 09:13 PM
Markr Markr is offline
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Default D4 Droning Noise

Hi All,

Thought I would start a new thread, on an issue I had with my last 2012 D4. About 2 years into ownership (c. 35k miles), I got a droning noise at about 65mph+. We went through the usual tyres and bearing checks, and all were given a clean bill of health.

Eventually went into a dealer dictated by Audi UK who had some certain test kit and after some more diagnosis, they determined it was wheels or tyres, so all 5 were replaced under warranty.

Problem went away, but after a little while, it started to come back again. I mentioned the issue to another dealer, and they had the car in and started a period of very indepth diagnosis.

They tried new wheels etc on the car, and what they found was that the problem went away at the speed I noticed, but came back at 76mph+, therefore convinced that it wasn't wheels or tyres - all new tyres did were move the problem.

They did other checks to determine it wasn't engine or gearbox, and on ramp checked everything and found nothing. They got some kit in from Germany that measured external noise, and again nothing pinpointed the issue.

They then got a new A8 on the ramp next to mine and did a thorough front to back check on all moving parts using the new one as a reference. Nothing found, except that there was very slightly more play in the propshaft, but nothing that they would ordinarily pick up as a problem. As a last straw, Audi authorised the replacement, and it fixed the issue and silence was restored. Apparently it was the centre bearing.

It took six weeks to diagnose and get the part, which was on back order for LWB - dealer kept me in a couple of new 8's throughout the period though, so no hardship.

During this time I experienced different wheel sizes, different tyres and matrix headlights - 4 months later I had change to a 2015 D4 with matrix headlights!!

Hope that helps someone else, as it had caused a bit of head scratching.

Cheers
Mark.
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Old 4th December 2016, 09:44 PM
Joe2.0E Joe2.0E is offline
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Wow, thats some service by the Dealer! Good to hear you got sorted in the end.
Thanks for sharing.
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Old 5th December 2016, 12:09 PM
Johnmed Johnmed is offline
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Thanks for sharing OP. You could easily have forgotten to get round to writing the thread starter, and we'd all be poorer for it in the future.

Nice one.
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Old 5th December 2016, 07:48 PM
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I am surprised that Audi hasnt vibration and noise analysis equipment capable of identifying such issues. Ships, submarines and, to an extent, offshore platforms, have used such analysis tools for many years to identify sources of such vibration/noise for reasons of predicting equipment failure and, indeed, self preservation. (Passive sonar tracking systems just LOVE individual vessels with quirky vibes! )
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Old 5th December 2016, 08:04 PM
Lee S Lee S is offline
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Otherwise known as a screwdriver wedged between offending noisy article and the tester's lug 'ole...
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Old 5th December 2016, 08:12 PM
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Quote:
Originally Posted by Lee S View Post
Otherwise known as a screwdriver wedged between offending noisy article and the tester's lug 'ole...
They did move on to somethings slightly more sophisticated (Fast Fourier Transform analysis was involved ) but the screwdriver technique is something I can understand and have employed on various cars I have owned.
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Old 6th December 2016, 12:06 AM
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What do you reckon to the Matrix LED's as opposed to the standard (HID?) headlights?
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Old 6th December 2016, 07:01 AM
Markr Markr is offline
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The matrix beam LED are absolutely brilliant. You can be on full beam all the time and it will black out thoose things coming towards you, but keep full beam around them. Very different to just adaptive lights I had before, which are either fully on or fully off. When you go into a built up area with street lights it turns itself off, so assume it can only cope with so many lights coming towards the car at any one time.

I used to get flashed with the adaptive lights, but as yet never have been with matrix.

Cheers
Mark
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Old 6th December 2016, 06:45 PM
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Good to know that it was the propshaft bearing causing the drone at the end. I have a slight drone which increases dramatically on rough surface - e.g M25 junction 9
I guessed tyres, will soon change them, if it doesnt help will check the centre bearing.
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Old 6th December 2016, 09:25 PM
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I have found that different brands of tyre have a marked difference on the noise level and mpg. I have been recording every fill up for nearly 4 years by tyre type.

Of the Pirelli, Michelin and Goodyear tried over both D4's, th Goodyear are by far the quietest, both in 19 and 20 form. Pirelli is best on mpg and Goodyear the worst.

Michelin Pilot Sport were the loudest and Pirelli somwhere between the two.

Goodyear are the set I preferred.

Has anyone tried Continental ContiSilent tyres - the ones with the foam in?
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