'10Q7TDI_Prestige'

Air suspension incorporates adjustable shock damping, multiple ride height/drive modes, automatic load leveling and is pretty awesome in what it brings to the table. Normally it just works in the background unobtrusively, and you select a driving mode via the MMI controller, and the car does the rest.

That said, it is a system with wear parts and will eventually require repair/maintenance. The most common failure is the air compressor, followed by the distribution valve-block (contains the pressure sensor for the system) leaking internally or externally, etc. And sure, on much older cars you may also get to the point where the check-valves at each air bag may begin to fail independently, but those can be replaced fairly easily, if needed. The big enchilada of the air suspension is really the combo air spring/strut mount unit, and if you need to replace the air spring, you are most likely at a mileage point where it is necessary and/or advisable to replace the strut/shock cartridge as well, or just buy a complete replacement unit since the old one has to come off the car either way. Everything else is really just small potatoes up until that point, and pretty straight-forward in what needs to be done to assess and replace any failed parts that are creating errors/faults in the air suspension system. It is most definitely a system. Be mindful that the system's parts don't fail all at once, and it's usually going to be just one or two items that require R&R to get the system back up and fully operational. The common issues that come up require basic DIY skills and minimal, common tools. You will need a VAGCOM, both to diagnose the car properly, as well as to perform the programming/leveling of the car once repairs to the air suspension are completed.

I have the Ross-Tech VCDS; it is the scan tool you should have if you DIY maintain and/or perform repairs on this car...it's a force multiplier; a huge time and $$$ saver.

The original compressor failed on our '15 around 105k miles (7years of service), which IMHO is a very good lifetime for such a hard working part. This was my first experience DIYing air suspension, so I watched all the videos and read a bunch of threads on multiple forums to discern what I was in for. I felt as prepared as I could be, so I shopped around for a new compressor and thought, "maybe I can just get one of those rebuild-your-own-compressor kits from Bagpiping Andy on the cheap", as the OE compressor still runs.

First Attempt: Ordered an Air Compressor Rebuild Kit...Hey, it was really cheap -
After removing/disassembling and noting the amount of corrosion present throughout the OE compressor head and air dryer canister, I pretty much knew it was done for w/o a new cylinder head. Herein lies the rub, as the rebuild kit is very basic; just a new piston ring, a sealing O-ring for the head, couple head bolts, and new desiccant media and filter partitions for the air dryer...no cylinder head was included or optional with the kit at that time...but nowadays it is, or you can order one separately from a different vendor also. So, I forged ahead, diligently cleaning and rebuilding the very worn and corroded internally air pump, and it pumped just slightly better when back on car, but couldn't resolve the pump not making enough pressure/overheating from extended duty cycle required to make any pressure, etc. Bottom line, if you think you are going to get off cheap on parts required you are almost certainly wrong, although it may work better for a while; it's likely not a long-term fix unless you also replace the cylinder head on the pump, which is a wear part. If your old air compressor doesn't still run with some gusto when it first starts up cold, don't even attempt a rebuild...just get a new OE/OEM.

Second Attempt: Ordering A New Air Compressor
Started shopping immediately for new compressor; pricing was high on the OE pump from most vendors, or there was no stock avail where the price was decent for it (FCP Euro). Ended up buying a Cardone branded compressor from Rock-Auto, which seemed to be a great deal in-the-moment. In reality, it was a new, old-stock part that was being sold-off due to it's age. It looked like a work of art and came mounted on a new aluminum support carrier/ frame with new motion limiter springs/bushings, new harness and air pipes; it was a complete, proper replacement kit. The problem; it was a close-out deal and had only a 30 day warranty/return period on it. Normally, the same item sold new, at a much higher price point, comes with a lifetime warranty. I swapped it out and noted the valve-block was leaking down slowly. Ordered a new valve-block assembly and installed; no leaks, pump ran perfect and strong, albeit much more noisily than the OE pump...you definitely knew it was running whenever it kicked on. I surmised the noise factor had more to do with the replacement carrier and dampening devices themselves, which came with the new pump, but seemed a bit lower quality than the OE setup.
It worked great for 60-90 days, then the pump began leaking from the port where pressurized air leaves the pump to travel to the distribution valve. Probably the O-ring inside of there failed from dry-rot is my theory, and I had no recourse at that point. It still worked, but it was leaking and making pump overheat from extended duty cycles...sound familiar. Symptoms: Reach to open the door and hear the hiss from pressure reservoir automatically backfilling the system pressure lost. Turn off engine and hear the air pressure venting from leak at pump outlet.

Third Attempt: Where Can I Buy That Friggin' OE Compressor For Less?
The car is in a different state, literally 7 hours drive-time away, and I'm chasing down a new compressor to install on it at some future point. Part # search online, and FCP EURO, has the OE WABCO unit back in-stock for close to $400 (US currency), it ships free and has a lifetime replacement warranty on it from FCP EURO...sweet! Other vendors were selling same part for double that cost, or even triple, and w/o the lifetime warranty on it. By the time I get up to where the car is located, I find the car is bottomed-out on front axle, while the rear is sitting pretty high in the air; all the 'unhappy' dash lights are flashing and there are five persistent trouble codes.
I decided to try a new approach, and dropped the aluminum carrier down, released the two air lines to the front of car from their 'line holder' clamps at top of the cavity the pump fits up into so that it could lowered w/o damaging or placing undue stress on the lines or connections, and most importantly, not having to disconnect any of the air lines from the distribution valve. Only the pressure pipe line (black) needs to be removed where it meets the air compressor...no touchy the distribution block lines at all.

This worked out really well for me, and I highly recommend this technique to avoid having to replace the original valve-block, since cracking open those old fittings is a crapshoot at best as to if they will seal up tight again and be leak-free, etc. It is important to be mindful of supporting the pump's weight while you are removing/replacing it in the aluminum carrier chassis, etc. I just wedged some of the cardboard protective packing from the new pump's shipping box under it. It was really cold that day, so I was extra careful with the air lines/fittings not being stressed. It went back up, wiring reconnected, trouble codes cleared, and guess what; the pump didn't run at all ---WTF?

THIRD ATTEMPT; PART 2: Troubleshooting Why The New Pump is D.O.A
I still had a varied number of persistent trouble codes in the Level Control Module, and an occasional blip of related error in the TPMS controller, as well. Honestly, I decided to go sleep on the problem and hit it again with fresh eyes and mind. I awoke and remembered the two primary upstream 'governance' bits are the air compressor relay, located underneath the front, lower dashboard (LHD - on driver's side)...pay attention to the retention/release tabs location for the swing-out/down relay carrier tray, and it's pretty easy to swap out...you do remove the lower dash trim pieces to access this relay. The other is the 40amp Maxi-fuse, located next to the battery under front seat...it's large, orange, and the only one out in open sight on my '15 just as soon as the seat is tilted up. I pulled the Maxi-fuse from its' holder, looked inside and saw it was toast...needed a new fuse. Interestingly, I got the generic 40amp Maxi-fuse from NAPA auto-parts for only $2.50, and the pump fired right up after I cleared the trouble codes and switched on the car, running clean, clear, and quiet...so much quieter than the aftermarket one I had in there prior, but I did use the old, original dampers to mount the compressor, so I'm sure that was most of it...something that actually works as intended, as opposed the the shiny, new, aftermarket bits that didn't perform very well at all. Seriously, I can barely hear the new, OE compressor kick-in and running, which is exactly how it should be, and with the radio on I don't even notice it cycling.

TAKEAWAYS: There was no clue that the fuse for compressor had blown except for a recurring 'leak detected' trouble code(duh, no pressure from compressor), and that I couldn't hear or monitor the pump running up pressure in VCDS; trouble codes can manifest and be misleading/confusing, so stick to the troubleshooting basics...i.e. is the pump running post-install, yes or no, and go on asking good, basic questions from there. With the fuse replaced and pump running, the only remaining fault code was that the car needed to have air suspension manually leveled out/calibrated, etc., which is what you do to calibrate the car to it's height sensors data, etc.
NOTE: There are very specific parameters the car monitors to allow you to access and complete the sensor calibration process; read about that in the Ross-Tech Wiki, which is open source info. The highlights are fuel tank must be over 1/2 full, doors & hood shut, battery amps must be above a minimum level, verify no trouble codes before & afterwards, and there are other parameters. I had a battery booster attached to car and it went right through for me following the Ross-Tech instructions.

If You Go Aftermarket For These Parts, Then You'll Be Doing It Over Again and Buying More Parts I did the do-over dance...twice, and ended up spending spending a lot more than I needed to overall, not to mention the extra time it takes when you have the side-step/running-board rails attached to the car, which get in the way of compressor servicing!!!
Buy only the correct parts for the air suspension; that means OE/OEM parts only...they work long-term, and are very quiet too.
The VCDS Scan/Diagnostic Tool by Ross-Tech Will Make Your DIY experience and ownership of this car so much easier...you save $200 every time you hook it up to troubleshoot...that's what Audi charges to hook up their scan tool...just to hook it up and tell you what it says, yup.

I did order the new air compressor relay, even though the one I put in there earlier this year is still functional (since that compressor died a hard death) along with the Audi/VW 40amp Maxi-fuse, which FCP Euro carries also, and here's the reference part # and link to the fuse box overview of this car:

Maxi Fuse - Audi (N-102-519-01)

https://fuse-box.info/audi/audi-q7-4...ses-and-relays

I'm ordering it just in case those tricky Germans used a quick vs slow type of fuse for this application...it's probably exactly the same fuse as what I got from Napa parts store down the street, but I'm playing it safe.

There's also another relay for terminal 15 (battery) located right next to this Maxi-fuse next to the battery, and along with several other majorly important relays underneath the hood (fuse/relay panels under plenum cover) on this car, it's a really good idea to start replacing those proactively since relays that get cycled a bunch don't last forever, and have a outsized negative owner experience associated with their failure. The air compressor relay should be replaced any time you replace the compressor, and there is a new relay spec'd by VW/Audi for the air suspension compressor, BTW, so try to get the new one for it rather than the original, as it is supposed to be more durable.
The main thing I would emphasize is not to despair or give up; none of what I did was technically difficult, it's just some of the videos and advice out there, albeit meant to be helpful, is not always going to give you a good result. Case in point; the shop videos nearly always show just the compressor getting replaced and then them hooking back up the old valve block (or maybe it's not the old one, but they don't tell you that), and what I learned was if you crack that valve block air line seals open, it's even odds as to if they are going to reseal fully again. If you do it the way I described, and leave the air lines attached, and you truly just needed a compressor, then you can save $$$ not having to buy a new valve-block or dealing with small air leaks, which over time will take out your air compressor by making it work harder, and pulling more moisture into the system, which saturates the air drier media and makes the pump work harder, etc., etc.

I had to hunt around a lot to figure out how to get started on this endeavor, so I hope this thread will save you some time and/or unnecessary frustrations by outlining the basics and how I did it wrong after looking at all the available info online ad-nauseum, and wasted several hundred dollars buying aftermarket parts and uncounted hours under the car on a concrete garage floor. If you do it right, it's pretty quick and relatively painless, and more importantly, the air suspension will work perfectly for many, many years to come.

Cheers, and good luck!

5000S

It seems this thread is a good reason to stay away from the air suspension. Some even convert it back to a standard spring suspension.

bg_2007Q7

I was kinda thinking that as well. Just 3 springs would cover what I paid for my 07' 3.6L. Not to mention all the other components that are required to make it work.

But, i understand from reading that air is preferred for towing. All i really to is a hitch mounted bike rack or a small trailer. Not much of a camping fan...

'10Q7TDI_Prestige'

Me thinks you miss the point of this thread, which is to share experiential info (my poor choices) to help others either to DIY or be at least more knowledgeable about what actually/typically wears out on it, and the timelines, so they don't get ripped off taking it into a repair shop.

FYI, we have both a steel susp & an air susp Q7, and both are excellent. We lived in Louisiana for 4yrs, and that's the reason we got the air suspension car, if that tells you anything; the roads there are an absolute horror...it's paving by the braille method, etc. The air suspension you just set to 'Comfort' mode, and cruise right over that hack-job of a road system with minimal intrusion. Air suspension features adjustable shocks (damping), which is not really discussed that I've seen, but it's a huge part of what makes the air suspension so good to have on this car. It even drops the car to a lower ride height at higher speeds to improve aerodynamics and return higher MPG

Air suspension is excellent to have, as it greatly expands this car's utility, towing prowess, ground clearance, load-leveling, and playful/sporting intent immensely. Best of all, as noted, it is relatively easy and not terribly expensive to do the 'normal' repairs on the air suspension if you DIY. If you don't DIY, then you'll be forking over a great deal of $$$, and very likely be getting taken advantage of as relates to your lack of knowledge on the topic...that's just how it works.

The decision point when an airbag eventually goes out (if you keep the car long enough, that is) will be: Do I spend X $$$ to do the repair, or do I spend x $$$ to convert it over to a steel suspension (still a very large number). To that, I would say it's a no-brainer if you plan on keeping the car; it should be no question that you repair the air suspension back to original (sourcing parts on sale, etc.) and enjoy all the adjustability, adaptability, and sportiness it has to offer. It really adds considerable benefit to the Q7 chassis, especially for those of us who like to venture off paved roads and see what this beast can really do. I would venture a guess that most owners have no idea what this 4L chassis Q7 is capable of. The air suspension adds significantly to said capability on, or off-road.

urs6_ma

I think the OP was sharing his wrenching experiences.

I've had five cars with air suspension, and the current generation is the most bullet proof.

You need a good private mechanic. Mine diagnosed a stuck valve on my '10 Touareg TDI and, um, unstuck it. Charged me 1/2 hour labor. Dealer would have replaced two matching bags, probably running $3K-4K.

Wish my Q7 had air. At least it has Cayenne S sway bars, but it still doesn't handle like my Cayenne S (with air).

shakeel

OK I am looking at a 2019 Q7 premium plus which has air suspension installed it is certified
My questions to the members is it worth having air suspension and after my warranty is over
is it very expensive to fix it ?

Pothole5000

I think it is absolutely worth it, especially if you tow or regularly load up a lot of stuff in the back, plus it should resale for more when you go to sell it. I love being able to drive around in dynamic by myself, then flip it to comfort when hauling the family around on the weekends. Also, the number of times I have lifted the car up to nose further into a parking spot and not scrape my front facia on the parking curb.
Air suspension is more to repair than coil springs, and it has more parts that will fail with age compared to steel springs, but I have never fixed anything on either of the two Q7's with air that I have had.

It's something you will have to decide for yourself.

imsolidstate

Nice write up, just want to add that disconnecting air lines is no big deal as long as you replace the o-rings. You can get an o-ring kit cheap these days from amazon. Then use a spray bottle with soap to check the seal.

Also on mine the check valve in the pump cylinder head was one of the issues with the pump not building enough pressure and running more (overheating) after doing the piston ring seal. Unfortunately you can't buy that part, but it helps to at least clean the check valve and seat. Same for the relief valve. The system measures the pressure output of the pump in the valve block before allowing it to fill the accumulator or bags so if your pump is running but not lifting the car the pump can't build enough pressure.

I'm on my fourth Q7, and finally got one with air. It's way more comfortable than steel spring, and one of mine had the "comfort" springs oem. It will lower down and firm up the damping for sporty feel and raise up and soften the damping for bad roads or off road.

-Wes-

Wow; that is sitting really high, and that is just with the air springs?

what is that front lower bumper you have there... something custom or is it available commercially?

imsolidstate

That is the offroad setting, I can go about another inch up or two down. But I'm running a 2" lift and 33x11 tires.
I made the front bumper.