[FSJ Guy]

My air suspension will not go to the Load Level position.

It says "Pressure Tank Filling" in the dash display, but I don't hear the compressor running and I have verified via VCDS that the compressor is NOT being commanded to run, either.

I just had the compressor and pressure sensor swapped out because an air line blew out that was connected to the cylinder head assembly. I ran the adaptation on the Level Control Unit just in case, but there is no change.

The suspension also takes a long time to go both up AND down (longer than before the air line blew out and I had to replace the compressor), but it does go from Auto Level to Extra Height eventually. But it will not go to the Load Level position due to the error message.

Any thought? TIA!

 

[lgibson]

Do you have any faults stored? Be sure to erase any. It is normal that the computer wants to build pressure in the storage tank before releasing pressure in the struts. Slow filling is worrisome though, as it would seem to point to poor compressor performance. Check your MVB's for compressor performance.

 

[FSJ Guy]

The tech replaced the compressor, it did not run. Thinking the compressor was somehow coded to the vehicle, he reinstalled my original compressor with the replacement (used) head, which had the brown line fitting on it, which was broken on my original. It still did not run. He then swapped over the pressure sensor and it ran.

I'm wondering if swapping out the head caused a mismatch with the piston ring and if a piston ring rebuild kit would be helpful.

I also swapped out the temperature sensor, but it still shows ~70C when off (after just running) but immediately switches to over 200C when the compressor is running. Once it shuts off, it then immediately shows less than 100C and drops down to ~70C fairly quickly.

I have to button everything back up and then will back it out of the garage and look for a measuring value for compressor performance.

 

[lgibson]

How do we explain the slow deflation as well? I'm wondering about the possibility of a frozen or clogged dehumidifier media. IIRC this is incorporated into the head or close by.

 

[FSJ Guy]

I'm wondering if swapping out the head caused a mismatch with the piston ring and if a piston ring rebuild kit would be helpful.

With regards to my earlier thought (quoted above), I removed the compressor head again and installed the original piston ring that had been in that particular head.

The suspension raises up much faster now AND I am able to move it to Load Level without getting "Pressure Tank Filling" errors.

I think that the warning appears when the tank is being filled and the compressor turns off because of the duty cycle or excess temp being reported. Thus, the compressor is off, BUT the computer still thinks the compressor should be commanded ON, and therefore the error. <shrug>

That's my theory.

If it starts showing up again, I'll order one of the new piston rings that are sold on eBay.

For anyone else wanting/needing to do this, you DO NOT need to remove all the air lines from the valve block. I only bled down the pressure tank and removed the air lines from the compressor head (brown and black lines, IIRC). You can lower the compressor/valve block assembly and rest it on a suitable crate/box/whatever.

I did put the right hand side of the vehicle on ramps, however, just in case I needed to bleed the front and rear air springs, but that was not necessary.

 

[umliu365]

I also swapped out the temperature sensor, but it still shows ~70C when off (after just running) but immediately switches to over 200C when the compressor is running. Once it shuts off, it then immediately shows less than 100C and drops down to ~70C fairly quickly.

Based on the VAG-COM reading, my air compressor temperature sensor reading jump to a much higher reading when it is running(room temperature to hundreds, can not remember exactly) then as long as it stop running, immediately lower to 2 digits temperature.
After reading your post, now I think maybe it is normal.

 

[ech0sh4y]

So what was the fix for this issue?

 

[FSJ Guy]

I did end up replacing the piston ring. But I still get the pressure tank filling error fairly often. <shrug>

The solution at the moment is to put the suspension in "Sport" mode, which lowers it slightly from regular driving mode.

 

[nickyt]

I just realized that my 2006 has a timer on the compressor. Once that timer runs out, the compressor will not restart until the engine starts.

During some maintenance, I changed the height. It worked. Later I changed it again, it worked. Naturally you have to have the key turned to run for this to happen.

Later I tried to change it again. I got the "Pressure Tank Filling" and nothing happened. The compressor refused to turn on. Nothing would convince it to run. Took out key, put key back in, turned car to run position without cranking. I was tired; had finished just working on the Touareg.

Finally, being tired, I just threw up my hands and decided to move/park the Touareg and deal with this crap later.

I started the engine to move the Touareg, the %#$# compressor started also.

I felt like laughing, crying, breaking something, and taking that freaking nap all at the same instant. This must be what losing your mind feels like.

TL/DR: Start the freaking engine before you decide that air compressor is not working.

 

[FSJ Guy]

Another followup....

After replacing the piston ring AGAIN and still having "pressure tank filling" messages, I finally decided to just replace the ENTIRE compressor.

After several trips out, I feel confident in saying that the problem is fixed. It goes up, it goes down. Just as commanded. I think the problem was not in the piston ring OR the motor since the new motor sounds just like my old ones.

Instead, I think the piston HEAD was the culprit. There is a reed "valve" on the head. I think it was worn from use and either was not sealing or not opening as designed, thus the lowered air output.

The head is available separately, but I did not want to mess with it and just bought a clone compressor on eBay for $151 USD.

Hopefully there will be no more followups! (famous last words...)

 

[nickyt]

Hopefully there will be no more followups! (famous last words...)

It is good news that you got it fixed. :smile2:

If you think of it, give us a follow up later, on the success or failure of the "clone" compressor.

Many of us would like to use them, but don't won't to waste time if they are not going to hold up long term.

 

[Robert Markland]

Hi there im fairly new to this group. Ok heres my problem im battling with a customer's vw touareg v10. Ok heres what we did so far. 4x new shocks, new relay, new compressor, new i think you call it a air distribution block at the back of the compressor and it takes forever to raise and goes down slowly but to lower it to load level keeps on saying pressure tank filling but after a long while i connect the air pump under the drivers seat and there is no air so please im asking for advice please. Oh and ive also done the calibration like alot of times

Thank in advance