So a few days ago I replaced my E61 air suspension compressor. It didn't work so I returned it and bought one from another supplier. The new one has the same issue.
The compressor is installed and connected but when using INPA to test operation there is what I can only describe as the sound of an electric motor trying to run, but no air output.
All the valve solenoids sound to be operating correctly.
Is there something I haven't done with the installation or is it likely that the compressor itself is seized?
Edit: Just checked error codes after trying to run the compressor and i'm getting the error shown in the pic below.
Like the code suggests compressor relay would be the first call. That relay should always be renewed when replacing the compressor. Is your vehicle pre or post 9/2005?
It's a 2008 and I replaced the relay with the brand new one that came with the compressor (prior to that I had the relay from the compressor I thought was faulty in there - same problem). Also replaced the previously blown 40A fuse and I've checked every other fuse in the fuse box to be certain. The faulty unit had chewed up its innards and blown the 40A fuse. If its relevant, when I checked the relay after doing some tests with INPA it was quite warm.
That is what is confusing. There's obviously power getting to somewhere in the compressor assembly because there's an electronic whine when I activate the compressor using INPA, but no air.
My old compressor sounded more or less like a car tyre inflator which I'm guessing is the right sound. This sounds more like the compressor piston is seized and the motor is just spinning but it's exactly the same noise as the previous one I fitted which makes me think that isn't the issue.
I've only been able to replace one of the suspension air bags due to delivery issues with the other one so I tried using INPA to independently test that side but still nothing.
I was wondering if maybe the battery voltage was low (it's been parked for 10 days waiting for parts) or maybe the remaining air bag is completely shot and that is somehow causing the problem (although I would expect the compressor still to run).
My next thoughts unless someone offered a eureka suggestion was to maybe try 12V direct to the compressor, bypassing the relay to verify the compressor operation and/or getting stuck in with a multi-meter to check what is getting into the system.
Ok, So I've checked everything out with the multimeter. 12V is definitely being switched at the relay when I operate the compressor via INPA. Also get 12V at the compressor electrical connector.
There's an access plug for the compressor piston (see image of old compressor below)
I've removed this on the new compressor and can see that even though I can hear the sound of the new compressor motor energising, there's no movement of the piston.
This is the second new compressor with exactly the same issue so I'm wondering is there some trick I'm missing to get the piston moving?
Sounds like there is some problem on compressor supply (or ground) wiring so it doesn't get enough amps (poor connection, partially broken wire, etc.) Test the compressor with direct voltage so we can rule that out.
did you ever got if fixed? I am having exactly the same problem with a 2005 e61...
thanks
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
BMW Forums : BimmerForums
1.5M posts
270.5K members
Since 2007
A forum community dedicated to BMW owners and enthusiasts. Come join the discussion about performance, modifications, troubleshooting, M series, motorsports, maintenance, and more!