First air suspension issue

[mannyo]

Those three faults could be because of three first thing starts perhaps then. I do wonder, where I have to park here on the farm the car is not on the level, so one of the four corners ends up with more gap between tyre and wheel arch because of uneven ground. At work and elsewhere, the ground is always even and flat.

I have cleared the codes and for now they have not returned. I'll scan the level module again in a few days and see what crops up. Previous to this I last cleared the faults on the 30/12/13. The car was then driven on the 31st Dec, 2nd, 3rd and 4th Jan. Yesterday it completed four journeys and the rest were two.

[mannyo]

I do however have a feeling the 01772 will return, I have just looked through the first scan I managed to do just after buying the car. At the time there were a lot of the errors (and I mean lots) due to the car having a duff battery. Buried in the level control module is this.

01772 - Signal from Level Control Pressure Sensor (G291)
008 - Implausible Signal - Intermittent
Freeze Frame:
Fault Status: 00101000
Fault Priority: 3
Fault Frequency: 162
Reset counter: 37
Mileage: 202012 km
Time Indication: 0
Date: 2013.05.06
Time: 11:59:35

So it looks like that fault has been occuring on and off for several thousand miles. Maybe the compressor has issues first thing.

[mannyo]

Must be the season for problems.

Just been out to the car, suspension still at normal height after sitting for more than 24 hours.

Start engine, no suspension lights. After 5 mins running, amber light pops up again. All options still available under car on MMI.

Stop engine, and restart. All lights are out, car still goes up and down. Left running for 10 mins, no faults showing or anything.

Select LIFT, get out of car and listen to compressor by nearside front (difficult at the moment because the exhaust flexi has a hole in it). Not sure, but what should a good compressor sound like? Should it be audible above the sound of the engine, what does a failing one sound like.

From Auto to Lift, how long should it take before the rear and front of the car raise?

When left on Automatic how often would you expect to hear the compressor kick in?.

Sitting in the car, with the heater and aircon off I can hear the relay clicking as the compressor switches on/off.

Can I use VCDS to measure anything to tell me weather its the compressor or something else.

The car is having its cambelt and what have you changed on Tuesday, I'll ask the specialist to take a look at the compressor whilst they have the front end off. The specialist is 15 miles from here and they are collecting it and dropping it back later.

If the compressor is declared dead/dying then I'll most likely have to layup the D3 and go back to the D2 for the time being until I can get it fixed. I have found a source for a replacement compressor/relay in Germany, but I need the car to be reliable daily, and to be sure that replacing the compressor and relay is the first thing to try.

[Delboy]

This may be worth while looking into see attachmens

[mannyo]

Car is back from the workshop after the cambelt change. The suspension issue is FIXED, hopefully.

After changing the cambelt, they set about my suspension. First they checked all the components externally, so the Valve block and its air and supply connections, the compressor connections. Then onto VCDS.

First they checked the suspension level control measuring blocks and discovered that the car thought that each corner was at completely different heights.

Before sorting that, they then checked the electrical connections on each of the level sensors. All were OK, except the NSF which when disconnected showed signs of water ingress. The inside was green from corrosion, so after cleaning it all up everything looked ok so it was reconnected.

Next they sorted out the suspension ride height issue above by recalibrating the whole lot one corner at a time. The car now has all 4 corners at the correct setting, which is good. The car raises and lowers correctly, and all 4 corners look the same.

After a road test the suspension issue itself has now cleared. Hooray (lets hope it stays that way).

BUT the compressor is weak. Rather than replace the whole compressor, they recommend using the repair kit from Ebay and having the existing compressor rebuilt. They have done quiet a few Touregs with the kit, and never had an issue with it. Currently the compressor is running too often ,as it struggles to cope with the demand placed on it. There is no air leak, which is good.

The cost of the work done so far on the suspension, £0. all done for nothing, since they know me.

Now to source the repair kit from Ebay.

[Delboy]

Thats a result on the suspension.

The level sensors work by sending a pwm signal back to the module so if there was moisture in there that would definitely screw things up.

Hope you compressor rebuild is as painless.

[PsYcHe]

compressor could also be running too much as it'll be constantly letting air out and pushing it back into the system to try and level it out when it's confused.

[jonk]

Good luck for the repair... Let me know how you get on. Just lift that is sometimes available or not at the mo, so perhaps the compressor is weak. For £25 I may just buy the kit and suggest the guys fit it when it goes in for the parking sensor replacement next week. Mine is 03 so an early one, lowing miles but 10 years old may need the piston rings doing.

[mannyo]

Spoke to the mechanic earlier, he has fitted the kit and the suspension is back to full working order. The car now raises and lowers correctly, I'll test it myself when they deliver the car back.

He is bringing the old parts back to show me how bad it was, apparently air was escaping around the compressor piston because of damage to the old part and that is why the pressure was low. I'll post a picture of the old part when I get it back later.