Let us help you diagnose and fix your BMW X5 and X6 air bag suspension problems - they don't need to be another expensive repair!
Rear axle air bag suspension was a popular option on many BMW X5 and X6 models (2006 E70 series onwards) for those looking for maximum comfort, towing large boats and horse floats. It was a standard feature on 7 seater models.
The air bag springs are largely made of rubber and will eventually need replacement as they bear a heavy load while exposed to the elements, dirt, grit and sand. There can be some early warning signs of impending doom such as a droopy rear on one side, or both sides. It is vital to take action as soon as possible when you notice this to prevent damaging other components and multiplying the repair bill. Occasionally the air bag springs may suddenly burst while driving, requiring an expensive tow.
Here is our advice on the common symptoms you may experience on your BMW X5 or X6. We always recommend professional diagnosis as there can be other causes, however, many of these repairs are surprisingly easy to accomplish:
1. Droopy rear on one corner which goes back up after the engine is started: At least one air spring has developed a small puncture and will require replacement. We recommend replacing both at this stage.
2. Droopy rear on both sides which goes back up after the engine is started, no hissing noise heard near back wheels: Both air springs have small punctures. Both air springs must be replaced.
Note: If the suspension sags frequently (overnight, or after being parked for a few hours), the expensive air compressor is being overworked. In normal use, the compressor only briefly operates to maintain the height of the rear with varying loads. When there are punctures in the air bag spring/s, the compressor operates both more frequently to reinflate the leaked air bag spring and also for longer due to the leaked air.
3. Droopy rear (one side or both) which does not go back up after the engine is started, hissing noise can be heard near the back wheels: Air bag spring/s have large punctures or ruptured. Both air bag springs must be replaced. Do not drive your vehicle as the shock absorbers will be taking the brunt of any bumps. It will be extremely uncomfortable and unsafe to drive in this condition.
4. Droopy rear (one side or both) which does not go back up after the engine is started. No hissing noise from the back wheel area, and no compressor sound can be heard near the driver's door (front right): Check compressor relay and fuse. The location varies. E7x models have it installed in the front. F1x and F8x models have both fuse and relay in the rear right compartment.
More than likely, the compressor has worn out from frequent reinflation and no longer supplies sufficient pressure or air volume to reinflate the air bag springs.
It is important to note that air bag suspension repairs can become very costly if faults are not rectified promptly. If your X5 or X6 sags overnight or even after being parked for an hour, the compressor is doing a year's worth of work in the space of a few days. The compressor is an expensive component as it is only available from BMW complete with the valve body. A failure of either the compressor or valve body will require complete replacement. We strongly recommend replacement of the relay which supplies power to the compressor due to the high current carried by this circuit.
Following replacement of the compressor, ensure the air bag springs are thoroughly inspected for leaks.
Leak checks can be easily carried out with the rear jacked up and supported with jack stands or on a hoist by your mechanic. The use of soapy water in a spray bottle is ideal for this task. Once sprayed on, check in 5 minutes for bubbles or a shaving foam-like appearance indicating pinhole leaks.
BMW X5 and X6 air suspension problems are easy to fix and quite simple to diagnose. If you need further help or advice, please reach out to our resident BMW trained expert at firstname.lastname@example.org