Hello! I have a lovely 2006 XJ8 that has had an air suspension fault. But, to me, it's strange. Sometimes the car will lower overnight as it sits in the driveway, but when I start it, it will raise back up (though it takes a good bit of time 5-10 minutes). Other times, the car, when parked, will stay fully lifted for days. This last time, the car stayed fully up for two weeks (parked - didn't drive it). Yet, as pointed out, at other times it will go from fully raised to flat overnight. How would you go about diagnosing this situation? I am not a mechanic, though I have done minor things like changed brakes, lights, air filters and the like. So, I am at a loss for what to look for. Why is the leak intermittent like that? Would that indicate more of a problem with the compressor than with one (or more) of the air shocks? Or would it indicate something else (a line or a lift sensor, etc.)?

Any help thinking this through would be much appreciated. Thanks!

 

Could be that it is temperature related.

Many posts about the suspension on these cars leaking when it gets below a certain ambient temperature.

If it takes a good 5-10 minutes to raise you could look for a leak during this time in the usual spots top of each strut or at the junction box in the trunk etc.

 

Thanks, jackra_1, but I don't think it's temperature related. The ASF has been on for a long time and the car lowers hot or cold, wet or dry, and does so intermittently (sometimes overnight, sometimes over days).

To look for the leaks at the top of each strut ... where do I look (sorry for being so ignorant here)? Do I have to remove anything from the car to do so?

 

The front struts are easily accessible as you can see the tops in the engine compartment. Rear not so much as you have to take out the trim in the trunk.

Also you can access the pressure cylinder tank and air junction box under the spare wheel.
Because it is intermittent it could be a difficult task unfortunately.

Spray soapy water over joins where the air tubing connects and also generally over the top of the struts to look for leaks. Also listen when the pump and engine is off when the car is at normal height.

Others will chime in I am sure.