Allroad Air Suspension Compressor strip & repair

[bagpipingandy]

Hi Andy, I finally got around to fitting the ring kit this afternoon I bought off you last summer!. I did it in situ on my allroad. Unfortunately the ring seems to be performing fine, but I now have a very loud vibration noise when the pump is running. Any ideas what I may have disturbed? I ran out of light to investigate this evening. Regards Andrew

Hi,

couple of things to check:

does the car lift through the levels ok?, if the ring is fitted incorrectly or upside down it will be noisy but it would not lift fast,

if it lifts ok,
check the compressor is still sitting on its springs, if touching the car body it will transfer the vibration through the body, same for cables and hoses they will transfer noise

is the mounting endplate still attached?

make sure the bolts holding on the cylinder are actually clamping the cylinder on and not jammed or bottomed out

best to look at it while it is running, it may be obvious when you can see it in the daylight, any questions just ask

best regards

Andy

[WhiteyAR]

Hi Andy, thanks.

Yes it's lifting fine and no warning lights. I only removed the cover plate, and then undid the two bolts to lower the compressor lower body, swapped the ring, and put it back together. I guess from what you say I may have twisted the compressor and it's not sitting on its springs etc. I will investigate tomorrow.

Thanks Andrew

[bagpipingandy]

Hi Andy, thanks.

Yes it's lifting fine and no warning lights. I only removed the cover plate, and then undid the two bolts to lower the compressor lower body, swapped the ring, and put it back together. I guess from what you say I may have twisted the compressor and it's not sitting on its springs etc. I will investigate tomorrow.

Thanks Andrew

Ok, that's fine, best to check the compressor it should sit freely and bounce in its springs, I can imagine removing the bolts will have twisted disturbed how it sat, hopefully that's all it is,

best regards

Andy

[WhiteyAR]

Hi Andy,

All sorted. I had a look this morning, took the protective cover off and had a look while the compressor was running. It seemed to be sitting correctly on the 3 mounting springs but still had a massive vibration. I noticed the temperature sensor on the torx bolt was loose (I could not remember if it was loose or not originally when re-assembling last night). I had used the torx bolts you supplied when re-assembling last night, so decided to check the length against the originals. The originals were slightly shorter, so I re-assembled using the original bolts and all fine! I did not have any Loctite, is that an issue? I took a photo of my compressor for your reference, which I can email you if you like. It's a 2005 4.2 Allroad.

Thanks again for your advice.
Regards
Andrew

[bagpipingandy]

Hi Andy,

All sorted. I had a look this morning, took the protective cover off and had a look while the compressor was running. It seemed to be sitting correctly on the 3 mounting springs but still had a massive vibration. I noticed the temperature sensor on the torx bolt was loose (I could not remember if it was loose or not originally when re-assembling last night). I had used the torx bolts you supplied when re-assembling last night, so decided to check the length against the originals. The originals were slightly shorter, so I re-assembled using the original bolts and all fine! I did not have any Loctite, is that an issue? I took a photo of my compressor for your reference, which I can email you if you like. It's a 2005 4.2 Allroad.

Thanks again for your advice.
Regards
Andrew

Hi Andrew, the old bolt should be fine, the new bolts are tight to go in because of the pre-applied thread lock, I actually provide an M6 tap now in each kit to help clean the threads, I guess you purchased it a while ago, the old bolts are usually 2 different lengths too, one short for the bolt without the temperature sensor and 1 longer to compensate for the temp sensor, it shouldn't have been bottoming out but it may certainly have felt tight due to the thread lock, giving the effect it was holding the cylinder on.

i'm glad its resolved,

thanks for your feedback,

best regards

Andy

[kid-jensen]

Just completed the piston ring replacement using one of Andy's wonderful repair kits.

It was the usual miserable experience that working under the car usually is, but the kit itself is brilliant at bringing the air pressure back to nearly-new levels. A whole lot quieter, too.

As a bit of advice to anyone taking this on, bargain on ALL bolts that you try to undo actually breaking! I don't consider myself particularly ham-fisted, but of the 5 bolts you need to undo, 4 sheared-off.... despite careful working back and forward and gallons of penetrating oil.

I was hoping to do the job in situ, but once the cylinder head bolt broke, the compressor had to come out. I had the most trouble with those latching electrical connectors, which seem to always give me trouble everywhere else on the car. They came apart eventually, but there's no access to get a screwdriver to the latching mechanism without taking the compressor off the car first (and you need three hands!). With the compressor dangling on the wires, the connector latches can be accessed reasonably easily.

Thanks to Andy including a M6 tap, the broken bolts can be drilled-out and re-threaded. Stuff loads of rag unto the gap between the pisston and the crankcase to stop swarf getting in, then drill very carefully, starting with a small drill and working up to the root diameter of the bolt, constently checking that you're drilling straight down the mniddle of the bolt remains. Once you're happy that the hole is roughly in the same place as before, tap it out again amd procede from there..

The sheared-off bolts which were (once) welded to the spare wheel tray can be drilled-out from underneath and replaced with loose bolts and nuts with locking washers.

I hope my experience will help somebody in the future..

The reason for all my rusty aggravation came to me as I layed under the car. When getting facefulls of dirty grit from the underside of the chassis, I noticed that they tasted salty... The last time our genrous council salted the roads around here was last February. So, this salt has been clinging to my chassis, glently rusting it away for the last 8 months.....probably continuously, since the first time the car was driven on a salted road from new!

It's amazing that Audis last as long as they do. Maybe it's deliberate governmant policy to slowly rust our cars away so we keep buying new ones. I guess it all stokes the money-go-round...

The first of those East-european car-wash placees to offer chassis-washing will get my money!

[Charlie_allroad]

Can anyone suggest what one wheel sinking intermittently, while parked, would indicate... Faulty valve?


BTW, changed my piston ring for an Andy one about three months back and still very pleased, pump runs like new!

[r7ehw]

I wonder if you can assist. I have read most of this thread as I am trying to find the source of a loud banging noise that i get intermitently from my 2001 Allroad. The noise occurs occasionally usually early into a journey and usually when going over a bump etc. The noise is like a bang, bang, bang, bang which continues for maybe a minute, although will stop if the car comes to a halt, I press the up or down buttons on the ride height or I let it run and the noise will just stop eventually. The noise is a bit like a loud ABS system operating. the reason for asking here is that it appears to be linked to the air suspension. If its simply a matter of the compressor then I would be delighted.

Other details are:-
the height adjuster does work although I am unsure if it will go to level 4
I do not appear to have problems with leaks in the air bags.

Any help will be welcome.

[bagpipingandy]

Can anyone suggest what one wheel sinking intermittently, while parked, would indicate... Faulty valve?


BTW, changed my piston ring for an Andy one about three months back and still very pleased, pump runs like new!

Hi If the car sinks when parked at level 1 this is an airbag leak, test by parking at level 1 overnight, then see what its like in the morning, if it sinks to the bump stops park it at level 3 overnight, if it always sinks at level 1 but not at level 3 it is an airbag leak, what ever corner sinks the lowest has the leak. you can park in jack mode in level 1 only the leaking corner will sink

regards

Andy

[bagpipingandy]

I wonder if you can assist. I have read most of this thread as I am trying to find the source of a loud banging noise that i get intermitently from my 2001 Allroad. The noise occurs occasionally usually early into a journey and usually when going over a bump etc. The noise is like a bang, bang, bang, bang which continues for maybe a minute, although will stop if the car comes to a halt, I press the up or down buttons on the ride height or I let it run and the noise will just stop eventually. The noise is a bit like a loud ABS system operating. the reason for asking here is that it appears to be linked to the air suspension. If its simply a matter of the compressor then I would be delighted.

Other details are:-
the height adjuster does work although I am unsure if it will go to level 4
I do not appear to have problems with leaks in the air bags.

Any help will be welcome.

Hmm it could be the compressor coming off its mounts, the description of it stoping could be compressor related, the compressor will ussually start when you hit 15MPH for the 1st journey and run for 1-2 mins it will always stop running when the car halts too, if you press up to change level does it make this bang?

I suggest checking the compressor is still sitting on its 3 rubber mounts, it should sit on 3 springs and bounce around nicely without touching the car body, it is a violent running little thing if it is not fixed on its springs

let us know what you find

best regards

Andy