07 S550: air suspension compressor

[kevm14]

I have been noticing the compressor is noisier than it used to be. I pulled it into the garage just now for an oil change and reflecting in the garage, even with the windows up, was more audible than it should have been. So I think change of plans. Instead of changing the oil, I'll order a compressor. Did some research on prices which I'll post but I think the conclusion is dealer reman.

Reman: A2213201704-80, two in stock
https://www.mercedesbenzpartsshop.com/o ... wtdjgtZ2Fz

New: A2213201704 (backordered at dealer, no price shown)
https://www.mercedesbenzpartsshop.com/o ... wtdjgtZ2Fz

And for good measure, I will replace the relay. A lot of times as the air compressors go, they draw excess current and partially kind of melt and a relay with resistance can damage a new compressor.

Relay: A0025422319, none in stock
https://www.mercedesbenzpartsshop.com/o ... wtdjgtZ2Fz

I did replace the air filter a little while back. But I also had at least two water fording events in the past and who knows what happened. Or just age/wear. It's probably original. No complaints.

[kevm14]

And for good measure, I will replace the relay. A lot of times as the air compressors go, they draw excess current and partially kind of melt and a relay with resistance can damage a new compressor.

Relay: A0025422319

I don't really need the instructions (it is an easy job) but look what I noticed.

W221 replace air compressor relay.PNG

[kevm14]

Price comparison for posterity.

RockAuto

Screenshot_20250913_074724_Edge.jpg

Screenshot_20250913_074837_Edge.jpg

FCP Euro
https://www.fcpeuro.com/Mercedes~Benz-p ... ic&b=Sedan

Dealer
https://www.mercedesbenzpartsshop.com/s ... 2213201704

I don't like Arnott generally but perhaps the air compressor is trust worthy enough. Oddly it is quite a bit cheaper on FCP Euro than Rockauto. The Bilstein is interesting but they are not the OEM and these days the name alone is no guarantee of anything. Back on FCP, AMK is actually the OEM supplier. Problem with that is, the dealer reman is only $6 more expensive. Given my Bosch steering rack experience recently, I think I'd happily just pay the $6 for reman that has a high reputation, and not play the "but it comes from the same production line" game.