Front Passenger side sagging

[David.X5]

Someone else reported something similar. It sounds like the air pump will "lock out" or "time out" if it's running too much. I have not seen any documentation on that though. The other one was fine after replacing the faulty rear air bag.

Of course, it is well known that the compressors will burn out if you let them run too much, such as with a leaky system, which is also a possibility here.

You should be able to check the sensors using inpa or something similar. Confirm they are reading in range. If it inflates to a correct level position when the key is on, I think that shows the sensor is working. Staying down all the time -may- point to a sensor, but it seems to have developed only after the other symptoms.

[ofcrimson]

Thank you David.X5. Once it warms up outside, I will do some additional troubleshooting.

[ofcrimson]

I have a friend that is a mechanic that is coming on Friday to change the air struts. What do you think is a fair price to pay him for his labor? He is going to change both air struts. I purchased the parts already. Thank you.

[David.X5]

There is a cool website called autoMD that lets you price standard jobs. You can put your zip in to get local pricing, too. With Arnott parts (L&R), it is saying $1500-$2300 for Maryland (sounds stupidly expensive to me). Knowing the parts are $700-$1100, so just using the averages, they are counting on about $1000 in labor (call that ~10 hours). Don't know what fraction of that you expect to pass along to your friend....

[ofcrimson]

Thank you David. This gives me a good place to start.

[cjett]

Originally Posted by David.X5

Someone else reported something similar. It sounds like the air pump will "lock out" or "time out" if it's running too much. I have not seen any documentation on that though. The other one was fine after replacing the faulty rear air bag.

Of course, it is well known that the compressors will burn out if you let them run too much, such as with a leaky system, which is also a possibility here.

You should be able to check the sensors using inpa or something similar. Confirm they are reading in range. If it inflates to a correct level position when the key is on, I think that shows the sensor is working. Staying down all the time -may- point to a sensor, but it seems to have developed only after the other symptoms.

The pump has a temperature sensor on it and when it overheats it activates the auto suspension inactive setting which shuts everything down and will throw a code on the display. The idea here is to try and save the motor on the pump.

I recently had a similar problem on my '03 e53 4.4 with 4 wheel air suspension and 140k miles. Passenger front was sagging and eventually led to the pump running often and then overheating. I replaced both front airshocks with arnott units and also rebuilt the pump with bagpiping andy's kit (which is terrific, btw) for good measure. Cleared the code and all was well.

Be sure to get an alignment afterward... Your mechanic can try to put the new shocks in the same location as the old ones by marking the bolt locations with a grease pencil (BMW suggests this in their documentation) but it's a guessing game, at best.

I've owned my vehicle since new and had the front air shocks replaced under warranty at 40k miles and now another set at 140k.!The rears have never been replaced - plan to tackle those this summer.

[David.X5]

Thanks. Do you know if the compressor will come back online after it cools or only after the code is cleared or something else?

[cjett]

Originally Posted by David.X5

Thanks. Do you know if the compressor will come back online after it cools or only after the code is cleared or something else?

As long as the motor is not actually burnt out, yes. It will fire right back up after resetting the code.

Edit - also worth nothing that you can disconnect the battery for 10 or so minutes and it should reset (if no faults are found). You don't need the BMW or other obd tools to reset the system... Although with the air suspension it is often worth connecting to an obd tool to pull the codes to see what you are dealing with. The following items are most likely (listed in order of most often encountered):
1. Air bags cracked (dry rot) or blown
2. Suspension level sensors on axles
3. Blown fuse or relays
4. Pump needs rebuilt (new piston seal)
4. Pump motor burnt out
5. Valve block, air hoses, air tank problems

[ofcrimson]

My mechanic friend came over today and replaced the air struts. We used Arnott remanufactured struts that I ordered from the Arnott website. So far the front passenger side is holding. I will let you know how it looks in the morning.

Summary of Symptoms prior to repair:
Front passenger side would lose air and the body would lower to just above the tire after sitting for a night. I did not have the suspesion inactive or any other error messages. When unlocking the vehicle (prior to starting) in the morning after the front passenger side lost air and lowered, the air strut would fill with air and raise to the normal height. I tried to locate the leak on the strut with soapy water, but was unable to find it.

[David.X5]

I'm glad its working. It would be great if you could post the rough parts cost and how long it took.