01 Allroad suspension nightmare. PLEASE HELP

[nochance9]

A few months ago i drove 2,000 miles to buy my 01 2.7tt mt 140k allroad. (my first Audi) well, ive been having some problems with the air suspension and i've used up all the info that i've been able to find on the forums and now need your help before i drop any more coin ( a limited resource for this college student ) So, here's all the data points i have...

- Dealer reports erratic suspension function.
- Hissing sound from front left bag.
- Could not lift suspension on compressor alone (neither front corner would raise).
- Both fronts riding on bump stops.
- Headlight auto level error came up for a while then went away.
- When assisted with floor jack, suspension would only hold pressure at level 3 for one hour before bottoming out again. (still on stock bags)
- New bags and shocks installed, now will not support any weight of the car.
- Compressor rebuilt.
- VAG com shows all level sensors working
- VAG com shows 6.1 bar in reserve tank.
- VAG com showed the valves for the front open.
- 4 Faults Found:

01400 - Suspension Level Control
11-10 - Control Limit Not Reached - Intermittent
01577 - Turn-Off due to Over-Temp
35-10 - - - Intermittent
01575 - Control Switched Off
35-00 - -
01770 - Temperature Sensor for Level Control Pump/Compressor (G290)
30-10 - Open or Short to Plus - Intermittent
- Rears have always raised and lowered normally.
- Switched front and rear airlines at the valve block, all four corners failed to fill. Switched back, and rears worked normally again.
- Removed valve block from car, put air tool oil in the inlet & outlets, let soak, then emptied, reinstalled, no change.

Please help, i am completely lost. I'm done buying parts that don't fix my problem . So, before i buy a valve block i wanted to get the input of the knowledgeable people here.

Also, has any body bought a valve block from these people? http://www.air-suspension-shop.com/A...sion-4F0616013

[4rings2turbos]

Is the compressor loud when it runs? I rebuilt my compressor before and my guess is that the cylinder was already too worn from piston slap that even the new ring didn't help. Had to replace the compressor with new.

[nochance9]

I don't really have anything to compare it to, but it did quiet down a lot after the rebuild.

[SteelyS6]

The compressor was really loud in mine as well from trying to keep up to a leaky bag and well from being 11yrs old. Replaced the leaky bag and installed new compressor and it's perfect now.

[glennda5id]

This is a surprisingly detailed description of how the system works:

http://www.donnagrossmancasting.com/...ension%202.pdf

[glennda5id]

I dont think the valve is the problem.

The system attempts to raise the rear first. You know the rear springs work and the rear valve controls work. If you swap the lines front and rear you should see the fronts start to rise. I'm not sure what would happen at this point as the system is expecting the rears to rise, but you should still see the fronts start to move. If the fronts aren't moving I would suspect an issue with the air lines or the air springs.

[glennda5id]

I have another idea. Have you tried pressurizing the system and using a jack to assist the front since you swapped the air springs? I would try that and see if they pump up and if they hold air. If they do, then I suspect your pump is worn and unable to create enough pressure to lift the front of the car which is much heavier than the rear of the car. Can you monitor pump pressure from vagcom?

[4rings2turbos]

He mentioned that he tried with a jack.

The compressor should be whisper quiet when running if no piston slap. I'm with SteelyS6, if you have known leaky bags I would start there and see what happens. If it improves then it's probably the combo of compressor + leaky bags.

[glennda5id]

He mentioned that he tried with a jack.

The compressor should be whisper quiet when running if no piston slap. I'm with SteelyS6, if you have known leaky bags I would start there and see what happens. If it improves then it's probably the combo of compressor + leaky bags.

He has already replaced the bags. He mentioned that he used a jack before swapping the bags but he didn't say if he tried after swapping the bags. I suspect his bags were leaking and over worked the compressor. The bags have been replaced but the compressor may still be an issue. If he tries jacking up now and the bags hold that only leaves the compressor.

[julex]

who replaced the bags? Were bags pushed down over o-rings to ensure seal?

I would simply take off both front wheels, place the front on jacks and then inspect where the air is escaping. Usually it is bottom oring if the bag was not pushed down hard enough.

[nochance9]

He has already replaced the bags. He mentioned that he used a jack before swapping the bags but he didn't say if he tried after swapping the bags. I suspect his bags were leaking and over worked the compressor. The bags have been replaced but the compressor may still be an issue. If he tries jacking up now and the bags hold that only leaves the compressor.

I have done that, the bags make no attempt to support the weight of the front. Also, just by looking at the bags, i can tell that the front left is receiving more pressure than the front right. It looks bulged where as the front right is still wrinkled. Would a worn compressor be able to produce 6.1 bar in the reserve tank? What is the normal pressure supposed to be in the reserve tank?

who replaced the bags? Were bags pushed down over o-rings to ensure seal?

I would simply take off both front wheels, place the front on jacks and then inspect where the air is escaping. Usually it is bottom oring if the bag was not pushed down hard enough.

I installed them, and i felt confident that the seal was good, however, i would not rule out a mistake on my part. I will check that out, thanks.



Mostly i am confused why switching the front and rear air lines ended up bottoming out both the front and rear, then continue to work correctly in the rear when i switched them back. This makes me think that not only is air failing to get to the fronts, but when it does send air there is a sufficient enough leak in the front to show no height change.

[glennda5id]

IMostly i am confused why switching the front and rear air lines ended up bottoming out both the front and rear, then continue to work correctly in the rear when i switched them back. This makes me think that not only is air failing to get to the fronts, but when it does send air there is a sufficient enough leak in the front to show no height change.

As I stated earlier, the system attempts to fill the rears first. I suspect if it can't level the rears it can't level the fronts. I think you have a leak in one of your front bags. When you have it in the correct config for the valving the car levels the rear then levels the front but the leaking bag prevents the fronts from filling. When you swap the lines at the valve, it attempts to fill the rear which you have attached to the fronts which have a leak. It probably gives up after a while when it sees no movement from the rear sensors.

Is it possible for you to plug the line going to the front bag that is not inflating at all and see if the other bag fills?

[nochance9]

As I stated earlier, the system attempts to fill the rears first. I suspect if it can't level the rears it can't level the fronts. I think you have a leak in one of your front bags. When you have it in the correct config for the valving the car levels the rear then levels the front but the leaking bag prevents the fronts from filling. When you swap the lines at the valve, it attempts to fill the rear which you have attached to the fronts which have a leak. It probably gives up after a while when it sees no movement from the rear sensors.

Is it possible for you to plug the line going to the front bag that is not inflating at all and see if the other bag fills?

I'm not sure if it is possible, but i can look into blocking the line. But the two sides are controlled separately aren't they? PS: I have swapped the front lines from side to side, but there was no change, left was still bulged, and right was still clearly empty. This gives further evidence to the leaky o-ring theory. If i didn't get a good seal on the right bag, would the system decide not to fill the left bag so it matches the height of the right? PPS: When i had the VAG com hooked up and it attempted to fill the fronts, the left side would raise about 3mm (not something I would have seen with my naked eye) while the right would raise 0mm. At the time i thought that it was the valve failing but now i think the computer might be deciding not to fill it.

What you said makes sense about the rears filling up first and it giving up. So, do you think i could swap the lines and use a jack on each side of the rear to fool it into thinking it has filled the rears, then when it switches to what it thinks is the front, it should actually fill up the rears. This would tell us if the valve does actually send air to the fronts when wired correctly.

[glennda5id]

The system can independently control each bag, however when it fills it fills both bags in each axle at once and then makes fine adjustments side to side once it is close. Let's say you are at 0 and the system commands 10. It will open both front valves and fill at the same time, but close them independently once each side hits 10. So as soon as the right hits ten it will close and as soon as the left hits 10 it will close.

When both valves are open the systems are bridged and a leak on one side will render both sides inoperable. This design minimizes one side being significantly higher than the other which is probably not safe for driving.

Also, no need to swap front and back. Everything you have done has shown that the valve is not the issue. I suspect you have a leak in the right side line, connection or bag.

[nochance9]

The system can independently control each bag, however when it fills it fills both bags in each axle at once and then makes fine adjustments side to side once it is close. Let's say you are at 0 and the system commands 10. It will open both front valves and fill at the same time, but close them independently once each side hits 10. So as soon as the right hits ten it will close and as soon as the left hits 10 it will close.

When both valves are open the systems are bridged and a leak on one side will render both sides inoperable. This design minimizes one side being significantly higher than the other which is probably not safe for driving.

Also, no need to swap front and back. Everything you have done has shown that the valve is not the issue. I suspect you have a leak in the right side line, connection or bag.

Just checked it out today. Pulled off the wheel, pushed down on the lower part of the bag.... And IT WORKS! Thank you guys so much. I've been chasing this problem for three months now and I can finally drive my new car. 👍

[nochance9]

New problem, been a couple weeks since i re-checked the lower seal. over the past couple weeks I've noticed the suspension error light come on intermittently at startup, but would clear when i took out the key. It didn't do anything wrong that i could notice, that worried me, but i didn't know what there was to do.

So, this Saturday i went camping, drove about 1.5 hours on a dirt road, so i put it in level 4, just because i could. Well, on the way home, the car would not lower down from level 4. Then, the front two started sinking little by little over the past two days (the level light would read 4, then 3, 2, now 1), until today the front right was on bump stop, front left on level 1, and the rears on level 4.... WTF?! Can someone please help me?

PS, i think that i might have stripped the plastic threads in the genII bags when installing, especially because i unscrewed and reinstalled the air lines about 8 times...

[4rings2turbos]

Was the suspension light lit in the cluster while it was sinking over time from level 4 to level 0? Because you cannot adjustable the height and it won't automatically while there is a fault (in most cases).

Have you scanned for faults?

[nochance9]

Was the suspension light lit in the cluster while it was sinking over time from level 4 to level 0? Because you cannot adjustable the height and it won't automatically while there is a fault (in most cases).

Have you scanned for faults?

The error light only comes on when it tries to change the suspension level, and resets after cycling the ignition. So, at first when it was all at level 4, the light would not come on until i went above 55 (or whatever the seed is where it tries to drop the suspension) OR tried to manually tell it to lower. Now however, it seems like it wont get the fronts up to match the rears, and then throws the error light. i did scan, when the fronts were still at level 4, i tuned the key on, no error light, then told it to lower the suspension, then the light came on. just said something like limit could not be reached, i cant remember exactly and i don't own a cable myself yet.

[glennda5id]

You need to scan for codes. I would suspect maybe a level sensor issue? I found that the wire harness clips for my front sensors were not holding in. I used some zip ties and have not had an issue since.

If you don't have access to a scanner push the level sensor harness in and make sure it is fully seated.

[nochance9]

Texted my friend, he remembered 01400 error code. And I don't think is a level sensor because we could see all of the height readings when we read the code.

[glennda5id]

1400 seems to have a lot of issues:

Power Supply Too High
Power Supply too low
Adjustment level step undercut - Possible leaks, thermal cut off (pump too hot)
Adjustment limit exceeded - Thermal cut off

Maybe you burned the pump up being up at level 4 and then the system was shutting down to prevent overheating.

[nochance9]

1400 seems to have a lot of issues:

Power Supply Too High
Power Supply too low
Adjustment level step undercut - Possible leaks, thermal cut off (pump too hot)
Adjustment limit exceeded - Thermal cut off

Maybe you burned the pump up being up at level 4 and then the system was shutting down to prevent overheating.

Possible. When we had it hooked up I only had 2 bar in the reserve tank...

[nochance9]

But why would it not lower the rears down? That doesn't require the pump.

[glennda5id]

I can't say, its possible that if the pump is overheating or blown then it will stop all activities. Can you clear the code and see how quickly it resets?

[nochance9]

I can't say, its possible that if the pump is overheating or blown then it will stop all activities. Can you clear the code and see how quickly it resets?

The code clears every time I turn the ignition off.

Then, when I start the car, it flashes while it tries to raise the suspension, after a while it goes solid.

Also, I don't hear the pump start until AFTER the error light goes solid. So it's not actually running the pump while it tries to raise the suspension.

Also also, I have only two weeks regular driving after I rebuilt the pump with bagpipingany kit.

[UV_Blue]

My crystal ball says the temp sensor connector has corrosion! Where do you live man? I didn't know anyone in Utah had an Allroad and cared about it!

[nochance9]

My crystal ball says the temp sensor connector has corrosion! Where do you live man? I didn't know anyone in Utah had an Allroad and cared about it!

I'm clear up north right by the Idaho border.

I'll check the temp sensor when I get under there and check all my wiring, thanks.

Yeah, I care about my allroad.... Less and less every day. Lol I've owned it for 3 months now and have two weeks of solid operation.

[UV_Blue]

Well if you sell it I'll buy it Let me know if I can help at all. I'll pm you my cell number. You going to camp allroad?

[nochance9]

Ok, so i finally got around to working on it today. As a reminder, this is what it did before today.

-Would not lower out of level 4
-Over 3 days, FL lowered to below 1/above bump stop, and FR lowered to bump stop, both rears still at level 4
-Pump only came on AFTER the error light came on

This is what i did.

-Disconnected all height sensors and cleaned terminals with contact cleaner
-Checked the temp sensor-its not corroded
-Cleaned all connectors by the pump with contact cleaner
-Let the air out of the rear bags
-Drove it to the car wash and back (up to 60 mph)

This is what its doing now.

-Air pump still only comes on after the suspension error light (runs for a good long time)
-FL raised to level 1
-RL raised to about level 2
-Both right side bags will not lift off bump stops
-When i drive it around the Suspension error light, ABS, and ASR lights all come on

WTF?! If i have to buy one more part for this over $100, i'm getting coilovers.

[A Stupid Turtle]

I don't mean to pursue you, but depending on financial reasons I'd most likely so coil overs... I've had a few issues due to neglect on a few I've seen, but if you're alright with not having the levels, the conventional set up is simple..

[A Stupid Turtle]

Pursuade_

[nochance9]

I don't mean to pursue you, but depending on financial reasons I'd most likely so coil overs... I've had a few issues due to neglect on a few I've seen, but if you're alright with not having the levels, the conventional set up is simple..

That's it, you PURSUED me. haha I was sold on the Allroad before i knew about the air suspension, so, why not now? I even have a local junk yard with like 6 A6's there i can get the parts from for cheap.

Any experience on here between the H&R's and the FTG's? if i go FTG's i could afford to get the H-sports at the same time.

[A Stupid Turtle]

No personal experience; i've heard people averaging 100k on a good coil over setup. I also "heard" that the H&R setup is very good at reducing body roll more than expected.
I'd say buy the H&R and buy the h sports down the road!