Passenger side suspension drops when sitting static.

[Nicola25]

Audi Q8 - I’ve noticed the passenger side front  suspension drops when the car is off.  No warning lights and suspension moves up when the car has started and it’s fine to drive.  It only seems to be when sitting for a long time. Could that be an airbag leak or defective pipe? Has anyone else had the same problem? Thanks 

Edited January 21 by Nicola25

[Steve Q]

Definitely could be a leaking airbag. I'd recommend a diagnostic check to see if any fault codes flag up 

[Nicola25]

Thanks.

the Car is booked in for a diagnostic check next week. Do you know the costs for repair/replacement ? 

Edited January 21 by Nicola25

[spartacus 68]

Genuine Audi Q8 suspension airbag unit will be over £1k for fronts. Doubt it's the compressor as it's going back to normal ride height on start-up, and likely to be the air suspension unit or the fixing point where the tube enters the unit via a union. These units, although I'm no expert wouldn't need to be fitted as pairs as per normal coil-spring set-up. Possible to find used parts but on a 2020 vehicle but personally I'd opt for new given you have labour to fit. There are after-market parts from reputable makers who probably make them for Audi anyway, but it's all about compatibility.

Suspect there's some sort of configuration once a new part is fitted - again access to VCDS to scan will reveal.

You should be able to find part number here: https://www.lllparts.co.uk/

Edited January 22 by spartacus 68

[Nicola25]

That’s great. I appreciate your input. The car has only done £26k miles so I would have expected to get more miles out of the car  before a new airbag would need replacing. 

Edited January 22 by Nicola25

[Francis007]

Hi Nicola

I was hoping and waiting to see if anyone could reply as I'm afraid I haven't the technical knowledge to help you with your problem.

It looks as though you have received some good advice from the other posters.

Just one thing though. May I ask where you are ? If you do have an airbag suspension problem and that sounds pricey, I do have a Audi specialist garage who I use in Hampshire. 

Matt is a brilliant technical guy who uses genuine Audi parts but he charges half the rate of an Audi main dealership.

Been using him for years on my previous VW Phaetons ( with air suspension ) my previous A8 and now my two new Q8's. I would thoroughly recommend him.

Just a thought.

[Francis007]

Hi Nicola.

Please ignore that last post of mine ! Just looked at your profile and I see you are situated in Glasgow.

Hampshire is a long way to come to save a few bob! My bad.

Hope you get your suspension sorted. 

[Nicola25]

Yes, everyone has been really helpful so far and I’ve received plenty of good advice. I live in the outskirts of Glasgow , so unfortunately Hampshire is quite a distance away. However, I do appreciate your recommendations of your garage - sounds like you’ve got a reliable one. The Audi dealership has already charged £140 for diagnostic check but wants to carry out further checks . Which they quoted £436. I’ve booked in to a local garage for a diagnostic check next week. I do have a warranty cover, but it seems the airbags are not included! 

[Nicola25]

I’ve had 3 separate diagnostics checks at 3 different garages. There are no error codes showing. The last garage confirmed there is no obvious damage, no airbag leak, no corrosion. He said it could be faulty airbag but it’s only a guess!  So I’m not further forward and car is still dropping when sitting for a few hours.  Does anyone know if  this could be an electrical issue or sensor? 

[cliffcoggin]

I doubt it is an electrical or sensor fault because the electrical system is off when the car sags. It is more likely to be an air leak from the bag, valves, or pipe. I would spray or brush soapy water on all the components and watch for bubbles.

[Nicola25]

Thanks for your input. I’m planning to take it over to a different Audi dealership tomorrow. Hopefully get it sorted!

[Nicola25]

My car has been in multiple garages for the n/s/f sagging when parked. No error codes, leaks or sensor issues. Audi dealership have swapped the pipework and the car is still dropping. Now they want to strip out the carpets, seats and check the rest of the pipework. The say it could be the shock absorber but it’s not certain. So where do I go with this. They are quoting £1689 for the shock but when I search genuine  parts i can see you can buy this for half the price. Can anyone confirm a price for Audi Q8 front shock absorber. 

Edited Friday at 06:10 PM by Nicola25

[Leveret]

I thought I'd reply to this as apart from being hopefully amusing it might help someone with a similar air suspension problem.   Although it's about my 'forever car' I think one Audi air suspension strut and compressor system is much the same as another.

A few years ago my 2005 D3 SWB W12 at 70,000miles started to sag at the front when left overnight. The compressor would restore the height and the orange and green lights would go off. But the tiny leak got worse and the compressor sometimes needed two goes at it, presumably because the thermal protection switch would cut in after much noisy pumping. Lots of air was lost from the system when the clever car tried to keep itself level by transferring air from the high pressured accumulator to the lower pressure leaky strut (see Audi SSP 292, P31). If overworked, the compressor or its relay will eventually fail.

To locate the leaky strut, I put it in ‘jack mode’ to prevent level equalisation. Next day only the front driver’s side had bottomed out.

I removed the under bonnet trim to expose the strut's upper mounting, slid the large dust cap back along the black wire, and did the same with the smaller dust cap underneath it. With jack mode off to restore pressure in the strut, I sprayed soapy water around the strut and poured about 15mls into the top of the mounting, not filling it above where the black wire goes in. No sign of leak from the strut air bag behind the wheel but foam appeared on top of the strut mounting. Diagnosis – the tiny top ‘O’ ring has failed, impossible to replace without major work and the garage rejoicing in a big bill for a new strut. I suspect this is the most common failure rather than the larger bottom ‘O’ ring or the tough air bag itself.

I replaced the foam with about 20 mls of clear water. With a magnifying glass I saw a tiny stream of bubbles appearing from below the 18mm locking nut. So I put jack mode back on and waited a couple of days till the bubbles stopped when the pressureless strut had bottomed out. Then I sucked out the water and left it to dry thoroughly. Then I injected a layer of some tough ‘CT1’ sealant. After a day to harden, I added another layer….then another. Then, jack mode off to restore pressure in the strut.  

Sadly, it didn’t completely cure the leak, but it took around three days to sink rather than just overnight. But a little later the WABCO compressor finally failed, rattling away uselessly. Although access is via the wheel arch for most A8 cars, it is impossible for the W12. The front bumper has to expensively come off. So I bounced it along to my capable indy to do this and the compressor, reconditioned with my repair kit from ‘bagpiping andy’, is now silent. I could live with the leaky strut, remembering to put a bespoke 30cm x 12 x 6 wooden block under the jacking point with ‘jack mode’ on if unused for a few days. It’s important to leave the car in ‘jack mode’ so the compressor doesn’t have to replenish the whole system every time the car is used.

Amazingly, a few weeks ago (at 76000 miles) I noticed the car no longer sank onto the block, even after well over a week. Somehow the amazing CT1 sealant (incidentally good for repairing trainer soles!) seems to have almost sealed this top end leak! I hope this story helps someone with a similar problem as I don’t believe I’m the only one with O ring failure which a garage would probably resolve with a new strut and a hefty four figure bill.

[spartacus 68]

Interesting John, and fix.

Just been listening to someone on YouTube with a Q7. They had sagging suspension overnight and replaced airbag suspension up front and the fault continued. According to them this was traced to insufficient tyre inflation. Now this got me thinking, hold on, this is a Q7, TMPS has been in place since 2012, so surely a incorrectly inflated tyre would have flagged an issue?

Apparently there was an update to the story and it was in fact one of the self levelling sensors that was corroded. Would be worth checking them out that there’s no corrosion or damage before condemning the airbag.

[Nicola25]

That’s interesting. My dad, who is now a retired HGV mechanic also suggested the self levelling sensor and we asked the garage today is they have assessed and eliminated this sensor? Unfortunately, the person at the dealership was unable to confirm as they are were not the master technician who was working on my car. I am paying them £216 per hour just for them to say ‘I think it might be’ so I’ve asked them for a detailed report of their findings. the bill is growing significantly, with technicians are effectively dismantling the car without producing any definitive answers. At what point do I say enough is enough and the cause of the issue remains unidentified. This pattern of inconclusive results raises serious concerns about a potential manufacturing fault, rather than wear-and-tear or owner-related issues.

[Leveret]

Insufficient tyre inflation? One or more?  Surely the car would think it was too low and would pump up the bag(s) rather than allow it to 'sag'?   The corroded level sensor doesn't make sense either.  They are flimsy looking articulated things connecting the suspension leg to the frame and it would be impossible for them to seize without breaking.   Also, they don't appear to be prone to corrosion on my nearly 20yr old Audi.   I would have thought if one was u/s it would have thrown up a code of some sort.  

[Leveret]

10 minutes ago, Nicola25 said:

.... with technicians are effectively dismantling the car without producing any definitive answers. 

The sagging must be caused by either a leak or a problem with the control system.  The history of the problem is important.  You said that it  'only seems to be when sitting a long time'.   If it was the control system,  the sagging would be present immediately, I think.   If the level is OK for several hours, and then gradually sags, that is suggestive of a small leak gradually reducing the pressure in the strut.  Have a thorough read of my post above and ask your expensive mechanics specifically if they have sprayed the strut bags with Fairy Liquid water  (makes lots of giveaway bubbles) and also done the same as I did at the top of the strut housing to check the top O ring.  It only takes a few minutes to do,  and should have been the first thing they did.

[cliffcoggin]

3 minutes ago, Leveret said:

  It only takes a few minutes to do,  and should have been the first thing they did.

You'd have thought so from the point of view of a practical mechanic, but the "master technicians" that Audi employ can only plug in their computers and read the screens, and if the computer says "no" you are out of luck yet still face a large bill.

[Nicola25]

Thanks John. I’m no mechanic but I feel like I’ve looked at the components that much and read what checks are suggested that I could fix it myself 😂 however, when they say the master mechanics are on the job you would expect them to carry out these checks as Part of the elimination process.  I have asked for a detailed report of what the master mechanic has worked on so far. Surely, a master doesn’t need 4 hours to identify the problem. Now they are asking me to approve another 2 hours and they want to strip out my carpets, seats and check the rest of pipes. I honestly can’t believe this issue has been ongoing since January and not one garage can’t get to the bottom of it.  

Edited 23 hours ago by Nicola25

[Nicola25]

..

Edited 23 hours ago by Nicola25
Duplicate message

[Nicola25]

Clifford, I tried to avoid going to the dealership. However, as the issue has been ongoing for so long without a resolution. I decided to contact Audi UK as it makes me think it could be a manufacturing fault. Audi UK informed me they wouldn’t look into it until I got one of their Audi technicians to investigate. So I’ve been I touch with Audi again and I’ve let them know their ‘technicians’ are investigating the problem but do they think it’s fair or reasonable to expect a customer to keep paying thousands of pounds just for the technician to say ‘I think it could be’ at this rate I’ll be selling my house to pay for the repair! 

[spartacus 68]

You’re in a bit of a predicament Nicola. The trouble with main franchise dealers, and this isn’t exclusive to Audi, is that their technicians aren’t experienced enough. As mentioned earlier, if anything like BMW, then they will log onto a computer terminal and follow as prescribed route to fix and don’t use old fashioned intuition. That’s fine if they actually fix it, but as a customer you take the hit with exorbitant labour and parts.

Personally, I’d take the car back from Audi dealer and continue with your route to Audi UK to see if they can address it. This is a luxury SUV, 5 years old, and shouldn’t have something that’s unfixable.

There must be some sort of monitoring system for air suspension that provides live data. The fact the car self levels on start up tells you the compressor is doing its job. I’d want all the self levelling height sensors checked. That should have been done as a matter of course, and with live feed to VCDS to see functionality.

Airbags, as mentioned by John, inspected properly. Whether it’s the airbag, ‘o’ ring or line feed union. Audi won’t repair, I will tell you that now. If there’s a fault then they’ll opt to replace. The air lines traced to see if there’s a break along the length of the car from the compressor. That’s why they want the seats out. I think at that point, then this repair should be goodwill, as stripping out interiors is time intensive.

I gave up on main dealers years ago and do my own work. VCDS is useful, but Audi will use systems such as ODIS with component security protection which is dealer level software that your average mechanic won’t have access to. On the latest Golf MK8, you can’t even change the rear pads without ODIS is my understanding.

Anyway I hope you get a resolution to this.

 

[Leveret]

Just to add a thought;  it sounds as though the mechanics are trying to find a leak.   Just as in a house, the 'pipework' almost never gives trouble because there is no wear or movement.  If it does owing to poor fitment or a manufacturing fault, it's usually very early on its life.  (The brake fluid pipes on my 45yr old TR7 are original).   Just make sure the mechanics have thoroughly eliminated a leak at the strut airbag, especially its top O ring.  You cannot detect this unless you remove the rubber bits under the bonnet on top of the strut as described in my long post above, pour in Fairy Liquid water and look for bubbles.  Pointless to examine the pipes unless this has been done and a strut leak confidently eliminated.

Edited 13 hours ago by Leveret
PS No special tools required - you could do it yourself!

[cliffcoggin]

It's inevitable that the more complex one makes a machine, and modern cars are extremely complex, the more prone it is to failure unless built and maintained with levels of quality assurance that are unaffordable to individuals. That is why airliners cost many millions of pounds to buy and to maintain. There's a lot to be said for simplicity when it comes to reliability.

Like Richard, I stopped going to Audi dealers for maintenance and repairs years ago because they were too expensive and too incompetant. Their electronic diagnoses are all very well when they work, but the technicians do not seem to have the practical experience and rational thought processes to fall back on when the computers don't work.

Independant VAG specialists were my choice. They combined the intimate knowledge of a specialist with a level of service long lost by the large corporate dealers. If you can find one make him your best friend.

[Nicola25]

I agree Richard and Clifford. Unfortunately in today’s society so many people rely upon  technology that they can’t think outside the box. Take for instance, buying shopping. The shop assistant puts through your shopping, tells you a price, for example £14.89 and you hand them £20. But then you find the 89p in the back of your purse and offer that. Many people can’t figure out the change without the machine telling them!  However, this luxury SUV has every warning lights and sensor you could imagine so you think it would flag something on the dash.  I’ve asked for a breakdown of the work and what’s been eliminated so far. I will not be authorising stripping out carpets, seats and pipes until I’m satisfied that they have checked the common leak points and the self levelling system first.  The car 5 is years old and  28k miles. I don’t drive like a racer and it’s been serviced and maintained every year.  So I don’t imagine there is anything major and it’s purely down to wear and tear. I just hope that I get to the bottom of it, without having to shell out more money for the incompetence of the franchises

Edited 10 hours ago by Nicola25