Are my DRC shocks dying?

[iluvmercs]

Good afternoon everyone.

I've noticed my car has a slight knock from what sounds like the off side rear suspension. It only seems noticeable on a cold start for the first few miles, then it disappears.
The rear also seems to be a tad lower than it has been. It's not too evident, I've just noted that my pressure washer's lance is recently a bit closer to the bodywork when cleaning the arches. I haven't had the wheels off to check for any seepage.
I haven't noticed a detrimental affect in handling, but if it's a gradual change, it could be forgivable for not noticing any change.

My car has just ticked over 80k miles, and to date the original DRC shocks haven't given any trouble. Considering this, I have wondered if (and when) they will give out.
I don't wish to go the coilover route, nor am I keen to go for a repair. I'm sure those routes good, but I'm just after a straight swap for new warranted items from my main dealer.
My car has the Sports Suspension Plus, so is there any difference in the shock of which I should be aware?

I know they are to be replaced in diagonal pairs, so should I be preparing myself for a large bill, or could my symptoms be something else?
If it the shocks, is anything else worth replacing while the mechanics are there? (I'm thinking springs and rubber bits.)

Any and all thoughts and suggestions are welcomed by you guys
Thank you.

Darren

[rob-s]

I am no expert in DRC but know something from experience..had my car's DRC recently repaired.

In would in the first place remove both rear wheels to check for leakage. If it only leaks on one side then it is possible to only have that one replaced and have the pressure tested and filled on one circuit. On the other hand I would recommend that they test both sides.

I had on my SS+ suspension the rear shocks replaced with standard ones because I wanted the rear to be a bit softer. On my car the valves (both) and front lines (that crack) were replaced. Now it goes like new again

[Rw@@dy]

Could be worth getting the pressure checked first before doing anything.

[MikeFish]

Also worth checking the diagonal fronts. I was sure my front right shock had gone as that was where the noise was coming from. When I took it to Unit20 they checked them all and found it was the rear left that was leaking but this cause the pressure to appear to have been lost from it's diagonal pair.
Also, Unit20 do not say they should be changed in pairs. I had one leaking which they recommended to be changed. Another 2 had slight misting but no actual faults; but as my car was having the springs changed for the KW ones at the same time I told him to change the 2 misting ones as well. There was no mention of the need to change in pairs. If this has been mentioned before it is probably from a dealer that doesn't know the DRC as well as Unit20.

[Covkiller]

Bin the DRC and gets some KRW's

[CaptainLeadFoot]

I don't think the shocks are the problems if you have a leaking one, since it'll just keep pumping hydraulic fluids until your reservior is empty, you can see leaks easy though just with a torch and inspect each shock.

Also check your control arms, ball joints and bushings. I also had the same problem at the front with noise just when it's cold, the front ball joints are on its way out and I changed the entire set of front control arms.

[iluvmercs]

Thanks for all the replies, and apologies I haven't yet replied here.

I have my car booked in for a service and Audi warranted corrosion repair in a couple of weeks when they will also perform a pressure test as well as thoroughly check all the suspension.
I've now noticed some dampness around the top of the shocks at the back.

If one or more of the shocks are at fault, I will have all four replaced as I'm certain the good ones won't be far behind.
Assuming the worst, I am happy to have had over 80k miles from the DRC, them being a known troublesome issue!

Once diagnosed, I'll let you all know the outcome.

Thanks again everyone
Darren

[chuckrs4]

Could just be a broken coil on the rear. My near side Spring snapped a coil and it squeaked and knocked till I removed the broken bit then replaced the spring and it was fine after

[iluvmercs]

UPDATE:

I recently collected my car from the dealer, so thought I would update this thread.

Upon checking my DRC, it was determined that both front shocks were leaking.
The near side shock required replacement, while the off side was weeping, but was outside Audi's tolerances for replacement. After discussing with the tech and service lady, I was told Audi may look at Goodwill, but only the one shock which definitely needed replacement.

As people have said in here, I had it confirmed that diagonally opposing shocks need not to be replaced at the same time, just one at a time.

As it was, Audi UK didn't entertain any Goodwill, so in hindsight I could have got both fronts done. I suspect Audi UK saw a rather large claim against my car for bodywork corrosion and perhaps decided I should pay in full for my shock

The system was then pressurised.

I have driven approximately 100 miles since this work and can report she drives like a dream with not rattling from the rear. Turning in feels much better, and the car is more stable at a cruise.
I must say it highlights just how you can be ignorant to a fault when something slowly deteriorates only to have it fixed and the car is transformed!

I will be having an MOT in the next month after driving some hard-ish road miles so we'll see if any further leaking is detected from around the car.

Thank you all for your replies to this thread and I will endeavour to update it if anything further occurs. One shock down, three to go!

Darren

[Holtyrs4]

I'm having a similar type of problem, when I get in my car for the first 20-30 mins I get a knocking from my rear left but after that it drives sound. My local garage is convinced it is my exhaust rattling, I'm not so sure tho?