DRC noise under normal operation

[rspj]

Mine only does it on driver side also like wise only do it on sharp bumps not on passenger side it must be a problem

[Hitman70]

Hi,

Sorry to bump this old thread, but I found it looking in google for my problem and the OP describes exactly what i hear in my car ""the noise sounds like someone is dropping a cricket ball on a piece of plywood"

My car is a 2016 RS6, with DRC, I just bought it with 48'000 km on the clock, and when I drive over certain bumps, I got this sound, like a deep "gnock gnock" coming from the passenger area. Like the OP said, it doesn't seems it's coming from any one corner of the car, in my case, looks more it's coming from the B pillar in the passenger area.

The sounds don't occurs on every bump, and the size of the bump doesn't matter too: some big bumps don't do the noise, and some smaller do it. But, if I drive 5 times over a bump that did it, it will do it 5x, so a "noisy bump" will remain as it everyday. Maybe it's not the size of the bump that makes the noise, but more the angle of this bump. I also noticed that the bumps that are in a curve seems to do more noise than the others.

Is it the DRC noise?

And, as some people said, often the dealer wasn't able to fix it, and my dealer already told me he hear nothing and that all is OK after having inspected my suspension, I wonder if some of you chosed to live with it and to let it without trying to fix it, as fix seems almost impossible to. And in this case, did it get worse over time? Because I'll probably just do nothing if it's safe...

Thanks for your feedback

[RS4GCI]

Hi,

I experienced the same when I picked up my RS4 from an independent garage. I did a lot of research on the topic before I bought my RS4 so had a good idea what I was getting myself into.

I’m assuming your RS has DRC suspension, if so it will be that your system has lost pressure and will need to be drained and re-pressurised. This will cost anywhere in the region of £350-500 depending on where you take it. There are a few independents that can do this job, MRC in Oxford is a good bet, otherwise it’s an Audi dealer as the kit to re-pressurise the system is specialist equipment.

When I had mine re-pressurised two corners were almost down to zero pressure so I’m fairly confident this will be your issue. Over time the system seems to lose pressure and owners have to get it re-pressurised down the line.

Mine felt a lot better on the road once it was done. A more stable ride.

There is also an inherent issue with original shock absorbers on the DRC system, I won’t detail that here as there are other threads that cover it but basically the noise may never fully go away it just gets faint and will only occur under very specific road imperfections.

Re-pressurising the DRC would be my first option.

Steve

[Hitman70]

Hi,

Thanks for your answer.

So my dealer told me my car is OK, all has been verified before sale and it's not necessary to adjust the pressure in the suspension...

So maybe it's the 2nd option, and the noise is just coming from the shock and that could be a normal, inherent issue...

The noise is really randoom and not so frequent, not all bumps do it, often, even large bumps doesn't do it. Only specific bumps make the car do the noise, usually it's the bumps located in a curve, in a roundabout or in an inclined road that do it. And the noise is really a "woody" "knock knock" noise like a wood ball hitting something, it's coming from the left side of the vehicle, so passenger size in my country, but not from a corner, more like the B pillar, and it's loud and resonating in all the car.

[RossDagley]

That very much sounds like DRC. The central valve is located under the rear seat area (under the floor) and when it has lower pressure sounds exactly like you describe. A wooden knock knock rapid but short noise.
I’d wager they didn’t check the drc system pressure before setting the car at all and are now paying you lip service.

Have it checked.

[Hitman70]

Thanks for your answer.

I called them and they insisted that all is OK with my car and they can't look at it until August because they are overbooked due to the post Covid19 situation... So... Nvm... I'm an accountant not a mechanic, I'm not supposed to know this and to know their job, I paid a lot for this car for have only fun and a good driving experience, not for bother about this... So I have a warranty after all, so we will see...

[RossDagley]

Well as long as it’s noted on your cars file with Audi you’ve complained about it now, if you do visit the dealer in August you have a case that it’s been “going on for several months now”

[Hitman70]

There is so many threads about DRC, but I couldn't find any video of the noise.

The best I found is the description on this thread stating it's a "woody noise like a cricket ball falling on the floor", and it's the noise I have, but I wonder if someone managed to record it and if there is a video I can find somewhere for compare with my noise? Just for be sure I have the DRC noise and nothing else...

Ofc you could ask why I don't do it myself, instead of asking for it, but the noise is so randoom, I could record 1h of driving without it happens and then I hear it 5 times in 3 minutes... Seems it's more on bumps that are located in a curve or in a roundabout than in bumps in a straight flat road. It's small bumps "irregularities" of the road that do it, not large bumps like speed bumps that will never do it.

[RS4GCI]

From what you have described on your posts, I’m certain it is DRC, mine behaved exactly as you described with a Woody type knock noise only on certain bumps or imperfections in the road, it was quite random.

You need to get your pressures checked on the DRC. That has to be the starting point. That’s where I started and sure enough I had low or almost no pressure on each shock absorber.

[skirs6]

Reading this thread brings back memories of my previous Audis all with suspension knocks for various reasons all three RS6’s C5 C6 C7 then I went RS3 no issues even on mag ride, Then the R8 again on mag ride both no issues. Last week I bought a 2014 RS4 and yes you guessed it suspension knocking.

[Outtlaw]

Good luck on getting the DRC sorted

[Rugslasher]

Got this myself after only 1200 miles since having DRC re-pressurised due to burst pipe , there’s no leaks or anything anywhere so wondering if they’ve not done right or if it can mess up due to not using car during lockdown

[RS4GCI]

The knocking noise appears to be an inherent behaviour of the original DRC shocks when in comfort mode. They have developed upgraded shocks to cure the knock noise. Not particularly helpful when each shock costs circa £350. I had the odd faint knock in comfort mode after my DRC were re-pressurised. I tend to drive mine in auto mode and very rarely hear a knock.

[Rugslasher]

Well mines getting pulled off if it’s DRC again & replacement coil over be getting fitted

[skirs6]

Well I’ve had all the bolts on virtually everything checked yet still a knock doesn’t seem to do it on bigger bumps but tends to be on the smaller ones and more often going uphill or when the rear of the car is lower ie under power. I think it might be something else rather than DRC Any advice much appreciated