Strange Knocking Sound in Model S

[jaimearnold85]

I’ve been hearing a loud knocking sound in my 2013 model S. It does not do it all the time, the last time it did it was 4 months ago. It lasts 15-20 seconds and then stops. I’ve included the YouTube link to the video of the sound. It comes from the front of the car. Does anybody have any ideas??

 

[serendipitous]

Do you have the air suspension? Almost sounds like a compressor pump running.

 

[jaimearnold85]

Yes it has air suspension

 

[beatle]

See if you can replicate it while parked by raising the suspension.

 

[jaimearnold85]

We are definitely thinking it’s some sort of suspension problem. The car is now sitting so low that we don’t even feel safe driving it anywhere- and when we try to raise the suspension nothing happens. We’re unsure what to do at this point

 

[ij_eight]

It sounds like the air suspension system isn't holding air, and as a result the compressor is constantly running. The constant running probably destroyed the compressor, creating that noise.

 

[Rockster]

I believe a service call is warranted. I think the air suspension has malfunction.

 

[Aggmeister2010]

Yep, agreed with ij_eight. That sound is an unhappy compressor. Those air suspension compressors are only designed to run occasionally, and if you have a decent leak in your system, it'll overheat by running constantly.

And if it now doesnt make the noise, but also doesnt raise or lower on command, i'd say that just strengthens the hypothesis.

You're likely looking at the nasty job of hunting down an air leak in the air suspension lines or air struts, and then replacing the compressor.

I say nasty just because it's like finding a needle in a haystack usually...They have to basically get a fog machine around the suspension components and see where it's disturbed by leaking air blowing it.