Air suspension compressor issue

[Awntchi]

Hi all,

This is my first post on here and apologies in advance for any vital info I might have left out. My car is a 2005 E53 4.8iS with DSP and 4-corner air suspension.

I have read many forums about the infamous air suspension and its demons but so far none about the compressor itself. I myself have had all the airbags replaced, sensors fixed and compressor rebuilt. For each one of above mentioned fixes the car has responded well and functioned as it should, until the next issue appears.

Now to the latest issue which is probably the most annoying for me: For a few months now, every other day or so, when I start the car I get the suspension inactive warning on the dash....so I hook the car up and run the diagnostics which tells me the same fault every time: "storage pressure remains constant". Initially I thought the compressor was burnt so I went to take it out, after opening all the bolts (4x) around the case and flipped it over I thought I'll clear the codes and wiggle around with the wires to see if anything was loose first, before taking it out. That seemed to help, because the compressor came on straight away. I checked all connections and inside the piston and all seems fine, now every time the warning comes up I just reset it and give the compressor a bang with my palm (a slap if you'd like) and we're in business. The car raises up, down with no issues.

Does anyone know if the compressor is simply on its last legs or does the requirements of a slap actually point to a part in particular?

Thank you in advance for any suggestion.

/Awntchi

PS.I changed the piston ring, seals and bolts about 1,5 years ago...bought them from bagpipingandy on ebay.

[Ricky Bobby]

That code definitely points to the compressor - but seeing as you rebuilt it idk - did you rebuild the compressor before replacing the leaking air struts/bags?

[Awntchi]

Hi Ricky,

The last airbag I changed was the front right one, when I changed it and reset the fault, the compressor came on but the car didn't rise, not even a mm. So I bought the compressor refurb kit thinking maybe the compressor wasn't powerful enough...that didn't fix the issue though. I later noticed the level sensor on the same side had come off so I put it back and the car immediately lifted up the front. Since then everything has been working fine, the compressor comes on when it needs to and the ride is nice and smooth....until this problem.

A new observation this morning: The outside temperature is -20C and the following faults "magically" appeared..
1. The upper boot lid doesn't stay open...it's as if there is no pressure in the rods anymore (on both). They are no more than 1 year old.
2. Brand new and high end battery was dead (although it took 5 min to get it back to 85% before i started the car). It's no more than 3 months old.
3. The compressor didn't come on and the "slap" didn't work either.

Any ideas....could it really be the cold temp...?

[Ricky Bobby]

Check your battery voltage when running - your alternator could be on the way out and not able to keep your battery charged, esp if it was new

[Awntchi]

Sorry for late reply. I finally had a chance to check the voltage and all seems ok, 12.3 when is running.

I've now received a second warning from the comp, overheating. This must be due to one of the airbags being on it's way out...I hope it will hold until the weather improves. I'll recond the comp and change airbag as a start....we'll see.

Thanks for your help Ricky

[Ricky Bobby]

12.3v while the car is running is extremely low, should be between 13-14

[Awntchi]

Ricky, I've just come back from double checking the voltage and i don't know where i got the 12v from...it is actually 14.3v +/- 0.15.

I must have been thinking about my upcoming project that requires 12v outlets

Sent from my SM-G900F using Tapatalk

[Ricky Bobby]

^Whoops nvm you are good to go then!